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Notepad++ with the C# compiler - you can do it
if you ever decided to to work a bit outside of visual studio and configure a plain text editor to work with the c# compiler, you most likely know that it's not so straightforward as it might seem. at first, i thought that it would be a relatively easy task to add a specific compiler reference to notepad++ , but it needed some additionalwork, as notepad++ has no specific wizard or dialog to directly configure a custom compiler. however, there is a run box (found in the run menu) that can help you solve many problems: there are two ways to use a compiler - either use the ... button and specify the path to the compiler, and then save it, or you could configure the path environment variable and use the compiler directly from the command line by calling the executable name. i am going to start with the second option - set the specific path variable and then use csc (the c# compiler) from inside notepad++. the reason behind this is that sometimes you will want to compile from the console (without an ide or text editor) and this will make the task a lot easier. not that you will encounter this scenario very often, but it is always a great plus to know how it can be automated - for example, you might want to have some compilation scripts later. before going any further, i tried to see how to set all correct path references so that i will make the system console .net-enabled (excluding the option of running the visual studio command prompt bundled with the vs release you have). in the program files folder (or the host folder where you installed visual studio) there is the visual studio x.0 folder (replace x with the most recent version of visual studio installed on the machine). in the common7 folder you will find the tools folder and this is the final destination for now. run the command prompt ( winkey+r , cmd ) and simply drag the vsvars32.bat file in the console. then, just press enter and the path variable will be automatically set so that you can run .net tools from the command line. technically, this would be the same procedure as if you would run the visual studio command prompt, but now you know how this process actually starts. note: don't run the bat file directly from windows explorer, as it will have no effect - it only sets the environment variables for the current session. once you have the path variable set, you need to get the newly-set values to make them permanent, and not only for the current session. let's do it the simple way - just save the console output for the path in a text file. to do this, just type in the console (make sure you are in the folder you want the file to be saved into): path > mypath.txt close the command prompt and go to the text file you just saved. copy everything after path= . go to the system properties dialog ( winkey+pause break ) and find the advanced sytem settings (it's called so in windows vista and 7 - not entirely sure about previous versions). in the advanced tab is the environment button and this is exactly what's needed. click it and you will see that there are two lists of environment variables in the new dialog. the first one is for the current user and the second one is for system-wide environment variables. select path from system variables and edit it. completely replace the existing string with the one you just copied and click ok. to test the new settings, try opening the command prompt and simply type csc. the output should look like this: awesome! so the compiler can be accesed without explicitly specifying the path. let's go to notepad++ and configure it to work with csc . type a simple c# program in the editor: using system;namespace consoleapplication{class program{static void main(string[] args){console.writeline("sample");console.readline();}} click on run > run... . you will now need to enter the program to be used to compile the file. there are several internal environment variables that you can use the supply the file name to the compiler, since passing the direct path to one file is not exactly what i wanted - after all, i want to re-use the capability. suppose that you saved your file (and it should be saved before compiling) as c:\documents\myfiles\sample.cs . there are a couple of internal variables (specific to notepad++) that can be used to reference the file you are currently working with: full_current_path - is the full path to file - c:\documents\myfiles\sample.cs current_directory - just the directory where the file is located - c:\documents\myfiles file_name - the file name only - sample.cs name_part - the part that only shows the name of the file without the extension - sample ext_part - the file extension - cs you need to use the full path to compile the file, so here goes the actual command: csc.exe $(full_current_path) why type the exe extension? because there is a csc folder in the system folder, and typing only csc will result in opening the folder instead of launching the compiler. the above command will create an executable with the same name as the source file in the user folder. if you want to specify another folder for the executable to be built in, use the out parameter: csc.exe /out:"d:\temporary\myfile.exe" $(full_current_path) once the command is working you can save it in from the run dialog for easy re-use. note: you can customize the command line parameters for the compiler as you want - after all, you might want to compile a library and reference additional assemblies.
January 19, 2011
by Denzel D.
· 65,002 Views
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Deterring “ToMany” Relationships in JPA models
This article considers the issues of one to many relationships from the JPA model, and looks at an alternative strategy to provide more efficient and fine grained data access, to build more robust and lightweight applications and web services. A fairly typical use is to have one entity ‘owned’ by the other in such a way that one entity is said to ‘have’ many instances of the other one. A typical example would be customer and orders : class Customer { @OneToMany(mappedBy="customer") private Set orders; } class Order { @ManyToOne private Customer customer; } In this trivial example, the order belongs to a customer, and the customer has a set of orders. We don’t have a problem with the ManyToOne relationship, especially as it is required in order to map the order back to the customer. When we load an order we will at most get a single reference to a customer. No, our problem is with the value we get from customer.getOrders() as this set of order entities doesn’t really serve any useful purpose and can cause more problems than it solves for the following reasons : Dumb Relationship – It will contain every order for this particular customer when you usually only want a subset of the orders that match a set of criteria. You either have to read them all and filter the ones you don’t want manually (which is what SQL is for) or you end up having to make a call to a method to get the specific entities you are interested in. Unbounded dataset – How many orders a customer has could vary and you could end up with a customer with thousands of orders. Combined with accidental eager fetching and loading a simple list of 10 people could mean loading thousands of entities. Unsecured Access – Sometimes we may want to restrict the items visible to the user based on their security rights. By making it available as a property controlled by JPA we lose that ability or have to implement it further down in the application stack. No Pagination – Similar to the unbounded dataset, you end up throwing the whole list into the pagination components and letting them sort out what to display. In most cases, you need to treat each dataset like it will eventually contain more than 30 records so you really need to consider pagination early. Overgrown object graph – When you request an entity, how much of the object graph do you need? How do you know which pieces to initialize so you can avoid LIEs? This is often the case with JPA, but is also more relevant when you take account of the needs to serialize object graphs to XML or JSON. Sometimes you might need the relationships and sometimes you do not depending on the context you will be using the data in. Rife with pitfalls – Who saves and cascades what and how do you bind one to the other? You create an order, and assign the customer, do you need to then add it to the customers list of orders or not. What happens if you forget to add it to the customer and you save the customer? Whatever strategy you pick for dealing with this will no doubt end up being implemented inconsistently. (Ok, the first four are really different facets of the same problem, that you can’t control the data you are getting back.) So what use are they? Well, they make it really tempting just to use customer.orders in the view which is suitable for some sets of data. They also allow the relationship to be used in ejbql statements, although the inverse of the relationship can also be used in most cases. Specifying this relationship can also allow you to cascade updates/deletes from the customer to the order, but then so can your database. Going Granular The best alternative I’ve found is to provide additional methods to obtain the relational information separate from the model. This more granular approach gives you plenty of ways of obtaining data from the database without the dangers and temptations of bad practices. For example, the Order object still has the Customer reference on it, which we use to obtain lists of orders from the data access layer which can be constrained by customer, time frame, or other criteria depending on where it is being used. Also, it allows data to be fetched when needed without having to define a single initialization strategy using annotations or mapping files. The code that knows what pieces of data it needs will have access to facilities to fetch the specific data it needs. Alternatively, the methods to fetch the data can either be exposed as web services directly or DTO objects can be used to build a data payload to be returned from a single web service that consolidates the calls. Regardless, you don’t need to worry about setting the JPA fetch or XML/JSON serialization policy permanently in the model. Some examples might be to fetch orders for a customer in different ways. public List getOrders(Long customerId) {...} public List getOrders(Long customerId,Date startDate,Date endDate) {...} public List getOrders(SearchCriteria searchCriteria,int firstResult,int pageSize) {...} What about @ManyToMany Good question. In most cases I find that what starts as a many to many relationship can usually be modeled as a separate entity because when you create a many to many relationship, there is usually additional information stored with that relationship. For example, a Users and Groups ManyToMany relationship has many users belonging to many groups and vice versa. The membership however also probably has start and end dates and also maybe a role within that group. This also exhibits one of the earlier problems in that user.getGroupMemberships() would return all group memberships past and present whereas you probably only want the active ones. Modeling it as a separate entity means it becomes an entity with two OneToMany relationships. While there are cases where the many to many relationship is literally just a pair of ids (think blog post tags, many tags to many posts), you could benefit at a later date by using an entity if you decide to add additional information into the relationship. In summary, moving relational fetches out of the data model and into the data layer means you remove some of the temptations of bad practices and create a library of reusable functions for fetching the data that can be used from different code points. From http://www.andygibson.net/blog/article/deterring-tomany-relationships-in-jpa-models/
January 18, 2011
by Andy Gibson
· 23,333 Views · 1 Like
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Migrating from JBoss 4 to JBoss 5
I have been using JBoss 4.2.3 for over a year right now and really like it (although the clustering / JMS stuff seems WAY overcomplicated - and needing 80 config files - not fun!). But anyway it is time to upgrade to JBoss 5 and the path has been marred by many stops and starts and has been surprisingly difficult. In any event I found the following links to be a life saver and thought I would share them http://community.jboss.org/wiki/MigrationfromJBoss4.pdf http://venugopaal.wordpress.com/2009/02/02/jboss405-to-jboss-5ga/ http://www.tikalk.com/java/migrating-your-application-jboss-4x-jboss-5x The real kickers have to be 1) Increased adherence to the Java spec that cause WARs / JARs to no longer deploy 2) Changed location of XML files 3) Changed XML filenames 4) Changed XML file contents Man they don't make it easy do they? From http://softarc.blogspot.com/2011/01/migrating-from-jboss-4-to-jboss-5.html
January 14, 2011
by Frank Kelly
· 20,537 Views
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EMF Tips: Accessing Model Meta Data, Serializing into Element/Attribute
Two tips for the Eclipse Modeling Framework (EMF) 2.2.1: Accessing model’s meta model – accessing EClass/attribute by name – so that you can set an attribute when you only know its name and haven’t its EAttribute How to force EMF to serialize an object as an XML element instead of an XML attribute Excuse my rather liberal and slightly confusing use of the terms model, model instance and meta model. Tip 1: Accessing model’s meta model – accessing EClass/attribute by name Normally you cannot do any operation on a dynamic EMF model instance – such as instantiating an EObject or settings its property via eSet – without the corresponding meta model objects such as EClass and EAttribute. But there is a solution – you can build an ExtendedMetaData instance and use its methods to find the meta model objects based on search criteria such as element name and namespace. Examples Create ExtendedMetaData from a model One way to build a meta data instance is to instantiate BasicExtendedMetaData based on a Registry, containing all registered packages. This is usually available either via ResourceSet.getPackageRegistry() or globally, via EPackage.Registry.INSTANCE. import org.eclipse.emf.ecore.util.*; ... ExtendedMetaData modelMetaData = new BasicExtendedMetaData(myResourceSet.getPackageRegistry()); Get EClass for a namespace and name Provided that your model contains an element with the name Book and namespace http://example.com/book: EClass bookEClass = (EClass) modelMetaData.getType("http://example.com/book", "Book"); Get EClass’ attribute by name Beware: Some properties (such as those described by named complex types) are not represented by an EAttribute but an EReference (both extend EStructuralFeature) and are accessible as the EClass’ elements, not attributes, even though from developer’s points of view they’re attributes of the owning class. Let’s suppose that the book has the attribute name: EStructuralFeature nameAttr = modelMetaData.getElement(bookEClass, null, "name"); The namespace is null because normally attributes/nested elements are not classified with a schema. Here is how you would print the name and namespace URI of an attribute/element: System.out.println("attr: " + modelMetaData.getNamespace(nameAttr) + ":" + nameAttr.getName()); //prints "null:name" Tip 2: How to force EMF to serialize an object as an XML element instead of an XML attribute Normally EMF stores simple Java properties as attributes of the XML element representing the owning class: but you might prefer to have it rather as a nested element: The Book of Songs To achieve that: Enable the save option OPTION_EXTENDED_META_DATA (so that extended meta data such as annotations and an XML map aren’t ignored) Tell EMF that you want this property to be stored as an element By attaching an eAnnotation to it (not shown) By supplying a XML Map with this information upon save To enable the extended metadata: Map saveOptions = new HashMap(); saveOptions.put(XMLResource.OPTION_EXTENDED_META_DATA, Boolean.TRUE); According to some documentation the value should be an implementation of ExtendedMetaData, according to others Boolean.TRUE is the correct choice – I use the latter for it’s easier and works for me. To tell EMF to write a property as an element when serailizing to XML: import org.eclipse.emf.ecore.xmi.impl.*; ... EAttribute bookNameEAttribute = ...; // retrieved e.g. from meta data, see Tip 1 XMLMapImpl map = new XMLMapImpl(); XMLInfoImpl x = new XMLInfoImpl(); x.setXMLRepresentation(XMLInfoImpl.ELEMENT); map.add(bookNameEAttribute, x); saveOptions.put(XMLResource.OPTION_XML_MAP, map); The XMLInfoImpl enables you to customize the namespace, name and representation of the element. When saving you then just supply the save options: EObject target = ...; org.eclipse.emf.ecore.resource.Resource outResource = ...; outResource.getContents().add(target); outResource.save(saveOptions); Reference: the Redbook Eclipse Development using the Graphical Editing Framework and the Eclipse Modeling Framework, page 74, section 2.3.4 From http://theholyjava.wordpress.com/2011/01/11/emf-tips-accessing-model-meta-data-serializing-into-elementattribute/
January 12, 2011
by Jakub Holý
· 14,626 Views
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Are the JPA callback methods useful?
