many times i end up using source files from somebody else. and such files might have a lot of empty lines in it i want to get removed. the question is: how to get rid of empty or blank lines in the eclipse editor view? or even better: how to merge multiple empty lines into one? shortcut: ctrl+d deleting a line is easy: i place the cursor on a line and press ctrl+d (for line d elete). that works as well for multiple line selection. using the ‘ mother of all shortcuts ‘ reveals even more shortcut options: delete commands this approach is fine, but manual. there must be something better. search-and-replace: regular expression and there is: to automatically remove empty lines, the search-and-replace functionality helps. for this i press ctrl-f (for find) and configure it like this: regular expression to remove empty lines the magic is using a regular expression checkbox. it uses the regular expression ^\s*\n to find one or multiple empty lines and replaces it with ‘nothing’. that way i can clean up a full file and get rid of all empty lines. if i do not remember the syntax of regular expressions any more, then there is help too: the dialog has content assist available: content assist so that way pressing ctrl+space helps a lot: content assist help merging empty lines with this in mind, it is easy to do something more advanced : to merge multiple empty lines into a single one. again, a regular expression does the magic work: merging multiple empty lines into a single one with this, the regular expression ^\s*\n finds one or multiple empty lines (as before), and it replaces it with a single empty line: \r now the sources need much less screen real estate . happy removing:-)

these days i’m playing with backbone and using public api as a source. the web browser has one horrible feature: it don’t allow you to fetch any external resource to our host due to the cross-origin restriction. for example if we have a server at localhost we cannot perform one ajax request to another host different than localhost. nowadays there is a header to allow it: access-control-allow-origin . the problem is that the remote server must set up this header. for example i was playing with github’s api and github doesn’t have this header. if the server is my server, is pretty straightforward to put this header but obviously i’m not the sysadmin of github, so i cannot do it. what the solution? one possible solution is, for example, create a proxy server at localhost with php. with php we can use any remote api with curl (i wrote about it here and here for example). it’s not difficult, but i asked myself: can we create a dummy proxy server with php to handle any request to localhost and redirects to the real server, instead of create one proxy for each request?. let’s start. problably there is one open source solution (tell me if you know it) but i’m on holidays and i want to code a little bit (i now, it looks insane but that’s me ). the idea is: ... $proxy->register('github', 'https://api.github.com'); ... and when i type: http://localhost/github/users/gonzalo123 and create a proxy to : https://api.github.com/users/gonzalo123 the request method is also important. if we create a post request to localhost we want a post request to github too. this time we’re not going to reinvent the wheel, so we will use symfony componets so we will use composer to start our project: we create a conposer.json file with the dependencies: { "require": { "symfony/class-loader":"dev-master", "symfony/http-foundation":"dev-master" } } now php composer.phar install and we can start coding. the script will look like this: register('github', 'https://api.github.com'); $proxy->run(); foreach($proxy->getheaders() as $header) { header($header); } echo $proxy->getcontent(); as we can see we can register as many servers as we want. in this example we only register github. the application only has two classes: restproxy , who extracts the information from the request object and calls to the real server through curlwrapper . request = $request; $this->curl = $curl; } public function register($name, $url) { $this->map[$name] = $url; } public function run() { foreach ($this->map as $name => $mapurl) { return $this->dispatch($name, $mapurl); } } private function dispatch($name, $mapurl) { $url = $this->request->getpathinfo(); if (strpos($url, $name) == 1) { $url = $mapurl . str_replace("/{$name}", null, $url); $querystring = $this->request->getquerystring(); switch ($this->request->getmethod()) { case 'get': $this->content = $this->curl->doget($url, $querystring); break; case 'post': $this->content = $this->curl->dopost($url, $querystring); break; case 'delete': $this->content = $this->curl->dodelete($url, $querystring); break; case 'put': $this->content = $this->curl->doput($url, $querystring); break; } $this->headers = $this->curl->getheaders(); } } public function getheaders() { return $this->headers; } public function getcontent() { return $this->content; } } the restproxy receive two instances in the constructor via dependency injection (curlwrapper and request). this architecture helps a lot in the tests , because we can mock both instances. very helpfully when building restproxy. the restproxy is registerd within packaist so we can install it using composer installer: first install componser curl -s https://getcomposer.org/installer | php and create a new project: php composer.phar create-project gonzalo123/rest-proxy proxy if we are using php5.4 (if not, what are you waiting for?) we can run the build-in server cd proxy php -s localhost:8888 -t www/ now we only need to open a web browser and type: http://localhost:8888/github/users/gonzalo123 the library is very minimal (it’s enough for my experiment) and it does’t allow authorization. of course full code is available in github .