Definitely no. The section 3.5 of JPA specification states: “In general, the lifecycle method of a portable application should not invoke EntityManager or Query operations, access other entity instances, or modify relationships within the same persistence context. A lifecycle callback method may modify the non-relationship state of the entity on which it is invoked.” Surely these restrictions has a good technical reason behind them, but from a business application developer perspective they mean that JPA callback methods are practically useless. For example, these scenarios are typical: In order to remove some entity we need to verify if some data exists, and we want do it using a JPA query. When an entity is saved, some other entities must be automatically created and saved, and we want to use the JPA EntityManager to do so. Unfortunately, it’s difficult to solve such cases using the standard annotations: @PrePersist, @PostPersist, @PreRemove, @PostRemove, @PreUpdate, @PostUpdate or @PostLoad. In order to remove some entity we need to verify if some data exists, and we want do it using a JPA query. When an entity is saved, some other entities must be automatically created and saved, and we want to use the JPA EntityManager to do so. Unfortunately, it’s difficult to solve such cases using the standard annotations: @PrePersist, @PostPersist, @PreRemove, @PostRemove, @PreUpdate, @PostUpdate or @PostLoad. What can we do? We have several options such as: Using JDBC from the callback methods: Horror! Create a new EntityManager in the callback method: This works sometimes, but you can have problems with isolation levels. Moreover, you lose the transactional behavior. Put the on-save or on-remove logic in the controller layer, that is in the actions: Of course, this works just fine, but if you access to the entities from other actions, from a batch process, or from a web service, the on-logic or on-remove will not be executed. Obviously, these options are dirty and unnatural, and even even worse, they mean more work for us. Create your own callback annotations In OpenXava, we have opted for the simplest solution for the poor application developer, just creating some new callback annotations that allow to use JPA inside them. OpenXava 4.0.1 includes the next new annotations: @PreCreate, @PostCreate and @PreDelete. For example, if we need to create a customer and assign it to an invoice when the customer is not specified, you can write: @PreCreate public void onPreCreate() { // Automatically create a new customer if (getCustomer() == null) { Customer cust = new Customer(); cust.setName(getName()); cust.setAddress(getAddress()); cust = XPersistence.getManager().merge(cust); // Here we use the EntityManager setCustomer(cust); // and here we change a relationship } } If you want to enjoy these annotations just use OpenXava for developing your application. Although if you are not still ready for rapid development, you can create these annotations yourself easily, just use the decorator pattern over the EntityManager or use AOP to refine the behavior of persist() and remove() methods. Learn more about these annotations
January 12, 2011
by Javier Paniza
· 15,313 Views · 1 Like
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Interview: Troy Giunipero, Author of NetBeans E-commerce Tutorial
Troy Giunipero (pictured, right) is a student at the University of Edinburgh studying toward an MSc in Computer Science. Formerly, he was one of the NetBeans Docs writers based in Prague, Czech Republic, where he spent most of his time writing Java web tutorials. In this interview, Troy introduces you to The NetBeans E-commerce Tutorial. This is a very detailed tutorial describing just about everything you need to know when creating an e-commerce web application in Java. It has received a lot of very positive feedback. Let's find out about the background of this tutorial and what Troy learnt in writing it. Hi Troy! During your time on the NetBeans team, you wrote a very large tutorial describing how to create an e-commerce site. How and why did you start writing it? Well, there’s a short answer and a long answer to this. The short answer is that I was lucky to take part in Sun’s SEED (Sun Engineering Enrichment and Development) program. I wanted to focus on technical aspects, so I based my curriculum on developing an e-commerce application using Java technologies. I documented my efforts and applied them toward deliverables for the IDE’s 6.8 and 6.9 releases, resulting in the 13-part NetBeans E-commerce Tutorial. The long answer is that I had previously been tasked with creating an e-commerce application for my degree project (I was studying toward a BSc in IT and Computing), and ran into loads of trouble trying to integrate the various technologies into a cohesive, functioning application. I was coming from a non-technical background and found there was a steep learning curve involved in web development. My work was fraught with problems which I can now attribute to poor time-management, and a lack of good, practical, hands-on learning resources. So in a way, working on the AffableBean project (this is the project used in the NetBeans E-commerce Tutorial) was a way for me to go back and attempt to do the whole thing right. With the tutorial, I had two goals in mind: one, I wanted to consolidate my understanding of everything by writing about it, and two, I wanted to help others avoid the problems and pitfalls that I’d earlier ran into by designing a piece of documentation that puts everything together. Can you run us through the basic parts and what they provide? Certainly. First I want to point out that there’s a live demo application (http://dot.netbeans.org:8080/AffableBean/) which I managed to get up and running with help from Honza Pirek from the NetBeans Web Team (thanks Honza!): The application is modeled on the well-known MVC architecture: The tutorial refers to the above diagram at various points, and covers a bunch of different concepts and technologies along the way, including: Project design and planning (unit 2) Designing a data model (using MySQL WorkBench) (unit 4) Forward-engineering the data model into a database schema (unit 4) Database connectivity (units 3, 4, 6) Servlet, JSP/EL and JSTL technologies (units 3, 5, 6) EJB 3 and JPA 2 technologies (unit 7), and transactional support (unit 9) Session management (i.e., for the shopping cart mechanism) (unit 8) Form validation and data conversion (unit 9) Multilingual support (unit 10) Security (i.e., using form-based authentication and encrypted communication) (unit 11) Load testing with JMeter (unit 12) Monitoring the application with the IDE’s Profiler (unit 12) Tips for deployment to a production server (units 12, 13) Also, the tutorial aims to provide ample background information on the whole “Java specifications” concept, with an introduction to the Java Community Process, how final releases include reference implementations, and how these relate to the tutorial application using the IDE’s bundled GlassFish server (units 1, 7). Finally, the tutorial is as much about the above concepts and technologies as it is about learning to make best use of the IDE. I really tried to squeeze as much IDE-centric information in there as possible. So for example you’ll find: An introduction to the IDE’s main windows and their functions (unit 3) A section dedicated to editor tips and tricks (unit 5), and abundant usage of keyboard shortcuts in steps throughout the tutorial Use of the debugger (unit 8) Special “tip boxes” that discuss IDE functionality that is sometimes difficult to fit into conventional documentation. For example, there are tips on using the IDE’s Template Manager (unit 5), GUI support for database tables (unit 6), Javadoc support (unit 8), and support for code templates (unit 9). Did you learn any new things yourself while writing it? Yes! Three things immediately come to mind: EJB 3 technology. Initially this was a big hurdle for me. Using EJB 3 effectively seems to be something of an art form. If you know what you’re doing and understand exactly how to use the EntityManager to handle persistence operations on a database, EJB lets you do some amazingly smart things with just a few lines of code. But there seems to be a lack of good free documentation online—especially since EJB 3 is a significant departure from EJB 2. Therefore, almost all of the tutorial’s information on EJB comes from the very excellent book, EJB in Action by Debu Panda and Reza Rahman. Interpreting the NetBeans Profiler. The final hands-on unit, Testing an Profiling, was the most difficult for me to write, primarily because I just wasn’t familiar with the Profiler at all. I spent an unhealthy amount of time just watching the Telemetry graph run against my JMeter test plan, which is only slightly more stimulating than watching water come to boil. That being said, I feel that by just examining the graphs and other windows over time, critical logical associations start to jump out at you after a while. Likewise with JMeter. Hopefully unit 12 was able to capture and relay some of these. How to search online for decent articles and learning materials. The old Sun Technical Articles site was a great resource. Many of the links in the See Also sections at the bottom of tutorial units were found by adding site:java.sun.com/developer/technicalArticles/ to a Google search. Also the official forums (found at forums.sun.com) became a good place for questions I couldn’t find ready answers to. I had both the Java EE 5 and 6 Tutorials bookmarked. And Marty Hall’s Core Servlets and JavaServer Pages became an invaluable resource for the first half of the tutorial. What are your personal favorite features of the technologies discussed in the tutorial? I particularly liked learning about session management—using the HttpSession object to carry user-specific data between requests, and working with JSP’s corresponding implicit objects in the front-end pages. Session management is a defining aspect for e-commerce applications, as they need to provide some sort of shopping cart mechanism... ...and so the Managing Sessions unit (unit 8) was a key chapter in the tutorial. It’s extremely useful to be able to suspend the debugger on a portion of code that includes session-scoped variables, then hover the mouse over a given variable in the editor to determine its current value. I used the debugger continuously during this phase, and so I went so far as to incorporate use of the debugger throughout the Managing Sessions unit. What kind of background does someone starting the tutorial need to have? Someone can come to the tutorial with little or absolutely no experience using NetBeans. I’ve tried to be particularly careful in providing clear and easy-to-follow instructions in this respect. But one would be best off having some background or knowledge in basic web technologies, and at least some exposure to relational databases. With this foundation, I think that the topics covered in the second half of the tutorial, like applying entity classes and session beans, language support and security, won’t seem too daunting. I’ve noticed that the vast majority of feedback that comes in relates to the first half of the tutorial, and I sometimes get the impression that people feel they need to follow the tutorial units consecutively. Not so. The units are 90% modular. In other words, if somebody just wants to run through the security unit (unit 11), they can do so by downloading the associated project snapshot, follow the setup instructions, and then just follow along without needing to even look at other parts of the tutorial. What will they be able to do at the end of it? Naturally, anybody who completes individual tutorial units will be able to apply the concepts and technologies to their own work. But anyone who completes the tutorial in its entirety will gain an insight into the development process as a whole, and I think will also get a certain confidence that comes with knowing how “all the pieces fit together”—from gathering customer requirements all the way to deployment of the completed app to a production server. They’ll also have gained a solid familiarity with the NetBeans IDE, and be in a good position to explore popular Java web frameworks that work on top of servlet technology or impose an MVC architecture on their own, such as JSF, Spring, Struts, or Wicket. Do you see any problems in the technologies discussed and what would be your suggestions for enhancements? Well there’s one thing that comes to mind. When I started working on this project, I was studying the Duke’s BookStore example from the Java EE 5 Tutorial. A wonderful example that demonstrates how to progressively implement the same application using various technologies and combinations thereof. So for example you start out with an all-servlet implementation, then move on to a JSP/servlet version. Then there’s a JSTL implementation and ultimately, a version using JavaServer Faces. It’s great learning material, but also terrifically outdated. Right around this time, Sun was gearing up for the big Java EE 6 release (Dec. 2009), and I was also trying to learn about the new upcoming technologies, namely CDI, JSF 2, and EJB 3, for my regular NetBeans documentation work. I was getting the definite sense that JSP and JSTL were slowly being pushed aside—in the case of JavaServer Faces, Facelets templating was the new page authoring technology. So really, the E-commerce Tutorial application has become a sort of EE 5/EE 6 hybrid by combining JSP/JSTL with EJB 3 and JPA 2. Now the problem I see from the perspective of a student trying to learn this stuff from scratch, is that the leap from basic servlet technology to a full-blown JSF/EJB/JPA solution is tremendous, and cannot readily be taught through a single tutorial. Naturally, others may disagree with me here. I’m not sure if there’s a solution other than to compensate by producing a lot of quality learning material that covers lots of different use-cases. I’d suggest that the E-commerce Tutorial puts one in a very advantageous position to begin learning about Java-based frameworks, such as GWT, Spring, and JSF, which is a natural course of action for people looking to get a job with this knowledge. Planning any more parts to the tutorial or a new one? No more parts. The E-commerce Tutorial is done. Upon committing the final installments and changes last November, I rejoiced. However, I’m still actively responding to feedback [the ‘Send Us Your Feedback’ links at the bottom of tutorials] and plan to maintain it indefinitely, so if anyone spots any typos, has questions or comments, recommendations for improvement, etc., please write in! :-)
January 9, 2011
by Geertjan Wielenga
· 30,236 Views
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Clojure: select-keys, select-values, and apply-values
Clojure provides the get and get-in functions for returning values from a map and the select-keys function for returning a new map of only the specified keys. Clojure doesn't provide a function that returns a list of values; however, it's very easy to create such a function (which I call select-values). Once you have the ability to select-values it becomes very easy to create a function that applies a function to the selected values (which I call apply-values). The select-keys function returns a map containing only the entries of the specified keys. The following (pasted) REPL session shows a few different select-keys behaviors. user=> (select-keys {:a 1 :b 2} [:a]) {:a 1} user=> (select-keys {:a 1 :b 2} [:a :b]) {:b 2, :a 1} user=> (select-keys {:a 1 :b 2} [:a :b :c]) {:b 2, :a 1} user=> (select-keys {:a 1 :b 2} []) {} user=> (select-keys {:a 1 :b 2} nil) {} The select-keys function is helpful in many occassions; however, sometimes you only care about selecting the values of certain keys in a map. A simple solution is to call select-keys and then vals. Below you can find the results of applying this idea. user=> (def select-values (comp vals select-keys)) #'user/select-values user=> (select-values {:a 1 :b 2} [:a]) (1) user=> (select-values {:a 1 :b 2} [:a :b]) (2 1) user=> (select-values {:a 1 :b 2} [:a :b :c]) (2 1) user=> (select-values {:a 1 :b 2} []) nil user=> (select-values {:a 1 :b 2} nil) nil The select-values implementation from above may be sufficient for what you are doing, but there are two things worth noticing: in cases where you might be expecting an empty list you are seeing nil; and, the values are not in the same order that the keys were specified in. Given that (standard) maps are unsorted, you can't be sure of the ordering the values. (side-note: If you are concerned with microseconds, it's also been reported that select-keys is a bit slow/garbage heavy.) An alternative definition of select-values uses the reduce function and pulls the values by key and incrementally builds the (vector) result. user=> (defn select-values [map ks] (reduce #(conj %1 (map %2)) [] ks)) #'user/select-values user=> (select-values {:a 1 :b 2} [:a]) [1] user=> (select-values {:a 1 :b 2} [:a :b]) [1 2] user=> (select-values {:a 1 :b 2} [:a :b :c]) [1 2 nil] user=> (select-values {:a 1 :b 2} []) [] user=> (select-values {:a 1 :b 2} nil) [] The new select-values function returns the values in order and returns an empty vector in the cases where previous examples returned nil, but we have a new problem: Keys specified that don't exist in the map are now included in the vector as nil. This issue is easily addressed by adding a call to the remove function. The implementation that includes removing nils can be found below. user=> (defn select-values [map ks] (remove nil? (reduce #(conj %1 (map %2)) [] ks))) #'user/select-values user=> (select-values {:a 1 :b 2} [:a]) (1) user=> (select-values {:a 1 :b 2} [:a :b]) (1 2) user=> (select-values {:a 1 :b 2} [:a :b :c]) (1 2) user=> (select-values {:a 1 :b 2} []) () user=> (select-values {:a 1 :b 2} nil) () There is no "correct" implementation for select-values. If you don't care about ordering and nil is a reasonable return value: the first implementation is the correct choice due to it's concise definition. If you do care about ordering and performance: the second implementation might be the right choice. If you want something that follows the principle of least surprise: the third implementation is probably the right choice. You'll have to decide what's best for your context. In fact, here's a few more implementations that might be better based on your context. user=> (defn select-values [m ks] (map #({:a 1 :b 2} %) ks)) #'user/select-values user=> (select-values {:a 1 :b 2} [:a]) (1) user=> (select-values {:a 1 :b 2} [:a :b :c]) (1 2 nil) user=> (defn select-values [m ks] (reduce #(if-let [v ({:a 1 :b 2} %2)] (conj %1 v) %1) [] ks)) #'user/select-values user=> (select-values {:a 1 :b 2} [:a]) [1] user=> (select-values {:a 1 :b 2} [:a :b :c]) [1 2] Pulling values from a map is helpful, but it's generally not the end goal. If you find yourself pulling values from a map, it's likely that you're going to want to apply a function to the extracted values. With that in mind, I generally define an apply-values function that returns the result of applying a function to the values returned from specified keys. A good example of this is returning the total for a line item represented as a map. Given a map that specifies a line item costing $5 and having a quantity of 4, you can use (* price quantity) to determine the total price for the line item. Using our previously defined select-values function we can do the work ourselves, as the example below shows. user=> (let [[price quantity] (select-values {:price 5 :quantity 4 :upc 1123} [:price :quantity])] (* price quantity)) 20 The example above works perfectly well; however, applying a function to the values of a map seems like a fairly generic operation that can easily be extracted to it's own function (the apply-values function). The example below shows the definition and usage of my definition of apply-values. user=> (defn apply-values [map f & ks] (apply f (select-values map ks))) #'user/apply-values user=> (apply-values {:price 5 :quantity 4 :upc 1123} * :price :quantity) 20 I find select-keys, select-values, & apply-values to be helpful when writing Clojure applications. If you find you need these functions, feel free to use them in your own code. However, you'll probably want to check the comments - I'm sure someone with more Clojure experience than I have will provide superior implementations. From http://blog.jayfields.com/2011/01/clojure-select-keys-select-values-and.html
January 6, 2011
by Jay Fields
· 15,759 Views
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Using Default Values for Properties in Spring
I was looking through the Spring Greenhouse application and discovered an existing feature that I was unaware of. We can set a default value when configuring PropertyPlaceholderConfigurer. 1. Set the default value separator in config <-- Ignore file not found --> <-- Ignore when tokens are not found --> ... 2. Set the default values for your properties ... Notes If unspecified, the default separator is a colon “:” This option is not available when using the “context” namespace – (submitted Jira ticket: SPR-7794) From http://gordondickens.com/wordpress/2010/12/06/using-default-values-for-properties-in-spring/
December 30, 2010
by Gordon Dickens
· 52,541 Views
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10 Effective Ways to Become a Good Programmer
A good programmer is someone who always looks both ways before crossing a one-way street. -Doug Linder
December 27, 2010
by Ashish Arya
· 204,875 Views · 11 Likes
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Domain Objects and Their Variants
I read "Domain Object Dependency Injection with Spring" the other day. Actually, what interested me were those comments about the concepts and patterns around "Domain Object". I had been always confused about those buzzwords related to Domain Object: Domain Object, Business Object, DTO, POJO, Anemic Domain Object, Active Record Pattern. After some research, I found several points critical to help understand those concepts (at least for myself): Among those concepts, POJO is not that relevant. It's a general principal applied to all enterprise beans (service beans, dao beans, etc.) not to be framework-specifc, though framework-specific annotations are commonly used in 'POJO' these days. Domain Object == Business Object. They are entity representitives in business layer, which shoud be understood by non-programming people, such as business analysts. Business Object should have both data and behaviour. Anemic Domain Object are those business objects only have data without behaviour. Data Transfer Object (DTO) is a concept within data access layer. DTOs are often used in conjunction with DAOs to represent data retrieved from a DB. DTOs and Domain Objects can be designed to use the same class, even represented by the same object for the same entity. Personally, I think Domain Objects refer to the combination of DTO and Business Objects for plenty of cases. Active Record Pattern: Domain objects have rich behaviour, for example, inject DAO into domain objects to make it has CRUD ability. Understanding the above concepts is just half way, I would like to going further for things behind these domain object variants: On the one hand, people like Martin Fowler thinks domain object should have data and behaviour, which is consistent with OOD. Anemic Domain Object is anti-pattern, which in effect causes 'procedure script' style thick service layer. On the other hand, anemic domain objects are still popular. For myself, the following two facts explain the phenomenon: Active Record Pattern is really painful. I don't like the idea of putting DAO into Domain Object at all. And the clear multi-layer design, makes coding more intuitive and very easy to maintain. Encapsulating behaviour into business object doesn't mean removing service layer at all. Just don't put all behaviour into service layer, this layer should be as thin as possible. What I learned: I will put behaviour only relevant to the individual entity into domain object, for example: validation, calculation, maybe CRUD (I still prefer having separate DAO to fufill the tasks, don't like any huge object) Service layer should serve as a gateway to all above layer, which means any business atomic operation should find its place in service layer. Then, transaction can be managed in one layer. Behaviour involves different entities regardless same type of entity or different types may go into service layer. This is my personal opinion based on what I understand so far. Any comments or critisim are welcome. PS. This is my first post:) Wish it good luck, and Merry Christmas to everyone. More to say: I've read the "Domain Driven Design" refcardz after writing this article, found out some similar points were already mentioned there, though DDD covers broad aspects. I think my article exposes some facts or problems of this topic, which would help people obtain deep insides via further reading. Actually, I am planning to read some DDD book as the second session after current looking up.
December 21, 2010
by Yaozong Zhu
· 29,212 Views · 3 Likes
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jQuery Templates – tmpl(), template() and tmplItem()
In the first blog, I made introduction to the jQuery Templates plugin made by Microsoft for the jQuery library. Now in this blog I will pass briefly through the three main functions that are supported by the plugin up to now. - tmpl() and $.tmpl() The purpose of this function is to render the template Syntax: tmpl([data], [options]) $.tmpl(template, [data], [options]) As you can see, the first tmpl() function takes two parameters, while the second takes three parameters. What is the real difference here? Both functions make the same. The difference is that in the second $.tmpl (with jQuery sign) we have template parameter so that this parameter can be string containing markup, HTML Element, or Name of named template. To see this in real-world example, see the complete example at the bottom of this blog. tmpl() Example $("#myTemplate").tmpl(myData).appendTo("ul"); $.tmpl() Example $.tmpl("namedTemplate", myData).appendTo("ul"); - template() and $.template() We can use this function to create named templates. Previously I’ve written an example with $.tmpl() where it’s first parameter is named template. We can create named templates using tempalte or $.template() and use it anywhere else. So, with this function we can simply compile the template by associating it with the given name. Syntax: template([name]) $.template(name, template) Let’s see two simple examples: template() Example $("#myTemplate").template("attendeeTemplate"); $.template() $.template("attendeeTemplate", "${Attendee}"); Usage of the above example would be $.tmpl("attendeeTemplate", Data).appendTo("ol") now you see both $.tmpl and $.template in same scenario - tmplItem() and $.tmplItem() Using this function, we can access the rendered template item. It will retrieve object which has data and nodes properties. Syntax: tmplItem() $.tmplItem(element) And here are the examples: tmplItem() var item = $("font").tmplItem(); $.tmplItem() var item = $.tmplItem("font"); Here is complete example where I’m using all three functions in one scenario Name: Surname: Speaker: Add New HighLight Last Speaker the result is You can simply copy the code and paste it in your VS.NET by creating new page and it will work fine. You don’t need to add scripts manually since I use the scripts directly from Microsoft CDN.
December 15, 2010
by Hajan Selmani
· 34,204 Views
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A simple and intuitive approach to interface your database with Java
Introduction In recent years, I have experienced the same developer's need again and again. The need for improved persistence support. After lots of years of experience with Java, I have grown tired with all the solutions that are "standard", "J2EE compliant", but in the end, just ever so complicated. I don't deny, there are many good ideas around, that have eventually brought up excellent tools, such as Hibernate, JPA/EJB3, iBatis, etc. But all of those tools seem to go to a single direction without giving up any of that thought: Object-relational Mapping. So you end up using a performant database that cost's 100k+$ of license every year just to abstract it with a "standard" persistence layer. I wanted to go a different direction. And take the best of OR-Mapping (code generation, type safety, object oriented query construction, SQL dialect abstraction, etc) without denying the fact, that beneath, I'm running an RDBMS. That's right. R like Relational. Read on about how jOOQ (Java Object Oriented Querying) succeeds in bringing the "relational to the object" Abstract Many companies and software projects seem to implement one of the following two approaches to interfacing Java with SQL The very basic approach: Using JDBC directly or adding a home-grown abstraction on top of it. There is a lot of manual work associated with the creation, maintenance, and extension of the data layer code base. Developers can easily use the full functionality of the underlying database, but will always operate on a very low level, concatenating Strings all over the place. The very sophisticated approach: There is a lot of configuration and a steep learning curve associated with the introduction of sophisticated database abstraction layers, such as the ones created by Hibernate, JPA, iBatis, or even plain old EJB entity beans. While the generated objects and API's may allow for easy manipulation of data, the setup and maintenance of the abstraction layer may become very complex. Besides, these abstraction layers provide so much abstraction on top of SQL, that SQL-experienced developers have to rethink. A different paradigm I tried to find a new solution addressing many issues that I think most developers face every day. With jOOQ - Java Object Oriented Querying, I want to embrace the following paradigm: SQL is a good thing. Many things can be expressed quite nicely in SQL. The relational data model is a good thing. It should not be abstracted by OR-Mapping SQL has a structure and syntax. It should not be expressed using "low-level" String concatenation. Variable binding tends to be very complex when dealing with major queries. POJO's (or data transfer objects) are great when writing Java code manipulating database data. POJO's are a pain to write and maintain manually. Source code generation is the way to go The database comes first. Then the code on top of it. Yes, you do have stored procedures and user defined types (UDT's) in your legacy database. Your database-tool should support that. I think that these key ideas are useful for a very specific type of developer. That specific developer interfaces Java with huge legacy databases. knows SQL well and wants to use it extensively. doesn't want to learn any new language (HQL, JPQL, etc) doesn't want to spend one minute fine-tuning some sophisticated XML-configuration. wants little abstraction over SQL, because his software is tightly coupled with his database. Something that I think the guys at Hibernate or JPA seem to have ignored. needs a strong but light-weight library for database access. For instance to develop for mobile devices. How does jOOQ fit in this paradigm? Not only does jOOQ completely address the above paradigm, it does so quite elegantly. Let's say you have this database that models your bookstore. And you need to run a query selecting all books by authors born after 1920. You know how to do this in SQL: -- Select all books by authors born after 1920, named "Paulo" from a catalogue: SELECT * FROM t_author a JOIN t_book b ON a.id = b.author_id WHERE a.year_of_birth > 1920 AND a.first_name = 'Paulo' ORDER BY b.title The same query expressed with jOOQ-Objects // Instanciate your factory using a JDBC connection // and specify the SQL dialect you're using. Of course you can // have several factories in your application. Factory create = new Factory(connection, SQLDialect.MYSQL); // Create the query using generated, type-safe objects. You could // write even less code than that with static imports! SelectQuery q = create.selectQuery(); q.addFrom(TAuthor.T_AUTHOR); q.addJoin(TBook.T_BOOK, TAuthor.ID, TBook.AUTHOR_ID); // Note how you do not need to worry about variable binding. // jOOQ does that for you, dynamically q.addCompareCondition(TAuthor.YEAR_OF_BIRTH, 1920, Comparator.GREATER); // The AND operator and EQUALS comparator are implicit here q.addCompareCondition(TAuthor.FIRST_NAME, "Paulo"); q.addOrderBy(TBook.TITLE); The jOOQ query object model uses generated classes, such as TAuthor or TBook. Like many other code generation tools do, jOOQ will generate static final objects for the fields contained in each table. In this case, TAuthor holds a member called TAuthor.T_AUTHOR to represent the table itself, and members such as TAuthor.ID, TAuthor.YEAR_OF_BIRTH, etc to hold the table's fields. But you could also use the jOOQ DSL API to stay closer to SQL // Do it all "on one line". SelectQuery q = create.select() .from(T_AUTHOR) .join(T_BOOK).on(TAuthor.ID.equal(TBook.AUTHOR_ID)) .where(TAuthor.YEAR_OF_BIRTH.greaterThan(1920) .and(TAuthor.FIRST_NAME.equal("Paulo"))) .orderBy(TBook.TITLE).getQuery(); jOOQ ships with a DSL (Domain Specific Language) somewhat similar to Linq that facilitates query creation. The strength of DSL becomes obvious when you are using jOOQ constructs such as the decode function: // Create a case statement. Unfortunately "case" is a reserved word in Java // Hence the method is called DECODE after its related Oracle function Field nationality = create.decode() .when(TAuthor.FIRST_NAME.equal("Paulo"), "brazilian") .when(TAuthor.FIRST_NAME.equal("George"), "english") .otherwise("unknown"); // "else" is also a reserved word ;-) The above will render this SQL code: CASE WHEN T_AUTHOR.FIRST_NAME = 'Paulo' THEN 'brazilian' WHEN T_AUTHOR.FIRST_NAME = 'George' THEN 'english' ELSE 'unknown' END Use the DSL API when: You want your Java code to look like SQL You want your IDE to help you with auto-completion (you will not be able to write select .. order by .. where .. join or any of that stuff) Use the regular API when: You want to create your query step-by-step, creating query parts one-by-one You need to assemble your query from various places, passing the query around, adding new conditions and joins on the way In any case, all API's will construct the same underlying implementation object, and in many cases, you can combine the two approaches Once you have established the query, execute it and fetch results // Execute the query and fetch the results q.execute(); Result result = q.getResult(); // Result is Iterable, so you can loop over the resulting records like this: for (Record record : result) { // Type safety assured with generics String firstName = record.getValue(TAuthor.FIRST_NAME); String lastName = record.getValue(TAuthor.LAST_NAME); String title = record.getValue(TBook.TITLE); Integer publishedIn = record.getValue(TBook.PUBLISHED_IN); System.out.println(title + " (published in " + publishedIn + ") by " + firstName + " " + lastName); } Or simply write for (Record record : q.fetch()) { // [...] } Fetch data from a single table and use jOOQ as a simple OR-Mapper // Similar query, but don't join books to authors. // Note the generic record type that is added to your query: SimpleSelectQuery q = create.select(T_AUTHOR) .where(TAuthor.YEAR_OF_BIRTH.greaterThan(1920) .and(TAuthor.FIRST_NAME.equal("Paulo"))) .orderBy(TAuthor.LAST_NAME).getQuery(); // When executing this query, also Result holds a generic type: q.execute(); Result result = q.getResult(); for (TAuthorRecord record : result) { // With generate record classes, you can use generated getters and setters: String firstName = record.getFirstName(); String lastName = record.getLastName(); System.out.println("Author : " + firstName + " " + lastName + " wrote : "); // Use generated foreign key navigation methods for (TBookRecord book : record.getTBooks()) { System.out.println(" Book : " + book.getTitle()); } } jOOQ not only generates code to model your schema, but it also generates domain model classes to represent tuples in your schema. In the above example, you can see how selecting from the TAuthor.T_AUTHOR table will produce results containing well-defined TAuthorRecord types. These types hold getters and setters like any POJO, but also some more advanced OR-code, such as foreign key navigator methods like // Return all books for an author that are obtained through the // T_AUTHOR.ID = T_BOOK.AUTHOR_ID foreign key relationship public List getTBooks() Now, for true OR-mapping, you would probably prefer mature and established frameworks such as Hibernate or iBATIS. Don't panic. Better integration with Hibernate and JPA is on the feature roadmap. The goals of jOOQ should not be to reimplement things that are already well-done, but to bring true SQL to Java Execute CRUD operations with jOOQ as an OR-mapper // Create a new record and insert it into the database TBookRecord book = create.newRecord(T_BOOK); book.setTitle("My first book"); book.store(); // Update it with new values book.setPublishedIn(2010); book.store(); // Delete it book.delete(); Nothing new in the OR-mapping world. These ideas have been around since EJB entity beans or even before. It's still quite useful for simple purposes. Execute CRUD operations the way you're used to You don't need to go into that OR-mapping business. You can create your own INSERT, "INSERT SELECT", UPDATE, DELETE queries. Some examples: InsertQuery i = create.insertQuery(T_AUTHOR); i.addValue(TAuthor.FIRST_NAME, "Hermann"); i.addValue(TAuthor.LAST_NAME, "Hesse"); i.execute(); UpdateQuery u = create.updateQuery(T_AUTHOR); u.addValue(TAuthor.FIRST_NAME, "Hermie"); u.addCompareCondition(TAuthor.LAST_NAME.equal("Hesse")); u.execute(); // etc... Now for the advanced stuff Many tools can do similar stuff as what we have seen before. Especially Hibernate and JPA have a feature called criteria query, that provides all of the type-safety and query object building using DSL's while being based on a solid (but blown-up) underlying architecture. An important goal for jOOQ is to provide you with all (or at least: most) SQL features that you are missing in other frameworks but that you would like to use because you think SQL is a great thing but JDBC is too primitive for the year 2010, 2011, or whatever year we're in, when you're reading this. So, jOOQ comes along with aliasing, nested selects, unions and many other SQL features. Check out the following sections: Aliasing That's a very important feature. How could you have self-joins or in/exists clauses without aliasing? Let's say we have a "T_TREE" table with fields "ID", "PARENT_ID", and "NAME". If we want to find all parent/child NAME couples, we will need to execute a self-join on T_TREE. In SQL, this reads: SELECT parent.NAME parent_name, child.NAME child_name FROM T_TREE parent JOIN T_TREE child ON (parent.ID = child.PARENT_ID) No problem for jOOQ. We'll write: // Create table aliases Table parent = TTree.T_TREE.as("parent"); Table child = TTree.T_TREE.as("child"); // Create field aliases from aliased table Field parentName = parent.getField(TTree.NAME).as("parent_name"); Field childName = child.getField(TTree.NAME).as("child_name"); // Execute the above select Record record = create.select(parentName, childName) .from(parent) .join(child).on(parent.getField(TTree.ID).equal(child.getField(TTree.PARENT_ID))) .fetchAny(); // The aliased fields can be read from the record as in the simpler examples: record.getValue(parentName); Functionally, it is easy to see how this works. Look out for future releases of jOOQ for improvements in the DSL support of field and table aliasing IN clause The org.jooq.Field class provides many methods to construct conditions. In previous examples, we have seen how to create regular compare conditions with = < <= >= > != operators. Now Field also has a couple of methods to create IN conditions: // Create IN conditions with constant values that are bound to the // query via JDBC's '?' bind variable placeholders Condition in(T... values); Condition in(Collection values); Condition notIn(T... values); Condition notIn(Collection values); // Create IN conditions with a sub-select Condition in(QueryProvider query) Condition notIn(QueryProvider query) The constant set of values for IN conditions is an obvious feature. But the sub-select is quite nice: -- Select authors with books that are sold out SELECT * FROM T_AUTHOR WHERE T_AUTHOR.ID IN (SELECT DISTINCT T_BOOK.AUTHOR_ID FROM T_BOOK WHERE T_BOOK.STATUS = 'SOLD OUT'); In jOOQ, this translates to create.select(T_AUTHOR) .where (TAuthor.ID.in(create.selectDistinct(TBook.AUTHOR_ID) .from(T_BOOK) .where(TBook.STATUS.equal(TBookStatus.SOLD_OUT)))); EXISTS clause Very similar statements can be expressed with the EXISTS clause. The above set of authors could also be obtained with this statement: -- Select authors with books that are sold out SELECT * FROM T_AUTHOR a WHERE EXISTS (SELECT 1 FROM T_BOOK WHERE T_BOOK.STATUS = 'SOLD OUT' AND T_BOOK.AUTHOR_ID = a.ID); In jOOQ (as of version 1.5.0), this translates to // Alias the author table Table a = T_AUTHOR.as("a"); // Use the aliased table in the select statement create.selectFrom(a) .where(create.exists(create.select(create.constant(1)) .from(T_BOOK) .where(TBook.STATUS.equal(TBookStatus.SOLD_OUT) .and(TBook.AUTHOR_ID.equal(a.getField(TAuthor.ID)))))); UNION clauses SQL knows of four types of "UNION operators": UNION UNION ALL EXCEPT INTERSECT All of these operators are supported by all types of select queries. So in order to write things like: SELECT TITLE FROM T_BOOK WHERE PUBLISHED_IN > 1945 UNION SELECT TITLE FROM T_BOOK WHERE AUTHOR_ID = 1 You can write the following jOOQ logic: create.select(TBook.TITLE).from(T_BOOK).where(TBook.PUBLISHED_IN.greaterThan(1945)).union( create.select(TBook.TITLE).from(T_BOOK).where(TBook.AUTHOR_ID.equal(1))); Of course, you can then again nest the union query in another one (but be careful to correctly use aliases): -- alias_38173 is an example of a generated alias, -- generated by jOOQ for union queries SELECT alias_38173.TITLE FROM ( SELECT T_BOOK.TITLE, T_BOOK.AUTHOR_ID FROM T_BOOK WHERE T_BOOK.PUBLISHED_IN > 1945 UNION SELECT T_BOOK.TITLE, T_BOOK.AUTHOR_ID FROM T_BOOK WHERE T_BOOK.AUTHOR_ID = 1 ) alias_38173 ORDER BY alias_38173.AUTHOR_ID DESC In jOOQ: Select union = create.select(TBook.TITLE, TBook.AUTHOR_ID).from(T_BOOK).where(TBook.PUBLISHED_IN.greaterThan(1945)).union( create.select(TBook.TITLE, TBook.AUTHOR_ID).from(T_BOOK).where(TBook.AUTHOR_ID.equal(1))); create.select(union.getField(TBook.TITLE)) .from(union) .orderBy(union.getField(TBook.AUTHOR_ID).descending()); Note that a UNION query will automatically generate an alias if you use it as a nested table. In order to nest this query correctly, you need to get the aliased field from the query as seen in the example abov. Other, non-standard SQL features See more examples about stored procedures, UDT's, enums, etc on https://sourceforge.net/apps/trac/jooq/wiki/Examples Summary jOOQ brings the relational world to Java without trying to cover up its origins. jOOQ is relational. And object oriented. Just in a different way. Try it for yourself and I would be very glad for any feedback you may have. Find jOOQ on http://jooq.sourceforge.net Cheers Lukas Eder
December 14, 2010