First, read this. Why passwords have never been weaker—and crackers have never been stronger. There are numerous important lessons in this article. One of the small lessons is that changing your password every sixty or ninety days is farcical. The rainbow table algorithms can crack a badly-done password in minutes. Every 60 days, the cracker has to spend a few minutes breaking your new password. Why bother changing it? It only annoys the haxorz; they'll be using your account within a few minutes. However. That practice is now so ingrained that it's difficult to dislodge from the heads of security consultants. The big lesson, however, is profound. Work Experience Recently, I got a request from a developer on how to encrypt a password. We have a Python back-end and the developer was asking which crypto package to download and how to install it. "Crypto?" I asked. "Why do we need crypto?" "To encrypt passwords," they replied. I spat coffee on my monitor. I felt like hitting Caps Lock in the chat window so I could respond like this: "NEVER ENCRYPT A PASSWORD, YOU DOLT." I didn't, but I felt like it. Much Confusion The conversation took hours. Chat can be slow that way. Also, I can be slow because I need to understand what's going on before I reply. I'm a slow thinker. But the developer also needed to try stuff and provide concrete code examples, which takes time. At the time, I knew that passwords must be hashed with salt. I hadn't read the Ars Technica article cited above, so I didn't know why computationally intensive hash algorithms are best for this. We had to discuss hash algorithms. We had to discuss algorithms for generating unique salt. We had to discuss random number generators and how to use an entropy source for a seed. We had to discuss http://www.ietf.org/rfc/rfc2617.txt in some depth, since the algorithms in section 3.2.2. show some best practices in creating hash summaries of usernames, passwords, and realms. All of this was, of course, side topics before we got to the heart of the matter. What's Been Going On After several hours, my "why" questions started revealing things. The specific user story, for example, was slow to surface. Why? Partly because I didn't demand it early enough. But also, many technology folks will conceive of a "solution" and pursue that technical concept no matter how difficult or bizarre. In some cases, the concept doesn't really solve the problem. I call this the "Rat Holes of Lost Time" phenomena: we chase some concept through numerous little rat-holes before we realize there's a lot of activity but no tangible progress. There's a perceptual narrowing that occurs when we focus on the technology. Often, we're not actually solving the problem. IT people leap past the problem into the solution as naturally as they breathe. It's a hard habit to break. It turned out that they were creating some additional RESTful web services. They knew that the RESTful requests needed proper authentication. But, they were vague on the details of how to secure the new RESTful services. So they were chasing down their concept: encrypt a password and provide this encrypted password with each request. They were half right, here. A secure "token" is required. But an encrypted password is a terrible token. Use The Framework, Luke What's most disturbing about this is the developer's blind spot. For some reason, the existence of other web services didn't enter into this developer's head. Why didn't they read the code for the services created on earlier sprints? We're using Django. We already have a RESTful web services framework with a complete (and high quality) security implementation. Nothing more is required. Use the RESTful authentication already part of Django. In most cases, HTTPS is used to encrypt at the socket layer. This means that Basic Authentication is all that's required. This is a huge simplification, since all the RESTful frameworks already offer this. The Django Rest Framework has a nice authentication module. When using Piston, it's easy to work with their Authentication handler. It's possible to make RESTful requests with Digest Authentication, if SSL is not being used. For example, Akoha handles this. It's easy to extend a framework to add Digest in addition to Basic authentication. For other customers, I created an authentication handler between Piston and ForgeRock OpenAM so that OpenAM tokens were used with each RESTful request. (This requires some care to create a solution that is testable.) Bottom Lines Don't encrypt passwords. Ever. Don't write your own hash and salt algorithm. Use a framework that offers this to you. Read the Ars Technica article before doing anything password-related.

Today I learned a neat trick to organize imports in Eclipse. Of course, one can use Ctrl + Shift + O to remove the unused imports at file level. But what if you want to remove the unused imports for several files, may be at package level? Simple – in the Package Explorer window, right click on the package that you want to modify and then select source -> Organize Imports which will analyse all the files inside that package and then remove the unused imports. One more nifty trick is that you can automatically organize the imports when you save the file. To enable this, go to Windows -> Preferences -> Java -> Editor -> Save Actions and then enable Perform the selected action on save -> Organize imports. After this, whenever you save a java file, eclipse will remove the unused imports automatically.

Learn about pros, cons, and basics of Spring security and data, plus Envers integration.