by Lukas Eder
· 3,933 Views
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Getting MySQL work with Entity Framework 4.0
Does MySQL work with Entity Framework 4.0? The answer is: yes, it works! I just put up one experimental project to play with MySQL and Entity Framework 4.0 and in this posting I will show you how to get MySQL data to EF. Also I will give some suggestions how to deploy your applications to hosting and cloud environments. MySQL stuff As you may guess you need MySQL running somewhere. I have MySQL installed to my development machine so I can also develop stuff when I’m offline. The other thing you need is MySQL Connector for .NET Framework. Currently there is available development version of MySQL Connector/NET 6.3.5 that supports Visual Studio 2010. Before you start download MySQL and Connector/NET: MySQL Community Server Connector/NET 6.3.5 If you are not big fan of phpMyAdmin then you can try out free desktop client for MySQL – HeidiSQL. I am using it and I am really happy with this program. NB! If you just put up MySQL then create also database with couple of table there. To use all features of Entity Framework 4.0 I suggest you to use InnoDB or other engine that has support for foreign keys. Connecting MySQL to Entity Framework 4.0 Now create simple console project using Visual Studio 2010 and go through the following steps. 1. Add new ADO.NET Entity Data Model to your project. For model insert the name that is informative and that you are able later recognize. Now you can choose how you want to create your model. Select “Generate from database” and click OK. 2. Set up database connection Change data connection and select MySQL Database as data source. You may also need to set provider – there is only one choice. Select it if data provider combo shows empty value. Click OK and insert connection information you are asked about. Don’t forget to click test connection button to see if your connection data is okay. If everything works then click OK. 3. Insert context name Now you should see the following dialog. Insert your data model name for application configuration file and click OK. Click next button. 4. Select tables for model Now you can select tables and views your classes are based on. I have small database with events data. Uncheck the checkbox “Include foreign key columns in the model” – it is damn annoying to get them away from model later. Also insert informative and easy to remember name for your model. Click finish button. 5. Define your classes Now it’s time to define your classes. Here you can see what Entity Framework generated for you. Relations were detected automatically – that’s why we needed foreign keys. The names of classes and their members are not nice yet. After some modifications my class model looks like on the following diagram. Note that I removed attendees navigation property from person class. Now my classes look nice and they follow conventions I am using when naming classes and their members. NB! Don’t forget to see properties of classes (properties windows) and modify their set names if set names contain numbers (I changed set name for Entity from Entity1 to Entities). 6. Let’s test! Now let’s write simple testing program to see if MySQL data runs through Entity Framework 4.0 as expected. My program looks for events where I attended. using(var context = new MySqlEntities()) { var myEvents = from e in context.Events from a in e.Attendees where a.Person.FirstName == "Gunnar" && a.Person.LastName == "Peipman" select e; Console.WriteLine("My events: "); foreach(var e in myEvents) { Console.WriteLine(e.Title); } } Console.ReadKey(); And when I run it I get the result shown on screenshot on right. I checked out from database and these results are correct. At first run connector seems to work slow but this is only the effect of first run. As connector is loaded to memory by Entity Framework it works fast from this point on. Now let’s see what we have to do to get our program work in hosting and cloud environments where MySQL connector is not installed. Deploying application to hosting and cloud environments If your hosting or cloud environment has no MySQL connector installed you have to provide MySQL connector assemblies with your project. Add the following assemblies to your project’s bin folder and include them to your project (otherwise they are not packaged by WebDeploy and Azure tools): MySQL.Data MySQL.Data.Entity MySQL.Web You can also add references to these assemblies and mark references as local so these assemblies are copied to binary folder of your application. If you have references to these assemblies then you don’t have to include them to your project from bin folder. Also add the following block to your application configuration file. ... ... Conclusion It was not hard to get MySQL connector installed and MySQL connected to Entity Framework 4.0. To use full power of Entity Framework we used InnoDB engine because it supports foreign keys. It was also easy to query our model. To get our project online we needed some easy modifications to our project and configuration files.
December 10, 2010
by Gunnar Peipman
· 24,582 Views
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Changing Eclipse Default Encoding to UTF-8 for JSP files
Try creating a new JSP file in your Eclipse and you’ll notice that the JSP page directive will have encoding something like: But for a better I18N and L10N support, it is recommended to follow UTF-8 encoding where ever possible. So, how do we change the default JSP file encoding to UTF-8 in eclipse? Simple. Just do these things: In Eclipse, go to Windows -> Preferences -> Web -> JSP Files Select UTF-8 encoding from the Encoding dropdown box there. That’s it! And if you wonder how this change works, you can very well see that. In the same Preferences window, go to this location: Preferences -> Web -> JSP Files -> Editor -> Templates. Then in the right hand side, you’ll see a list of templates defined for JSP files. And in a new JSP file template, you can see this code: Here as you might have guessed, the ${encoding} will be replaced by whatever we set in the above step. The same method can be used to change the default encoding type for other file types too (css, html). From http://veerasundar.com/blog/2010/12/changing-eclipse-default-encoding-to-utf-8-for-jsp-files/
December 8, 2010
by Veera Sundar
· 26,679 Views · 1 Like
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The Domain Model as REST Anti-pattern
Today JavaLobby published yet anotherdomain-model-as-RESTarticle, using Spring and Jersey. As already pointed out, this really is an anti-pattern, and is not RESTful, and cannot be so either. The point that all of these types of articles miss is theHATEOASpart, the hyperlinking of resources. If you expose your domain model, basically saying "here's all I got, use as you see fit", there is no sensible way to create links between resources that expose the application state. There is no sensible way to tell the client "here's what you can do next", because the "REST" API allows anything at any time. Here's an example, from my own app, which showed me the problem with this approach. I have users in my system. I need two ways to work with their passwords: the user must be allowed to change his own password, and the administrator shall be allowed to reset any users' password. In the beginning, when I was exposing my domain model, the URL's for this were as follows: /user//changepassword/user//resetpassword I'm just doing what the article suggests, which is to expose my domain model, and all that I can do with it. What's the problem with this? The first and most obvious problem is that it's very hard to determine who is allowed to do what here. I need to have authorization checks on both "changepassword" and "resetpassword". The first needs to check if it is the same user that accesses it, and the second needs to check if the accessing user has the administrator role. Also, since the client MUST get to these resources by following links in hypermedia (that's a constraint, remember?), the most obvious thing to do is to list them when accessing /user//. But then my link lists need to do these authorization checks as well, because if the user is not an administrator, then the "resetpassword" link should not be there. I should not allow clients to see links they cannot reasonably follow! My UI will also be quite complicated, because in one screen I might do "resetpassword" and a number of other administrative tasks, each of which uses different parts of the domain model, and so its exposure to the API, and consequently, its brittleness if the API changes, is immense. It's just a very bad situation, and one which you'll get into by following the guidelines in all of these expose-your-domain-model articles. So what to do instead? The trick is to expose usecases instead. It's that simple. Now, the main problem with doing this is that you have to actually know what your usecases are! And this is probably why all of these articles do the domain-model anti-pattern: because of their simplified nature they only thought to the point of "we gotta have users in our system" and not take the next step "what can we do with them?", because then you need to decide a whole lot more about what your system does. Since articles need to be reasonably focused on one thing, they just don't go there. But for You, if you do that, you end up with the mess outlined above. What did we do in our REST API to fix the above? We simply looked at our usecases, and rearranged the REST API accordingly. For the above, they relate to two different usecases which are account handling and user administration. And so we changed the API to something like this: /account/changepassword/administration/users//resetpassword If a client goes to /account/, which it can do by first going to "/" and finding that link, it will receive a list of links with what you can do on your own account, such as "changepassword". Do a GET on that link, and the client gets a form with two fields: the old password and the new password. The client might show this as three fields though, with a duplicate new password field to ensure that the user typed it correctly. The client can then POST to "changepassword" to make the actual change. I don't have to make any authorization checks, since the client is implicitly accessing its own account, so there's no way to screw it up, even deliberately. For the admin side, the client browses to /administration/users/ (and again, that link was retrieved from "/" if the user is an administrator), lists/searches the users, gets the link to a particular user, do a GET on "resetpassword" to get the form for it, and then fills it in and POST it to make the change. The REST API has at all times told the client what it is allowed to do, by using hypertext to drive the application state. This is what HATEOAS means in practice, and it is VERY helpful if you expose your usecases, and VERY annoying if you expose your domain model (simply because you can't). This approach also removes the issue outlined in the article with circular references, simply because in usecases, there are no circular references. Another effect of this is that links in the REST API will almost always be relative, since all they do is guide the client further into a usecase, or sub-usecase. If you expose domain models you have to have absolute links, and they will be going here there and everywhere, exposing the internal associations between entities. It's stupid beyond belief, but this is what pretty much all of the current articles on "RESTful" frameworks tell you to do. And I say: DON'T! It'll only bring you misery. From a security point of view the above is also easier to work with. Now all I have to do is add a check on "/administration/" for the administrator role, and after that the user can do anything below that point. No need to duplicate that check everywhere (and no need to use aspects to get around this annoyance)! Now that you know what to do, the next question might be: how to do it? The problem here is that since all the current "REST" frameworks haven't thought HATEOAS through, they don't really allow you to make REST API's for your applications, and so, they will not be very easy to use. You have to work against them. This goes for Jersey and friends as well, as they don't allow this usecase approach to URL parsing. What we have done in my project, Streamflow, is to create our own wrapper on top ofRestlet. Restlet provides an excellent base for REST applications, but is too low-level to have to deal with in the application code. By putting a thin wrapper on top of it, which understand the notion of usecases and links, we have been able to really reduce the amount of code needed to do all of this. Here's sample code for "change password". The code uses a routing technique, so in order to get to /account/changepassword, the framework first takes "/" and finds a resource for that. This resource then knows how to get to "/account/", which in turn knows how to get to "changepassword". The code looks like this: public class RootResource extends CommandQueryResource{ @SubResource public void account() { subResource( AccountResource.class ); }...} When the client hits "/" the framework will automatically look at this class, and present hypermedia (JSON or HTML at this point, but Atom Services is also an option) for it. The client clicks "/account/", which leads to this: public class AccountResource extends CommandQueryResource{ public AccountResource( ) { super( AccountContext.class ); } @SubResource public void profile() { subResourceContexts( ProfileContext.class, ContactableContext.class ); } To find out what the client can do on this level you look in AccountContext. If you want to continue further down into the profile handling of an account (setting email, phone, etc.) the client would follow "/account/profile/" link that is presented. In our case, let's look at AccountContext: public class AccountContext{ public void changepassword( ChangePasswordCommand newPassword ) throws WrongPasswordException { UserAuthentication user = RoleMap.role( UserAuthentication.class ); user.changePassword( newPassword.oldPassword().get(), newPassword .newPassword().get() ); } It exposes one interaction on this level of the usecase, which is /account/changepassword. The parameter tells the framwork what it requires as input, so if the client does GET it can look at the ChangePasswordCommand value object and present it as a form. If the client does a POST the framework parses the input into the value object and invokes the method, allowing it to "do it's thing". In this case it looks up the UserAuthentication role, which is a Qi4j mixin that our user entity implements. This entity was registered automatically by the authentication filter, so I don't have to look it up. For the administration usecase the code would get access to the "" part of the URL so that it can locate the user from the repository. And that's pretty much it. Not only is this easier to work with for clients (who simply follow links in hypermedia), but the code in both client and application is also absolutely trivial. I can also find out what my REST API looks like in total by starting with RootResource and explore the API by clicking on the classes it references. Since the API is so deterministic given these classes I can also generate documentation automatically that basically says, "given your user authorization level, here are all the resources you can access in the API". In particular, when your API becomes hypermedia driven like this, what you want to expose as documentation is the set of "rel" attributes that the client must know, in this case "account" and "changepassword". What the URL's look like is none of the clients business! It should just go to "/" and follow links based on the "rel" attribute of those links. Then you can say that your API is "RESTful". Until you do that, no, you may have a "web API" or a "HTTP API", but it aint REST. There are more details in how this works, and how to turn links on/off depending on internal state, but the gist of how to think is as above. From http://www.jroller.com/rickard/entry/the_domain_model_as_rest
December 8, 2010
by Rickard Oberg
· 32,020 Views · 2 Likes
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Using Sphinx and Java to Implement Free Text Search
As promised I am going to provide an article on how we can use Sphinx with Java to perform a full text search. I will begin the article with an introduction to Sphinx. Introduction to Sphinx Databases are continually growing and sometimes tend to hold about 100M records and need an external solution for full text search to be performed. I have picked Sphinx, an open source full-text search engine, distributed under GPL version 2 to perform a full text search on such a huge amount of data. Generally, it's a standalone search engine meant to provide fast, size-efficient and relevant full-text search functions to other applications very much compatible with an SQL Database. So my example will be based on the MySQL database, as we cannot produce millions of data to evaluate the real power of Sphinx, we will have a small amount of data and I think that should not be a problem. Here are few Sphinx Unique Features: high indexing speed (up to 10 MB/sec on modern CPUs) high search speed (avg query is under 0.1 sec on 2-4 GB text collections) high scalability (up to 100 GB of text, upto 100 M documents on a single CPU) provides distributed searching capabilities provides searching from within MySQL through pluggable storage engine supports boolean, phrase, and word proximity queries supports multiple full-text fields per document (upto 32 by default) supports multiple additional attributes per document (ie. groups, timestamps, etc) supports MySQL natively (MyISAM and InnoDB tables are both supported) The important features which have been adopted to perform a full text search are the provision of the Java API to integrate easily with the web application and considerably high indexing and searching speed with an average of 4-10 MB/sec & 20-30 ms/q @5GB,3.5M docs(wikipedia) Sphinx Terms & How It Works The fist principle part of sphinx is indexer. It is solely responsible for gathering the data that will be searchable. From the Sphinx point of view, the data it indexes is a set of structured documents, each of which has the same set of fields. This is biased towards SQL, where each row corresponds to a document, and each column to a field. Sphinx builds a special data structure optimized for our queries from the data provided. This structure is called index; and the process of building index from data is called indexing and the element of sphinx which carries out these tasks is called indexer. Indexer can be executed either from a regular script or command-line interface. Sphinx documents are equal to records in DB. Document is set of text fields and number attributes + unique ID – similar to row in DB Set of fields and attributes is constant for index – similar to table in DB Fields are searchable for FullText queries Attributes may be used for filtering, sorting, grouping searchd is the second principle tools as part of Sphinx. It is the part of the system which actually handles searches; it functions as a server and is responsible for receiving queries, processing them and returning a dataset back to the different APIs for client applications. Unlike indexer, searchd is not designed to be run either from a regular script or command-line calling, but instead either as a daemon to be called from init.d (on Unix/Linux type systems) or to be called as a service (on Windows-type systems). I am going to focus on Windows environment so later I will show you how we can install sphinx on windows as a service. Finally search is one of the helper tools within the Sphinx package. Whereas searchd is responsible for searches in a server-type environment, search is aimed at testing the index quickly without building a framework to make the connection to the server and process its response. This will only be used for testing sphinx from command – line and with respect to application’s requirement; searchd service will be used to query the MySql Server with a pre created index. Installation on Windows So now we come to the part of installing Sphinx on Windows: Download Sphinx from the official Sphinx download site i.e http://sphinxsearch.com (I downloaded Win32 release binaries with MySQL support: sphinx-0.9.9-win32.zip) Unzip the file to some folder, I unzipped to C:\devel\sphinx-0.9.9-win32 and added the bin directory to the windows path variable Well Sphinx is installed. Nice, simple, easy. Later I will tell how to set up indexes and search. Sample Application Till now I guess the whole motto of this article is clear to you, let's move ahead to define our sample application. We all use the Address Book to search for people by using their name or e-mail address when we want to immediately address an e-mail message to a specific person, people, or distribution list. We also search for people by using other basic information, such as e-mail alias, office location, and telephone number etc. I think most of the people on this planet are quire familiar with this kind of search, so let's make outlook address book as our sample database schema. Most of the fields are mapped from microsoft outlook, the only additional column is date of joining so that we can filter our queries based on joining dates of the employees. The example that I am going to put forth will use Sphinx to search for a particluar address entry using free text search, meaning the user is free to type in anything, here is our search screen, the DOJ (date of joining) search parameter is optional. The screen is self explanatory, let's move ahead and define our database. As Sphinx works well with MySQL and MySQL being free also, lets create our db scripts around mysql database (Those who wish to install MySQL can dowload it from http://www.mysql.com) Let's create our sample database 'addressbook' mysql> create database addressbook; Query OK, 1 row affected (0.03 sec) mysql> use addressbook; Database changed Note: The fields defined in the following tables are for the purpose of learning only and may not contain a complete set of fields that microsoft address book or any similar software may provide. mysql> CREATE TABLE addressbook ( Id int(11) NOT NULL, FirstName varchar(30) NOT NULL, LastName varchar(30) NOT NULL, OfficeId int(11) DEFAULT NULL, Title varchar(20) DEFAULT NULL, Alias varchar(20) NOT NULL, Email varchar(50) NOT NULL, DOJ date NOT NULL, PhoneNo varchar(20) DEFAULT NULL ) ENGINE=InnoDB DEFAULT CHARSET=utf8; mysql> CREATE TABLE CompanyLocations ( Id int(11) NOT NULL, Location varchar(60) NOT NULL, Country varchar(20) NOT NULL ) ENGINE=InnoDB DEFAULT CHARSET=utf8; It's time to put some dummy data into the table, so let's fill our tables. Our virtual company 'gogs.it' has six offices across India and Singapore as defined in the following insert script. mysql> insert into CompanyLocations (Id, Location, Country) VALUES (1, 'Tower One, Harbour Front, Singapore', 'SG'); insert into CompanyLocations (Id, Location, Country) VALUES (2, 'DLF Phase 3, Gurgaon, India', 'IN'); insert into CompanyLocations (Id, Location, Country) VALUES (3, 'Hiranandani Gardens, Powai, Mumbai, India', 'IN'); insert into CompanyLocations (Id, Location, Country) VALUES (4, 'Hinjwadi, Pune, India', 'IN'); insert into CompanyLocations (Id, Location, Country) VALUES (5, 'Toll Post, Nagrota, Jammu, India', 'IN'); insert into CompanyLocations (Id, Location, Country) VALUES (6, 'Bani (Kathua), India', 'IN'); Now comes the real stuff... The data sphinx is going to index, let's populate that as well...wooooo mysql> INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (1,'Aabheer','Kumar',1,'Mr','u534','[email protected]','2008-9-3', '+911234599990'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (2,'Aadarsh','Gupta',6,'Mr','u668','[email protected]','2007-2-23','+911234599991'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (3,'Aachman','Singh',5,'Mr','u2766','[email protected]','2006-12-18','+911234599992'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (4,'Aadesh','Shrivastav',5,'Mr','u3198','[email protected]','2007-11-23','+911234599993'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (5,'Aadi','manav',1,'Mr','u2686','[email protected]','2010-7-20','+911234599994'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (6,'Aadidev','singh',4,'Mr','u572','[email protected]','2010-8-18','+911234599995'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (7,'Aafreen','sheikh',4,'Smt','u1092','[email protected]','2007-7-11','+911234599996'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (8,'Aakar','Sherpa',5,'Mr','u1420','[email protected]','2009-10-3','+911234599997'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (9,'Aakash','Singh',4,'Mrs','u2884','[email protected]','2008-6-11','+911234599998'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (10,'Aalap','Singhania',4,'Mrs','u609','[email protected]','2010-10-8','+911234599999'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (11,'Aandaleeb','mahajan',1,'Smt','u131','[email protected]','2010-10-21','+911234580001'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (12,'Mamata','kumari',5,'Sh','u2519','[email protected]','2009-6-12','+911234580002'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (13,'Mamta','sharma',6,'Smt','u4123','[email protected]','2009-2-8','+911234580003'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (14,'Manali','singh',6,'Mr','u1078','[email protected]','2008-6-14','+911234580004'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (15,'Manda','saxena',1,'Mrs','u196','[email protected]','2010-9-4','+911234580005'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (16,'Salila','shetty',3,'Miss','u157','[email protected]','2009-11-15','+911234580006'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (17,'Salima','happy',3,'Mrs','u3445','[email protected]','2006-7-14','+911234580007'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (18,'Salma','haik',5,'Sh','u4621','[email protected]','2008-6-23','+911234580008'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (19,'Samita','patil',3,'Smt','u3156','[email protected]','2006-6-7','+911234580009'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (20,'Sameena','sheikh',5,'Mrs','u952','[email protected]','2008-8-13','+911234580010'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (21,'Ranita','gupta',5,'Mrs','u2664','[email protected]','2008-10-20','+911234580011'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (22,'Ranjana','sharma',1,'Sh','u3085','[email protected]','2010-6-21','+911234580012'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (23,'Ranjini','singh',6,'Mrs','u4200','[email protected]','2007-4-13','+911234580013'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (24,'Ranjita','vyapari',2,'Smt','u1109','[email protected]','2008-1-22','+911234580014'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (25,'Rashi','gupta',6,'Mrs','u3492','[email protected]','2006-2-2','+911234580015'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (26,'Rashmi','sehgal',3,'Mr','u3248','[email protected]','2008-9-9','+911234580016'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (27,'Rashmika','sexy',1,'Mrs','u4599','[email protected]','2009-3-12','+911234580017'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (28,'Rasika','dulari',3,'Smt','u2089','[email protected]','2009-1-24','+911234580018'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (29,'Dilber','lover',6,'Mr','u4241','[email protected]','2007-10-11','+911234580019'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (30,'Dilshad','happy',1,'Mr','u1564','[email protected]','2007-4-8','+911234580020'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (31,'Dipali','lights',5,'Sh','u1127','[email protected]','2006-11-1','+911234580021'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (32,'Dipika','lamp',1,'Sh','u2271','[email protected]','2010-12-17','+911234580022'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (33,'Dipti','brightness',5,'Smt','u422','[email protected]','2010-9-25','+911234580023'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (34,'Disha','singh',3,'Sh','u4604','[email protected]','2006-5-2','+911234580024'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (35,'Maadhav','Krishna',1,'Miss','u2561','[email protected]','2007-11-6','+911234580025'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (36,'Maagh','month',5,'Miss','u874','[email protected]','2008-5-8','+911234580026'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (37,'Maahir','Skilled',4,'Mr','u3372','[email protected]','2007-8-4','+911234580027'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (38,'Maalolan','Ahobilam',5,'Mrs','u3498','[email protected]','2007-7-9','+911234580028'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (39,'Maandhata','King',1,'Smt','u2089','[email protected]','2009-9-3','+911234580029'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (40,'Maaran','Brave',2,'Miss','u4020','[email protected]','2008-4-5','+9112345606001'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (41,'Maari','Rain',2,'Sh','u3593','[email protected]','2007-12-5','+9112345606002'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (42,'Madan','Cupid',4,'Mrs','u795','[email protected]','2007-11-11','+9112345606003'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (43,'Madangopal','Krishna',3,'Sh','u438','[email protected]','2007-2-19','+9112345606004'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (44,'sahil','gogna',1,'Sh','u2273','[email protected]','2007-10-7','+9112345606005'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (45,'nikhil','gogna',2,'Mr','u1240','[email protected]','2009-9-14','+9112345606006'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (46,'amit','gogna',5,'Sh','u3879','[email protected]','2006-2-8','+9112345606007'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (47,'krishan','gogna',4,'Miss','u3632','[email protected]','2010-9-20','+9112345606008'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (48,'anil','kashyap',4,'Smt','u3939','[email protected]','2010-3-15','+9112345606009'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (49,'sunil','kashyap',5,'Mrs','u3493','[email protected]','2008-3-16','+9112345606010'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (50,'sandy','singh',6,'Mrs','u4691','[email protected]','2009-6-2','+9112345606011'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (51,'vishal','kapoor',3,'Mr','u1087','[email protected]','2010-5-13','+9112345606012'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (52,'bala','ji',5,'Mrs','u4762','[email protected]','2007-8-9','+9112345606013'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (53,'karan','sarin',4,'Miss','u3030','[email protected]','2008-4-8','+9112345606014'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (54,'abhishek','kumar',4,'Miss','u1093','[email protected]','2008-12-21','+9112345605001'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (55,'babu','the',1,'Miss','u1055','[email protected]','2008-7-2','+9112345506001'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (56,'sandeep','gainda',3,'Miss','u1320','[email protected]','2010-5-14','+9112345606301'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (57,'dheeraj','kumar',3,'Miss','u3685','[email protected]','2007-10-14','+9112345606091'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (58,'dharmendra','chauhan',1,'Smt','u3235','[email protected]','2008-8-1','+9112345806001'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (59,'max','alan',3,'Smt','u3465','[email protected]','2009-5-5','+9112345608011'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (60,'hidayat','khan',3,'Smt','u958','[email protected]','2007-11-18','+911234599101'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (61,'himnashu','singh',4,'Miss','u2027','[email protected]','2008-3-2','+911234599102'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (62,'dinesh','kumar',6,'Sh','u3233','[email protected]','2008-5-9','+911234599103'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (63,'toshi','prakash',1,'Mr','u3766','[email protected]','2010-9-17','+911234599104'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (64,'niti','puri',3,'Mr','u3575','[email protected]','2009-11-15','+911234599105'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (65,'pawan','tikki',3,'Sh','u3919','[email protected]','2006-3-19','+911234599106'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (66,'gaurav','sharma',2,'Sh','u413','[email protected]','2010-4-2','+911234599107'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (67,'himanshu','verma',2,'Mrs','u4732','[email protected]','2009-3-20','+911234599108'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (68,'priyanshu','verma',3,'Sh','u183','[email protected]','2010-8-12','+911234599109'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (69,'nitika','luthra',2,'Mrs','u4259','[email protected]','2010-7-12','+911234599110'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (70,'neeru','gogna',2,'Sh','u1633','[email protected]','2010-6-23','+91532110000'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (71,'bindu','gupta',1,'Sh','u1859','[email protected]','2006-11-10','+91532110001'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (72,'gurleen','bakshi',5,'Miss','u1423','[email protected]','2007-7-1','+91532110003'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (73,'rahul','gupta',3,'Sh','u1223','[email protected]','2009-8-11','+91532110004'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (74,'jagdish','salgotra',3,'Mr','u12','[email protected]','2008-5-19','+91532110005'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (75,'vikas','sharma',3,'Smt','u465','[email protected]','2006-6-2','+91532110006'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (76,'poonam','mahendra',2,'Sh','u1744','[email protected]','2009-12-2','+91532110007'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (77,'pooja','kulkarni',3,'Mrs','u1903','[email protected]','2008-10-6','+91532110008'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (78,'priya','mahajan',6,'Sh','u4205','[email protected]','2010-8-5','+91532110009'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (79,'manoj','zerger',1,'Mrs','u3369','[email protected]','2009-12-4','+91532110010'); INSERT INTO AddressBook(Id, FirstName, LastName, OfficeId, Title, Alias, Email, DOJ, PhoneNo) VALUES (80,'mohan','master',5,'Mr','u2841','[email protected]','2010-10-7','+91532110011'); Please note that above employee data is just a data *only data* I created using a small java programme using random number generators and reading some names file, so you may find titles getting messed up :( We next create a procedure that we will use from java to fetch records that we just inserted. DROP PROCEDURE IF EXISTS search_address_book; CREATE PROCEDURE search_address_book(IN address_ids VARCHAR(1000) ) BEGIN DECLARE search_address_query VARCHAR(2000) DEFAULT ''; SET address_ids = CONCAT('\'', REPLACE(address_ids, ',', '\',\''), '\''); SET search_address_query = CONCAT(search_address_query, ' select ab.Id as Id , ab.FirstName as FName, ab.LastName as LName, cl.Location as Location, ab.Title as Title, ab.Alias as Alias, ab.Email as Email, ab.DOJ as DOJ, ab.PhoneNo as PhoneNo ' ); SET search_address_query = CONCAT(search_address_query, ' from AddressBook ab left join CompanyLocations cl on ab.OfficeId=cl.Id '); SET search_address_query = CONCAT(search_address_query, ' where ab.id IN (', address_ids ,') '); SET @statement = search_address_query; PREPARE dynquery FROM @statement; EXECUTE dynquery; DEALLOCATE PREPARE dynquery; END; # To get records for ids 1, 6 and 7, we run following commands: call search_address_book('1,6,7'); Configuring Sphinx It turns out that it was not terribly difficult to setup sphinx, but I had a hard time finding instructions on the web, so I'll post my steps here. By default Sphinx looks for 'sphinx.co.in' configuration file to come with indexes and other stuff, lets create and define source and index for our sample application addressbook.conf (read between the lines) ############################################################################# ## data source definition ############################################################################# source addressBookSource { ## SQL settings for 'mysql' ## type = mysql # some straightforward parameters for SQL source types sql_host = localhost sql_user = root sql_pass = root sql_db = addressbook