This is the second article of the series on Spring Integration. This article builds on top of the first article where we introduced Spring Integration. Context setting In the first article, we created a simple java application where A message was sent over a channel, It was intercepted by a service i.e. POJO and modified. It was then sent over a different channel The modified message was read from the channel and displayed. However, in doing this - keeping in mind that we were merely introducing the concepts there - we wrote some Spring specific code in our application i.e. the test classes. In this article we will take care of that and make our application code as insulated from Spring Integration api as possible. This is done by, what Spring Integration calls gateways. Gateways exist for the sole purpose of abstracting messaging related "plumbing" code away from "business" code. The business logic might really not care whether a functionality is being achieved be sending a message over a channel or by making a SOAP call. This abstraction - though logical and desirable - have not been very practical, till now. It is probably worth having a quick look at the Spring Integration Reference Manual at this point. However, if you are just getting started with Spring Integration, you are perhaps better off following this article for the moment. I would recommend you get your hands dirty before returning to reference manual, which is very good but also very exhaustive and hence could be overwhelming for a beginner. The gateway could be a POJO with annotations (which is convenient but in my mind beats the whole purpose) or with XML configurations (can very quickly turn into a nightmare in any decent sized application if unchecked). At the end of the day it is really your choice but I like to go the XML route. The configuration options for both styles are detailed out in this section of the reference implementation. Spring Integration with Gateways So, let's create another test with gateway throw in for our HelloWorld service (refer to the first article of this series for more context). Let's start with the Spring configuration for the test. File: src/test/resources/org/academy/integration/HelloWorld1Test-context.xml In this case, all that is different is that we have added a gateway. This is an interface called org.academy.integration.Greetings. It interacts with both "inputChannel" and "outputChannel", to send and read messages respectively. Let's write the interface. File: /src/main/java/org/academy/integration/Greetings.java package org.academy.integration; public interface Greetings { public void send(String message); public String receive(); } And then we add the implementation of this interface. Wait. There is no implementation. And we do not need any implementation. Spring uses something called GatewayProxyFactoryBean to inject some basic code to this gateway which allows it to read the simple string based message, without us needing to do anything at all. That's right. Nothing at all. Note - You will need to add more code for most of your production scenarios - assuming you are not using Spring Integration framework to just push around strings. So, don't get used to free lunches. But, while it is here, let's dig in. Now, lets write a new test class using the gateway (and not interact with the channels and messages at all). File: /src/test/java/org/academy/integration/HelloWorld1Test.java package org.academy.integration; import static org.junit.Assert.*; import org.junit.Test; import org.junit.runner.RunWith; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.test.context.ContextConfiguration; import org.springframework.test.context.junit4.SpringJUnit4ClassRunner; @RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration public class HelloWorld1Test { private final static Logger logger = LoggerFactory .getLogger(HelloWorld1Test.class); @Autowired Greetings greetings; @Test public void test() { greetings.send("World"); assertEquals(greetings.receive(), "Hello World"); logger.debug("Spring Integration with gateways."); } } Our test class is much cleaner now. It does not know about channels, or messages or anything related to Spring Integration at all. It only knows about a greetings instance - to which it gave some data by .send() method - and got modified data back by .receive() method. Hence, the business logic is oblivious of the plumbing logic, making for a much cleaner code. Now, simply type "mvn -e clean install" (or use m2e plugin) and you should be able to run the unit test and confirm that given string "World" the HelloWorld service indeed returns "Hello World" over the entire arrangement of channels and messages. Again, something optional but I highly recommend, is to run "mvn -e clean install site". This - assuming you have correctly configured some code coverage tool (cobertura in my case) will give you a nice HTML report showing the code coverage. In this case it would be 100%. I have blogged a series on code quality which deals this subject in more detail, but to cut long story short, it is very important for me to ensure that whatever coding practice / framework I use and recommend use, complies to some basic code quality standards. Being able to unit test and measure that is one such fundamental check that I do. Needless to say, Spring in general (including Spring integration) passes that check with flying colours. Conclusion That's it for this article. Happy coding.

I (https://github.com/kelemen) have been (and I still do) use Maven for development of Java code. My main reason for using Maven for development is its great NetBeans IDE support, so that I don't need to maintain IDE project files separately. As much as I like this support in the Maven world, I feel the limits of Maven every day I use it. Since I first saw the Gradle project, I knew that this is the least that I've always wanted from a build tool. So I started to look for NetBeans IDE support for Gradle. To my sadness there is only support for Eclipse and Idea. Aside from the fact that I prefer to use NetBeans IDE, I felt the IDE support to be limited for Gradle, (although the last time I read about Gradle support in IDEA, it seemed promising). Not long ago, I came across Geertjan's plugin and I felt that that writing such plugin is possible without enormous effort. So I downloaded his sources and started to analyze them and rewrite the plugin, so that it works with most Gradle scripts. There are many new features available in my version, such as these: slow tasks are done in a background thread source paths are retrieved from the model "test single" Screenshots: Project menus: Project dependencies: Project debug test: However, I removed subprojects and now each project needs to be opened manually, it is more efficient if you don't plan to edit all the subprojects; the drawback is that you cannot open projects without a build.gradle. The main problem with Gradle daemon performance is that on the first project load, Gradle downloads every single dependency. After that, I found the performance acceptable (especially after I implemented caching of already loaded projects). I have tested it with a relatively large project (>60 subprojects, lots of Java code): It took me about 2 minutes to load the project which seems ok to me for such an enormous project. Other than the project loading, the performance depends on NetBeans which is good. How to try it There is currently no compiled version of the plugin, so you have to compile it for yourself, if you want to try it. You can clone/download the sources from here: https://github.com/kelemen/netbeans-gradle-project After downloading the sources, open the project in NetBeans IDE. There generally two approaches you could consider: Generate the .nbm file (by choosing "Create NBM" in the project's popup) and install the plugin as you would do with any other third-party plugin. "Run" the project. This is the safest thing to do because this will start a new NetBeans instance with a brand new user directory (in the build folder). This way your own NetBeans installation will be unaffected. Help I would appreciate I'm pretty new to the NetBeans APIs (i.e., this is my first time using them), so someone might help me with the project dependencies (possibly Mavenize the plugin). And if it is possible, allow for the plugin to rely on a user specified installation of Gradle (there is some risk in it because Gradle does not seem to be very backward compatible). If you happen to know the Project API in NetBeans well, that could prove really helpful, so that I don't need to spend days figuring out, how things need to be done in the API. How to contact me You can contact me through my GitHub account: https://github.com/kelemen