sql_port = 3306 # optional, default is 3306 # pre-query, executed before the main fetch query sql_query_pre = SET NAMES utf8 # main document fetch query, integer document ID field MUST be the first selected column sql_query = \ select ab.Id as Id , ab.FirstName as FName, ab.LastName as LName, cl.Location as Location, \ ab.Title as Title, ab.Alias as Alias, ab.Email as Email, UNIX_TIMESTAMP(ab.DOJ) as DOJ, ab.PhoneNo as PhoneNo \ from AddressBook ab left join CompanyLocations cl on ab.OfficeId=cl.Id sql_attr_timestamp = DOJ # document info query, ONLY for CLI search (ie. testing and debugging) , optional, default is empty must contain $id macro and must fetch the document by that id sql_query_info = SELECT * FROM AddressBook WHERE id=$id } ############################################################################# ## index definition ############################################################################# # local index example, this is an index which is stored locally in the filesystem index addressBookIndex { # document source(s) to index source = addressBookSource # index files path and file name, without extension, make sure you have this folder path = C:\devel\sphinx-0.9.9-win32\data\addressBookIndex # document attribute values (docinfo) storage mode docinfo = extern # memory locking for cached data (.spa and .spi), to prevent swapping mlock = 0 morphology = none # make sure this file exists exceptions =C:\devel\sphinx-0.9.9-win32\data\exceptions.txt enable_star = 1 } ############################################################################# ## indexer settings ############################################################################# indexer { # memory limit, in bytes, kiloytes (16384K) or megabytes (256M) # optional, default is 32M, max is 2047M, recommended is 256M to 1024M mem_limit = 32M # maximum IO calls per second (for I/O throttling) # optional, default is 0 (unlimited) # # max_iops = 40 # maximum IO call size, bytes (for I/O throttling) # optional, default is 0 (unlimited) # # max_iosize = 1048576 # maximum xmlpipe2 field length, bytes # optional, default is 2M # # max_xmlpipe2_field = 4M # write buffer size, bytes # several (currently up to 4) buffers will be allocated # write buffers are allocated in addition to mem_limit # optional, default is 1M # # write_buffer = 1M } ############################################################################# ## searchd settings ############################################################################# searchd { # hostname, port, or hostname:port, or /unix/socket/path to listen on listen = 9312 # log file, searchd run info is logged here # optional, default is 'searchd.log' log = C:\devel\sphinx-0.9.9-win32\data\log\searchd.log # query log file, all search queries are logged here # optional, default is empty (do not log queries) query_log = C:\devel\sphinx-0.9.9-win32\data\log\query.log # client read timeout, seconds # optional, default is 5 read_timeout = 5 # request timeout, seconds # optional, default is 5 minutes client_timeout = 300 # maximum amount of children to fork (concurrent searches to run) # optional, default is 0 (unlimited) max_children = 30 # PID file, searchd process ID file name # mandatory pid_file = C:\devel\sphinx-0.9.9-win32\data\log\searchd.pid # max amount of matches the daemon ever keeps in RAM, per-index # WARNING, THERE'S ALSO PER-QUERY LIMIT, SEE SetLimits() API CALL # default is 1000 (just like Google) max_matches = 1000 # seamless rotate, prevents rotate stalls if precaching huge datasets # optional, default is 1 seamless_rotate = 1 # whether to forcibly preopen all indexes on startup # optional, default is 0 (do not preopen) preopen_indexes = 0 } # --eof-- Once the configuration is done, its time to index our sql data, the command to use is 'indexer' as shown below. C:\devel\sphinx-0.9.9-win32\bin>indexer.exe --all --config C:\devel\sphinx-0.9.9-win32\addressbook.conf CONSOLE: Sphinx 0.9.9-release (r2117) Copyright (c) 2001-2009, Andrew Aksyonoff using config file 'C:\devel\sphinx-0.9.9-win32\addressbook.conf'... indexing index 'addressBookIndex'... collected 80 docs, 0.0 MB sorted 0.0 Mhits, 100.0% done total 80 docs, 5514 bytes total 0.057 sec, 96386 bytes/sec, 1398.43 docs/sec total 2 reads, 0.000 sec, 3.5 kb/call avg, 0.0 msec/call avg total 7 writes, 0.000 sec, 2.5 kb/call avg, 0.0 msec/call avg Note: As I told earlier that Sphinx creates 1 document for each row, as we had 80 rows in the database so a total of 80 docs are created. Time taken is also very very small, believe me I tried with half million rows and it took around 3-4 seconds :) cool isn't it? Once the index is up let's try to search few records, the utility command to perform search is 'search'. Ok Sphinx maharaj* please search for employee whose alias is u4732 C:\devel\sphinx-0.9.9-win32\bin>search.exe --config C:\devel\sphinx-0.9.9-win32\addressbook.conf u4732 CONSOLE: Sphinx 0.9.9-release (r2117) Copyright (c) 2001-2009, Andrew Aksyonoff using config file 'C:\devel\sphinx-0.9.9-win32\addressbook.conf'... index 'addressBookIndex': query 'u4732 ': returned 1 matches of 1 total in 0.001 sec displaying matches: 1. document=67, weight=1, doj=Fri Mar 20 00:00:00 2009 Id=67 FirstName=himanshu LastName=verma OfficeId=2 Title=Mrs Alias=u4732 [email protected] DOJ=2009-03-20 PhoneNo=+911234599108 words: 1. 'u4732': 1 documents, 1 hits words: 1. 'u4732': 1 documents, 1 hits As you can see above this is a unique record for Himanshu. Note: You see a lot of information for the result, this is because of following line in our configuration file sql_query_info = SELECT * FROM AddressBook WHERE id=$id If you want to see less columns you need to change the sql_query_info in configuration file. Let's try another search, sphinx maharaj* please tell me which all rows have gurleen or toshi in them. C:\devel\sphinx-0.9.9-win32\bin>search.exe --config C:\devel\sphinx-0.9.9-win32\addressbook.conf --any toshi gurleen CONSOLE: displaying matches: 1. document=63, weight=2, doj=Fri Sep 17 00:00:00 2010 Id=63 FirstName=toshi LastName=prakash OfficeId=1 Title=Mr Alias=u3766 [email protected] DOJ=2010-09-17 PhoneNo=+911234599104 2. document=72, weight=2, doj=Sun Jul 01 00:00:00 2007 Id=72 FirstName=gurleen LastName=bakshi OfficeId=5 Title=Miss Alias=u1423 [email protected] DOJ=2007-07-01 PhoneNo=+91532110003 Exactly two records were returned and this is what we were expecting. The following special operators and modifiers can be used when using the extended matching mode: operator OR: nikhil | sahil operator NOT: hello -sandy hello !sandy field search operator: @Email [email protected] For a complete set of search features , I advise you to go through http://sphinxsearch.com/docs/manual-0.9.9.html#searching link. Sphinx as Windows Service Now our main aim is to use sphinx with JAVA API, so let's move towards that now, before java can utilize the true power of Sphinx, we need to start 'searchd' as a windows service so that our java programme can connect to sphinx search engine. Let's install Sphinx as a windows service so that our java program can use this daemon service to query the index that we just created, the command is : C:\devel\sphinx-0.9.9-win32\bin>searchd.exe --install --config C:\devel\sphinx-0.9.9-win32\addressbook.conf --servicename --port 9312 SphinxSearch CONSOLE: Sphinx 0.9.9-release (r2117) Copyright (c) 2001-2009, Andrew Aksyonoff Installing service... Service 'SphinxSearch' installed succesfully. Well now the sphinx is ready to serve us on port 9312 Note: If you try to install Sphinx without admin rights, you may get following error messages. C:\devel\sphinx-0.9.9-win32\bin>searchd.exe --install --config C:\devel\sphinx-0.9.9-win32\addressbook.conf --servicename --port 9312 SphinxSearch CONSOLE: Installing service... FATAL: OpenSCManager() failed: code=5, error=Access is denied. Once done you can start the service as: c:\>sc start SphinxSearch (or alternatively from the services screen, start 'services.msc' in windows Run) If some how you want to delete the service , use c:\>sc delete SphinxSearch Let's create an adapter to fetch data from the database. package it.gogs.sphinx.util; import it.gogs.sphinx.AddressBoook; import it.gogs.sphinx.exception.AddressBookBizException; import it.gogs.sphinx.exception.AddressBookTechnicalException; import java.sql.CallableStatement; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; import org.apache.log4j.Logger; /** * Adapter to fetch data from the database. * * @author Munish Gogna * */ public class AddressBookAdapter { private static Logger logger = Logger.getLogger(AddressBookAdapter.class); private AddressBookAdapter() { // use in static way.. } private static Connection getConnection() throws AddressBookTechnicalException { String userName = "root"; String password = "root"; String url = "jdbc:mysql://localhost/addressbook"; try { Class.forName("com.mysql.jdbc.Driver").newInstance(); return DriverManager.getConnection(url, userName, password); } catch (Exception e) { throw new AddressBookTechnicalException("could not get connection"); } } public static List getAddressBookList(List addressIds) throws AddressBookTechnicalException, AddressBookBizException { List addressBoookList = new ArrayList(); if (addressIds == null || addressIds.size() == 0){ logger.error("AddressIds was null or empty, returning empty list"); return addressBoookList; } Connection connection = null; CallableStatement callableStatement = null; try { connection = getConnection(); callableStatement = connection.prepareCall("{ call search_address_book(?)}"); callableStatement.setString(1, Utils.toCommaString(addressIds)); callableStatement.execute(); ResultSet resultSet = callableStatement.getResultSet(); prepareResults(resultSet, addressBoookList); connection.close(); } catch (SQLException e) { logger.error("Problem connecting MYSQL - " + e.getMessage()); throw new AddressBookTechnicalException(e.getMessage()); } catch (AddressBookTechnicalException e) { logger.error("Problem connecting MYSQL - " + e.getMessage()); throw e; } finally{ if(connection != null){ try { connection.close(); } catch (SQLException e) { logger.error("Problem closing conection - " + e.getMessage()); e.printStackTrace(); } } } return addressBoookList; } private static void prepareResults(ResultSet resultSet, List addressBoookList) throws SQLException { AddressBoook addressBoook; while (resultSet.next()) { addressBoook = new AddressBoook(); addressBoook.setAlias(resultSet.getString("Alias")); addressBoook.setEmail(resultSet.getString("Email")); addressBoook.setfName(resultSet.getString("FName")); addressBoook.setlName(resultSet.getString("LName")); addressBoook.setOfficeLocation(resultSet.getString("Location")); addressBoook.setPhoneNo(resultSet.getString("PhoneNo")); addressBoook.setTitle(resultSet.getString("Title")); addressBoook.setDateOfJoining(resultSet.getDate("DOJ")); addressBoook.setId(resultSet.getLong("Id")); addressBoookList.add(addressBoook); } } } Next we create the SphinxInstance that will parse the keywords and date range and provide us a list of Ids that matches the search. package it.gogs.sphinx.util; import it.gogs.sphinx.DateRange; import it.gogs.sphinx.SearchCriteria; import it.gogs.sphinx.api.SphinxClient; import it.gogs.sphinx.api.SphinxException; import it.gogs.sphinx.api.SphinxMatch; import it.gogs.sphinx.api.SphinxResult; import it.gogs.sphinx.exception.AddressBookBizException; import java.util.ArrayList; import java.util.Date; import java.util.List; import org.apache.log4j.Logger; /** * Instance that will parse our free text and provide the results. * * Note: Make sure that 'searchd' is up and running before you use this class * @author Munish Gogna * */ public class SphinxInstance { private static String SPHINX_HOST = "localhost"; private static String SPHINX_INDEX = "addressBookIndex"; private static int SPHINX_PORT = 9312; private static SphinxClient sphinxClient; private static Logger logger = Logger.getLogger(SphinxInstance.class); static { sphinxClient = new SphinxClient(SPHINX_HOST, SPHINX_PORT); } public static List getAddressBookIds(SearchCriteria criteria) throws AddressBookBizException, SphinxException { List addressIdsList = new ArrayList(); try { if (Utils.isNull(criteria)) { logger.error("criteria is null"); throw new AddressBookBizException("criteria is null"); } if (Utils.isNull(criteria.getKeywords())) { logger.error("keyword is a required field"); throw new AddressBookBizException("keyword is a required field"); } DateRange dateRange = criteria.getDateRage(); if (!Utils.isNull(dateRange)) { if (Utils.isDateRangeValid(dateRange)) { // this is to filter results based on joining dates if they are provided sphinxClient.SetFilterRange("DOJ", getTimeInSeconds(dateRange.getFromDate()), getTimeInSeconds(dateRange.getToDate()), false); } else { logger.error(" fromDate/toDate should not be empty and 'fromDate' should be less than equal to 'toDate'"); throw new AddressBookBizException("fromDate/toDate should not be empty and 'fromDate' should be less than equal to 'toDate'"); } } sphinxClient.SetMatchMode(SphinxClient.SPH_MATCH_EXTENDED2); sphinxClient.SetSortMode(SphinxClient.SPH_SORT_RELEVANCE, ""); SphinxResult result = sphinxClient.Query(buildSearchQuery(criteria), SPHINX_INDEX, "buidling query for address book search"); SphinxMatch[] matches = result.matches; for (SphinxMatch match : matches) { addressIdsList.add(String.valueOf(match.docId)); } } catch (SphinxException e) { throw e; } catch (AddressBookBizException e) { throw e; } logger.info("Total record(s):" + addressIdsList.size()); return addressIdsList; } private static long getTimeInSeconds(Date time) { return time.getTime()/1000; } private static String buildSearchQuery(SearchCriteria criteria) throws AddressBookBizException { String keywords[] = criteria.getKeywords().split(" "); StringBuilder searchFor = new StringBuilder(); for (String key : keywords) { if (!Utils.isEmpty(key)) { searchFor.append(key); if (searchFor.length() > 1) { searchFor.append("*|*"); } } } searchFor.delete(searchFor.lastIndexOf("|*"), searchFor.length()); StringBuilder queryBuilder = new StringBuilder(); String query = searchFor.toString(); queryBuilder.append("@FName *" + query + " | "); queryBuilder.append("@LName *" + query + " | "); queryBuilder.append("@Title *" + query + " | "); queryBuilder.append("@Location *"+ query + " | "); queryBuilder.append("@Alias *" + query + " | "); queryBuilder.append("@Email *" + query + " | "); queryBuilder.append("@PhoneNo *" + query); logger.info("Sphinx Query: " + queryBuilder.toString()); return queryBuilder.toString(); } } Here is the interface that I will expose to the outside world (in my future article I will expose this interface as Web Service) import it.gogs.sphinx.AddressBoook; import it.gogs.sphinx.SearchCriteria; import it.gogs.sphinx.api.SphinxException; import it.gogs.sphinx.exception.AddressBookBizException; import it.gogs.sphinx.exception.AddressBookTechnicalException; import java.util.List; /** * * @author Munish Gogna * */ public interface AddressBook { /** * Returns the list of AddressBook objects based on search criteria. * * @param criteria * @throws AddressBookTechnicalException * @throws AddressBookBizException * @throws SphinxException */ public List getAddressBookList(SearchCriteria criteria) throws AddressBookTechnicalException, AddressBookBizException, SphinxException; } and here is the implementation class for the same. package it.gogs.sphinx.addressbook.impl; import java.util.List; import it.gogs.sphinx.AddressBoook; import it.gogs.sphinx.SearchCriteria; import it.gogs.sphinx.addressbook.AddressBook; import it.gogs.sphinx.api.SphinxException; import it.gogs.sphinx.exception.AddressBookBizException; import it.gogs.sphinx.exception.AddressBookTechnicalException; import it.gogs.sphinx.util.AddressBookAdapter; import it.gogs.sphinx.util.SphinxInstance; /** * Implementation for our Address Book example * * @author Munish Gogna * */ public class AddressBookImpl implements AddressBook{ public List getAddressBookList(SearchCriteria criteria) throws AddressBookTechnicalException, AddressBookBizException, SphinxException { List addressIds= SphinxInstance.getAddressBookIds(criteria); return AddressBookAdapter.getAddressBookList(addressIds); } } ok so far so good, let's run some tests now ............ package it.gogs.sphinx.test; import java.util.Calendar; import java.util.GregorianCalendar; import java.util.List; import it.gogs.sphinx.AddressBoook; import it.gogs.sphinx.DateRange; import it.gogs.sphinx.SearchCriteria; import it.gogs.sphinx.addressbook.AddressBook; import it.gogs.sphinx.addressbook.impl.AddressBookImpl; import it.gogs.sphinx.api.SphinxException; import it.gogs.sphinx.exception.AddressBookBizException; import it.gogs.sphinx.exception.AddressBookTechnicalException; import junit.framework.TestCase; /** * * @author Munish Gogna * */ public class AddressBookTest extends TestCase { private AddressBook addressBook; @Override protected void setUp() throws Exception { super.setUp(); addressBook = new AddressBookImpl(); } @Override protected void tearDown() throws Exception { super.tearDown(); } /** this should be a unique record for Himanshu */ public void test_search_for_himanshu() throws Exception { SearchCriteria criteria = new SearchCriteria(); // remember the first 'search' example?? criteria.setKeywords("u4732"); List addressList = addressBook.getAddressBookList(criteria); assertTrue(addressList.size() == 1); assertTrue("expecting himanshu here", "himanshu".equals(addressList.get(0).getfName())); } /** only two employees have name gurleen or toshi */ public void test_search_for_gurleen_or_toshi() throws Exception { SearchCriteria criteria = new SearchCriteria(); // remember the second 'search' example?? criteria.setKeywords("gurleen toshi"); List addressList = addressBook.getAddressBookList(criteria); assertTrue(addressList.size() == 2); assertTrue("expecting toshi here", "toshi".equals(addressList.get(0).getfName())); assertTrue("expecting gurleen here", "gurleen".equals(addressList.get(1).getfName())); } /** there are 16 people from jammu location */ public void test_search_for_people_from_jammu_location() throws Exception { SearchCriteria criteria = new SearchCriteria(); criteria.setKeywords("jammu"); List addressList = addressBook.getAddressBookList(criteria); assertTrue(addressList.size() == 16); } /** only Aalap, Manda and nitika are having title as Mrs and joined in 2010 */ public void test_joined_in_2010_with_title_Mrs() throws Exception { DateRange dateRange = new DateRange(); GregorianCalendar calendar1 = new GregorianCalendar(); calendar1.set(Calendar.YEAR, 2010); calendar1.set(Calendar.MONTH, Calendar.JANUARY); calendar1.set(Calendar.DAY_OF_MONTH, 1); dateRange.setFromDate(calendar1.getTime()); GregorianCalendar calendar2 = new GregorianCalendar(); calendar2.set(Calendar.YEAR, 2010); calendar2.set(Calendar.MONTH, Calendar.DECEMBER); calendar2.set(Calendar.DAY_OF_MONTH, 31); dateRange.setToDate(calendar2.getTime()); SearchCriteria criteria = new SearchCriteria(); criteria.setKeywords("Mrs"); criteria.setDateRage(dateRange); List addressList = addressBook.getAddressBookList(criteria); assertTrue("expecting 3 records here", addressList.size() == 3); } /** should get a business exception here */ public void test_without_specifying_keywords(){ SearchCriteria criteria = new SearchCriteria(); //criteria.setKeywords("Mrs"); try { addressBook.getAddressBookList(criteria); } catch (Exception e) { assertTrue(e instanceof AddressBookBizException); assertTrue(e.getMessage().indexOf("keyword is a required field") >-1); } } } How we update the Index once database changes? For these kinds of requirements, we can set up two sources and two indexes, with one "main" index for the data which only changes rarely (if ever), and one "delta" for the new documents. First Time data will go in the "main" index and the newly inserted address book entries will go into "delta". Delta index could then be reindexed very frequently, and the documents can be made available to search in a matter of minutes. Also one thing to take from this article is once 'searchd' daemon is running we can't index the data in normal way,we have to use --rotate option in such cases. For some applications where there is a timely batch update for the data, we can configure some cron job to reindex our documents in Sphinx as shown below. C:\devel\sphinx-0.9.9-win32\bin>indexer.exe --all --config C:\devel\sphinx-0.9.9-win32\addressbook.conf --rotate Capsule We asked Sphinx to provide us the Document Ids corresponding to our search parameters and then we used those Ids to fire database query. In case the data we want to return is included in Index (DOJ attribute for example in our case) we can skip the database portion, so choose wisely how much information (attributes) you want to include while you index your sql data. Well that's all ... it's time to say good bye. Take good care of your health and don't forget to vote, its a must :) - Munish Gogna
December 7, 2010
by Munish Gogna
· 38,178 Views · 2 Likes
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Practical PHP Testing Patterns: Assertion Message
In the previous article of this series, we saw how assertions are the key to self-validating tests. Even if an assertion's result is only a pass/fail value, programmers and testers find very handy to associate to the fail value some kind of additional information about the failure, to allow easier debugging without insertion of var_dump() and similar statements into the code. As I showed you in the previous article's code sample, assertions are useful the most when they fail, and in case they do, they should explain what happened so that a correction can be made quickly. An assertion that passes does not do anything; an assertion that fails shows an error. Whata happens when tests are failing The typical scenario is that of a large test suite, with hundreds or thousands of tests. At the time of a commit to the source code repository (or of a push if we're talking about git), the whole test suite must be green. Even if only one tests is red, the test suite is regarded as red. Sometimes, a regression is introduced by a programming error or an unforeseen scenario, and the output of the test suite becomes something like this: [12:30:02][giorgio@Desmond:~/txt/articles]$ phpunit assertionmessage.php PHPUnit 3.5.5 by Sebastian Bergmann. FFFF Time: 0 seconds, Memory: 3.75Mb There were 4 failures: 1) AssertionMessagesTest::testAsserTrue The object is not an Iterator. Failed asserting that is true. /home/giorgio/Dropbox/txt/articles/assertionmessage.php:9 2) AssertionMessagesTest::testAssertEquals The square root of 17 is not 4 but 4.1231056256177. Failed asserting that matches expected . /home/giorgio/Dropbox/txt/articles/assertionmessage.php:17 3) AssertionMessagesTest::testAssertContainsFailsWithCustomMessage The array does not contain 4. Failed asserting that an array contains . /home/giorgio/Dropbox/txt/articles/assertionmessage.php:24 4) AssertionMessagesTest::testAssertContains Failed asserting that an array contains . /home/giorgio/Dropbox/txt/articles/assertionmessage.php:36 FAILURES! Tests: 4, Assertions: 4, Failures: 4. The green tests are not noisy (which would be a smell), since they are not interesting at the moment. The red tests, which our focus is on, are shown with all the associated information. Along with the test name, the line of interest, and the kind of problem (failure/error), the assertion message is shown. How to write a meaningful message An assertion message can be passed as an argument of the assertion method, to be used in case of failure. Writing good assertion messages is an art, but before diving into some code to show you some messages I wrote, we can see how assertion messages are categorized in literature: Assertion-Identifying Message: includes information on which of the assertions in the same method caused the failure. This information can be for example the name of the checked variables. It's good to understand at a glance which assertion failed, but PHPUnit shows you the line of the test method that caused the failure, so it's not strictly necessary to include this kind of messages. Expectation-Describing Message: tells us what should have happened, but did not according to the data passed to the assertion method. Argument-Describing Message: when using assertions which are not very smart, like assertFalse() or assertTrue(), a failure would tell us by default only something like False was passed to assertTrue(). Adding an Argument-Describing Message will tell us instead The predicate on the set containing all red cars was false instead of true. Watch the test fail I can never say it enoug: when you write your tests, watch them fail (this mean also that each test should be written in advance with regard to the code it exercises, following the discipline of Test-Driven Development). This practice is not only useful for avoiding false positives, which are rare anyway, but to show at least for once the assertion message. You can check that when the test fails, the error message is meaningful and the test does not cause a Fatal Error. Watch your test fail to ensure that when they'll fail due to a regression in the future, you will be pleased by how fast you'll learn what's wrong. Example The code sample shows how to use PHPUnit's assertion methods with the $message optional argument. Any time you use basic methods like assertTrue(), a message is mandatory. The need for $message is inversely proportional to the specificity of the assertion: for example when assertContains() fails, PHPUnit has already valuable information in the the method itself to produce a readable error message. Note that the usage of "" (double quotes) enables fast composition of error messages via variable substitution. assertTrue($object instanceof Iterator, 'The object is not an Iterator.'); } public function testAssertEquals() { $expected = 4; $square = 17; $result = sqrt($square); $this->assertEquals($expected, $result, "The square root of $square is not $expected but $result."); } public function testAssertContainsFailsWithCustomMessage() { $array = array(1, 2, 3); $testElement = 4; $this->assertContains($testElement, $array, "The array does not contain $testElement."); } /** * This Assertion Message would be enough. It will even be better in some cases, * since PHPUnit would display nicely $testElement even if it was not "castable" * to a string (an object or array). */ public function testAssertContains() { $array = array(1, 2, 3); $testElement = 4; $this->assertContains($testElement, $array); } }
December 6, 2010
by Giorgio Sironi
· 6,974 Views
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Microchip's Embedded Software Development on the NetBeans Platform
Vince Sheard (pictured right) is the Manager of the MPLAB® Integrated Development Environment (IDE) team at Microchip Technology Inc. He has been working at Microchip for more than 10 years, and was the lead architect for the MPLAB X IDE version 1.0, prior to stepping into the management roll. This, the port of MPLAB to the NetBeans Platform, is the sixth major architecture change of the MPLAB IDE since its inception in 1992. Microchip Technology Inc., headquartered in Chandler, Arizona, was spun off from General Instrument in 1989. The Company went public in 1993, and is a leading provider of microcontroller, analog, and Flash-IP solutions, providing low-risk product development, lower total system cost and faster time to market for thousands of diverse customer applications worldwide. Headquartered in Chandler, Arizona, Microchip offers outstanding technical support along with dependable delivery and quality. For more information, visit the Microchip website at http://www.microchip.com. (The MPLAB X landing page is http://www.microchip.com/mplabx, which will be available in the next few days.) Hi, Vince. What's MPLAB, in a nutshell? MPLAB® is an integrated development environment or IDE. It is similar to other IDEs, but there are two important differences. The first difference is that the MPLAB IDE is our customers’ window into Microchip’s PIC® microcontrollers embedded in their designs. Many people believe they understand their PC, because it is “right here.” An embedded device is more difficult to get a handle on. It’s the brain of a product “over there.” It’s not a computer, it’s a thing. The MPLAB IDE gives embedded developers an opportunity to dig into the brain of that thing. The second important difference is that the MPLAB IDE seamlessly covers Microchip’s entire portfolio of more than 700 8-bit, 16-bit and 32-bit PIC microcontrollers. The differences between these devices are massive, from a tiny 6-pin, 8-bit microcontroller that could fit under your fingernail, to a huge 32-bit microcontroller that is much more powerful than the iconic IBM mainframe of last century. The MPLAB IDE provides a consistent and supportive environment in which to debug our customers’ original, creative works of software that differentiate their products. What are the MPLAB IDE’s main features and how does it distinguish itself from its competitors? Integrated development environments share many features: project creation and management, programmers’ editor, language tool integration and build tools, image preparation and programming, and debug facilities. These are the MPLAB X IDE’s main features, too. A large difference comes in the presentation of an embedded target, rather than a PC target, which presents a developer with a less coupled and less easily controlled object for their development. That tightens the focus, but there are other IDEs that support embedded development. The MPLAB X IDE is distinguished by its seamless and timely support of Microchip devices, the vast ecosystem of tightly integrated compilers and hardware tools that also support those devices, and the evolutionary grace of a tool that has grown with our customers and technologies until the three form a smooth and supportive system for developing innovative embedded products. What are the typical technical challenges of an application of this kind? The principal challenge we face is how to provide the facilities developers need in the most intuitive and useful way possible. It’s easy to provide tons and tons of features, but with the GUI technologies of today, one can only present a small fraction of what is provided and available for use. One of the gauges for how well we’ve done our job is when our customers present a fine point of usage that we’ve already discussed and disagreed on how to implement. Those "complaints" are really wonderful because they come from expert tool users who understand the tools they are using. Of course, we are always hustling to present new Microchip devices in the same light that we present established devices. We’re also challenged to exploit the advanced debug facilities of new devices in a way that is most beneficial for our customers. What's the architecture of the application and why did you make the choices that you did? We’re moving away from a Windows OS-only, COM-based architecture. As our customers’ development sophistication has grown, so have their needs. Our customers now require Linux, Mac, and Windows support. Microchip is a worldwide company with customers who may only be fluent in a single language, so that impacts our choices. We also have a number of educational institutions who place interesting demands on the IDE, along with a number of advanced customers who are very forward-looking and are really pushing the envelope of what was previously thought possible. The most telling choice we had to make, though, was the choice of NetBeans as a fully capable, modern, lightweight and flexible platform for our next-generation MPLAB X IDE: Where does the NetBeans Platform fit into all of this? NetBeans is unique among current open-source IDE platform offerings, in that it is the most advanced for addressing our primary challenge, which I described above. The NetBeans IDE presents standard operations in a way that really minimizes hunting around and wasting time, to find out how to accomplish what you need to do. Take, for instance, the classic edit, compile, debug “cycle.” In NetBeans, like in other IDEs, the edit part is pretty easy: open the source file in the programmers’ editor and make the changes you need. It’s really not much different than editing a document with a word processor. The next step is where the difference really shows. In some IDEs, you have to compile or build an image and then figure out how to load it and start a debugging session. In some IDEs, that’s just brutal to figure out, especially in embedded systems where, as we said, the target is not “right here,” it’s “over there.” In NetBeans, it’s a single button press (DebugRun), even in an embedded context like ours. After that, the rest of the steps are taken care of. If any errors occur during the sequence, we take it home by capturing the errors and placing the user in context for an easy solution; and the ability to move on. That’s just one example. NetBeans is way ahead of the curve compared to other menu/toolbar/property sheet IDEs. What are the 3 main benefits of the NetBeans Platform, in this context? First and foremost is the ability to really optimize developers’ time. That’s a major factor in our customers’ focus. Second is the fact that NetBeans is a modern, lightweight and fully capable IDE platform. It doesn’t suffer from the bloat and outdated aspects of some other IDE platforms. Included with these benefits are the abilities to localize the IDE and to utilize it on multiple operating systems. Last, but not least, is the huge benefit of a professionally executed development, maintained by a focused organizing committee and maintained by a tight-knit development community—all headed by the Oracle contributions. That’s a significant departure from some other high-profile, open-source platforms that are available. How did you end up choosing the NetBeans Platform over its alternatives? When you consider all of the benefits I just mentioned, I think it’s pretty much a no-brainer. How did you get started with it? We first discussed the concepts with Sun Microsystems, as we wanted to provide a benefit to the overall NetBeans IDE from an embedded side. We created a proof of concept by plugging in our existing debuggers to the NetBeans IDE on a Windows operating system. We were fortunate to find someone who previously worked within Sun Microsystems on the NetBeans Platform, who came in on contract and gave us some one-on-one training. This was mainly because we had an aggressive schedule and wanted to be able to get up to speed faster. Any tips and tricks for others going down the same road? The mail lists are very helpful. We found many things we wanted to do being asked by others on the mailing lists. Many of the developers monitor these lists frequently, and respond more often than not in a timely fashion. The documentation suite, videos, written documents and interaction with the community are all extremely helpful in getting to the root of any matter quickly. The IDE is well organized and uses common techniques within the code base, which quickly become familiar. Other platforms treat information as job security. Some people may know, but they want you to pay for the information, in one way or another. Not so with NetBeans; everyone involved is completely open and collaborative. Any specific things that surprised you about the NetBeans Platform (in a good or bad way)? NetBeans prevents development with any form of interdependency between modules. For instance, you cannot have A->B and B->A. This really is a good thing and ensures that you break your modules up more to create a common module. The way JUnit is integrated into the IDE makes it so seamless to create your unit tests while developing the code. Source-code revision control worked quite smoothly from within the IDE. A hindrance for us is that there is no way to view a block of memory in hex form, when running under Java (using the JVM debugger). This is something often required when doing embedded development. Since we are developing code for our debug tools, we wanted to see the code blocks being transported from the IDE to the tool in hex, but could not. Anything else you'd like to share? It is great how fully featured the editor is. We are often so deep in developing what is required for the embedded side that we still discover things the editor does that we hadn’t come across. We are using the NetBeans IDE to create our own IDE, which is a completely new, yet compatible, incarnation of our IDE. The NetBeans developers at Oracle/Sun are extremely open to assist in getting value added to the current IDE, which makes our job even easier.
December 3, 2010
by Geertjan Wielenga
· 20,992 Views · 10 Likes
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A Closer Look at JUnit Categories
JUnit 4.8 introduced Categories: a mechanism to label and group tests, giving developers the option to include or exclude groups (or categories.) This post presents a brief overview of JUnit categories and some unexpected behavior I have found while using them. 1. Quick Introduction The following example shows how to use categories: (adapted from JUnit’s release notes) public interface FastTests { /* category marker */ } public interface SlowTests { /* category marker */ } public class A { @Category(SlowTests.class) @Test public void a() {} } @Category(FastTests.class}) public class B { @Test public void b() {} } @RunWith(Categories.class) @IncludeCategory(SlowTests.class) @ExcludeCategory(FastTests.class) @SuiteClasses({ A.class, B.class }) public class SlowTestSuite {} Lines 1, 2: we define two categories, FastTests and SlowTests. JUnit categories can be defined as classes or interfaces. Since a category acts like a label or marker, my intuition tells me to use interfaces. Line 5: we use the annotation @org.junit.experimental.categories.Category to label test classes and test methods with one or more categories. Lines 6, 9: test methods and test classes can be marked as belonging to one or more categories of tests. Labeling a test class with a category automatically includes all its test methods in such category. Lines 14 to 18: currently programmatic test suites (line 17) are the only way to specify which test categories (line 14) should be included (line 15) or excluded (line 16) when the suite is executed. I find this approach (especially the way test classes need to included in the suite) too verbose and not so flexible. Hopefully Ant, Maven and IDEs will provide support for categories (with a simpler configuration) in the very near future. Note: I recently discovered ClasspathSuite, a project that simplifies the creation of programmatic JUnit test suites. For example, we can specify we want to include in a test suite all tests whose names end with “UnitTest.” 2. Category Subtyping Categories also support subtyping. Let’s say we have the category IntegrationTests that extends SlowTests: public interface IntegrationTests extends SlowTests {} Any test class or test method labeled with the category IntegrationTests is also part of the category SlowTests. To be honest, I don’t know how handy category subtyping could be. I’ll need to experiment with it more to have an opinion. 3. Categories and Test Inheritance 3a. Method-level Categories JUnit behaves as expected when test inheritance is combined with method-level categories. For example: public class D { @Category(GuiTest.class) @Test public void d() {} } public class E extends D { @Category(GuiTest.class) @Test public void e() {} } @RunWith(Categories.class) @IncludeCategory(GuiTest.class) @SuiteClasses(E.class) public class TestSuite {} As I expected, when running TestSuite, test methods d and e are executed (both methods belong to the GuiTest category and E inherits method d from superclass D.) Nice! 3b. Class-level Categories On the other hand, unless I’m missing something, I think I found some strange behavior in JUnit in this scenario. Consider the following classes: @Category(GuiTest.class) public class A { @Test public void a() {} } public class B extends A { @Test public void b() {} } @RunWith(Categories.class) @IncludeCategory(GuiTest.class) @SuiteClasses(B.class) public class TestSuite {} As we can see, TestSuite should execute the tests in B that belong to the category GuiTest. I was expecting TestSuite to execute test method a, even though B is not marked as a GuiTest. Here is my reasoning: test method a belongs to the category GuiTest because test class A is labeled with such category test class B is an A and it inherits test method a Therefore, TestSuite should execute test method a. But it doesn’t! Here is a screenshot of the results I get (click to see full size.) There are two ways to fix this issue, depending on what test methods we want to actually run: Label class B with GuiTest. In this case, both methods, a and b, will be executed. Label method a with GuiTest. In this case, only method a will be executed. (I’ll be posting a question regarding this issue in the JUnit mailing list shortly.) 4. Categories vs. TestNG Groups (You saw this one coming, didn’t you?) Categories (or groups) have been part of TestNG for long time. Unlike JUnit’s, TestNG’s groups are defined as simple strings, not as classes or interfaces. As a static typing lover, I was pretty happy with JUnit categories. By using an IDE, we could safely rename a category or look for usages of a category within a project. Even though my observation was correct, I was missing one important point: all this works great as long as your test suite is written in Java. In the real world, I’d like to define a test suite in either Ant or Maven (or Gradle, or Rake.) In this scenario, having categories as Java types does not bring any benefit. In fact, I suspect it would be very verbose and error-prone to specify the fully-qualified name of a category in a build script. Renaming a category now would be limited to a text-based “search and replace.” Ant and Maven really need to provide a way to specify JUnit categories, clever enough to be fool-proof. As you may expect, I prefer the simplicity and pragmatism of TestNG’s groups. Update: my good friend (and creator of the TestNG framework,) Cédric, reminded me that we can use regular expressions to include or exclude groups in a test suite (details here.) This is really powerful! 5. My Usage of Categories I’m not using JUnit categories in my test suites yet. I started to look into JUnit categories because I wasn’t completely happy with the way we recognized GUI tests in FEST. We recognize test methods or test classes as “GUI tests” if they have been annotated with the @GUITest (provided by FEST.) When a “GUI test” fails, FEST automatically takes a screenshot of the desktop and includes it in the JUnit or TestNG HTML report. The problem is, our @GUITest annotation is duplicating the functionality of JUnit categories. To solve this issue, I created a JUnit extension that recognizes test methods or test classes as “GUI tests” if they belong to the GuiTest category. At this moment GuiTest is an interface provided by FEST, but I’m thinking about letting users specify their own GuiTest category as well. I also refactored this functionality out of the Swing testing module, expecting to reuse it once I implement a JavaFX testing module :) You can find the FEST code that deals with JUnit categories at github. 6. Conclusion Having the ability to label and group tests via categories is really a great feature. I still have some reservations about the practicality of defining categories as Java types, the lack of support for this feature from Ant and Maven (not JUnit’s fault,) and the unexpected behavior I noticed when combining class-level categories and test inheritance. On the brighter side, categories are still an experimental, non-final feature. I’m sure will see many improvements in future JUnit releases :) Feedback is always welcome. From http://alexruiz.developerblogs.com/?p=1711
December 2, 2010
by Alex Ruiz
· 35,959 Views
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Creating and Deploying JAX-WS Web Service on Tomcat 6
Some years back I had to provide a wrapper around an EJB 3.0 remote service to come up with a simple web service project that would be deployed over Tomcat and accessed in a simple http way due to some accessibility issues. Now as I cannot reveal the actual requirement I implemented that time so here I am presenting a simple demo kind of service with following signature. public AccountDetails getAccountDetails(String accountNo, SecurityToken token); The service will return the account details of a particular account number, provided the token is valid (generated using some Security module of the application). In nutshell, the client will ask for a token from Security module and then invoke this method. The service will validate the token to see if the caller can invoke the method or not? In general you should use handlers (message interceptors that can be easily plugged in to the JAX-WS runtime to do additional processing of the inbound and outbound messages) to validate the stuff, freeing implementation class from that overhead, it is just an example exercise so our implementation class will check the security token also.Sounds good.. lets move ahead. Libraries we are going to use include JAXB and JAX-WS, as both of them have sensible defaults, the number of annotations can be kept to the minimum. Also in my opinion, it is always best to develop WSDL and schemas by hand to ensure that the service contract is appropriately defined and also that the schema can be re-used (by other services) and extended if necessary. I do not prefer using annotations for automatically producing WSDL and schema at runtime so let's start with the definition, i am using inline schema as we have a very simple requirement here, though we should have schema definitions in separate xsd files. accounts.wsdl: I am not going to explain the In and outs of this wsdl , in a nutshell it defines one operation 'getAccountDetails' which takes accountNo and returns back the account details like account type, balance etc. Please note that I have also added a security header token that will validate the caller (left to the implementation of the service). Now as we are done with our wsdl and schema, let's generate the portable artifacts from our service definition. JAX-WS includes a tool that can do this for us, we will use this tool to generate portable artifacts like Service Endpoint Interface (SEI), Service and Exception classes.These artifacts can be packaged in a WAR file with the WSDL and schema documents along with the endpoint implementation to be deployed. To generate the artifacts , we run following command: wsimport C:\devel\workspace\webservice\WebContent\WEB-INF\wsdl\accounts.wsdl -p com.mg.ws -keep -Xnocompile This will create the following artifacts in com.mg.ws package. AccountDetails.java AccountDetailsFault.java AccountDetailsFault_Exception.java AccountDetailsPortType.java AccountDetailsTO.java GeAccountDetailsINTO.java ObjectFactory.java package-info.java SecurityToken.java Now as we have got all the artifacts we are ready to implement our service, the interface we need to implement is AccountDetailsPortType , so let's do it. Here is our dummy implementation class: package com.mg.ws.impl;import java.math.BigDecimal;import javax.jws.WebService;import com.mg.ws.AccountDetailsFault;import com.mg.ws.AccountDetailsFault_Exception;import com.mg.ws.AccountDetailsPortType;import com.mg.ws.AccountDetailsTO;import com.mg.ws.GeAccountDetailsINTO;import com.mg.ws.SecurityToken;@WebService(name = "AccountDetailsService", portName = "AccountDetailsPort", endpointInterface = "com.mg.ws.AccountDetailsPortType", wsdlLocation = "WEB-INF/wsdl/accounts.wsdl", targetNamespace="http://gognamunish.com/accounts") public class AccountDetailsServiceImpl implements AccountDetailsPortType {public AccountDetailsTO getAccountDetails(GeAccountDetailsINTO parameters, SecurityToken requestHeader) throws AccountDetailsFault_Exception { AccountDetailsTO detailsTO = new AccountDetailsTO(); // validate token validateToken(requestHeader); // populate response detailsTO = getDetailsFromSomewhere (parameters.getAccountNo()); return detailsTO; } private AccountDetailsTO getDetailsFromSomewhere(String accountNo) throws AccountDetailsFault_Exception { if(accountNo == null || accountNo.trim().length()==0){ AccountDetailsFault faultInfo = new AccountDetailsFault(); faultInfo.setFaultInfo("missing account number"); faultInfo.setMessage("account number is required field"); throw new AccountDetailsFault_Exception("account no missing", faultInfo); } AccountDetailsTO detailsTO = new AccountDetailsTO(); detailsTO.setAccNo(accountNo); detailsTO.setAccType("SAVING"); detailsTO.setBalance(new BigDecimal(10000)); return detailsTO; } private void validateToken(SecurityToken requestHeader) throws AccountDetailsFault_Exception { if ("83711070".equals(requestHeader.getToken()) && requestHeader.getValidTill() != null){ System.out.println("token processed successfully..."); } else { AccountDetailsFault faultInfo = new AccountDetailsFault(); faultInfo.setFaultInfo("Header token Invalid"); faultInfo.setMessage("can't help"); throw new AccountDetailsFault_Exception("invalid token", faultInfo); } } This is just a dummy implementation for illustration purpose only. Now as our service implementation is done, we proceed to package this in a war and deploy it on tomcat. Now we create a standard web.xml, which defines WSServletContextListener, WSServlet and structure of a web project. com.sun.xml.ws.transport.http.servlet.WSServletContextListener AccountDetailsServicecom.sun.xml.ws.transport.http.servlet.WSServlet 1AccountDetailsService/details Next we create a sun-jaxws.xml, defines the web service implementation class. This file is required regardless of whether we publish our web service on tomcat, glassfish or any other server. OK so far so good , let's build our application and deploy it on tomcat, here is the ant script. NOTE: jars in lib should be carefully chosen, otherwise it will make your life hell. Now let's test the application, point your browser to http://localhost:8080/account/details , if you see something like this, it means you have successfully deployed the service. Now let's test the service, we can use the client generated by the wsimport tool as : public static void main(String[] args) throws Exception { AccountDetails accountDetails = new AccountDetails(); AccountDetailsPortType port = accountDetails.getAccountDetailsPort(); AccountDetailsTO details = port.getAccountDetails(new GeAccountDetailsINTO(), new SecurityToken()); } For those who want to invoke the service using soap stuff, they can use tool like soapUI (can be downloaded from www.soapui.org), lets make some soap calls now: case: invalid security header case: valid security header By default, Tomcat does not comes with any JAX-WS dependencies, So, you have to include it manually. Go here Download JAX-WS RI distribution, you will find the wsimport tool in lib directory. Please note for running this project you can just skip this step as I have already done this step for you and included the required libraries in the lib folder of the project. I have included eclipse project for this demo, please get it from resource section. To deploy just change build.properties to point to TOMCAT_HOME and run ant build. Thats all for now ... Please provide your valuable comments or any suggestion and DON'T forget to vote :) It's Munish Gogna signing off now :)
December 1, 2010
by Munish Gogna
· 69,148 Views · 1 Like
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