ever wondering what could be a keyboard shortcut for something in eclipse? in my post on 10 best eclipse shortcuts the question came up how to traverse through all the open files in the editor. finding a shortcut is easy if you know the the mother of all eclipse shortcuts . i press ctrl+3 and enter a search term like ‘switch’, and it shows me all shortcuts with ‘switch’ in the description: ctrl plus 3 shows all shortcuts so with this i know that ctrl+tab is to switch to the next editor. let’s try it out: ctrl+tab popup window a small pop-up window shows all open sources of the editor view: pressing ctrl+tab repeatedly will iterate through the source files. that way i can quickly switch to another source file without leaving my fingers from the keyboard. happy switching

In my office laptop, I have installed two versions of JDK. For the office work, I need JDK6 because the internal framework needs it. I’m using JDK7 for my personal projects and exploring the latest and greatest in Java. I have two versions of Eclipse too (one for office work and one is the latest Juno). But, the tricky thing is to manage these multiple JDKs and IDEs. It’s a piece of cake if I just use Eclipse for compiling my code, because the IDE allows me to configure multiple versions of Java runtime. Unfortunately (or fortunately), I have to use the command line/shell to build my code. So, it is important that I have the right version of JDK present in the PATH and other related environment variables (such as JAVA_HOME). Manually modifying the environment variables every time I want to switch between JDKs, isn’t a happy task. But, thanks to Windows Powershell, I’m able to write a scriplet that can do the heavy-lifting for me. Basically, what I want to achieve is to set PATH variable to add Java bin folder and set the JAVA_HOME environment variable and then launch the correct Eclipse IDE. And, I want to do this with a single command. Let’s do it. Open a Windows Powershell. I prefer writing custom Windows scripts in my profile file so that it is available to run when ever I open the shell. To edit the profile, run this command: notepad.exe $profile - the $profile is a special variable that points to your profile file. Write the below script in the profile file and save it. function myIDE{ $env:Path += "C:\vraa\java\jdk7\bin;" $env:JAVA_HOME = "C:\vraa\java\jdk7" C:\vraa\ide\eclipse\eclipse set-location C:\vraa\workspace\myproject play } function officeIDE{ $env:Path += "C:\vraa\java\jdk6\bin;" $env:JAVA_HOME = "C:\vraa\java\jdk6" C:\office\eclipse\eclipse } Close and restart the Powershell. Now you can issue the command myIDE which will set the proper PATH and environment variables and then launch the eclipse IDE. As you can see, there are two functions with different configurations. Just call the function name that you want to launch from the Powershell command line (myIDE or officeIDE).

the great thing with blogging is: i receive great comments, questions and ideas. the great thing with eclipse/codewarrior is that the extensions are almost unlimited . for my earlier post on hiding the toolbar i received a tip for another way which even is better: a plugin to switch eclipse into full screen mode. here is how to install it and how it looks… the plugin is available from http://code.google.com/p/eclipse-fullscreen/ . download the zip file. the zip file has the cn.pande.eclipsex.fullscreen_.jar file. copy that file inside the codewarrrior or eclipse eclipse\plugins folder. after launching eclipse there is new entry in the window menu: full screen menu item this switches eclipse into full screen mode: eclipse in full screen mode this hides the toolbar, menu and status bar, and i have more space available for what matters how to get out of full screen mode: press esc key to exit full screen mode. ctrl+alt+z is the default shortcut to toggle between ‘normal’ and ‘full screen’ mode. happy full screening

screen real estate is important to me. especially working on a small notebook screen i want to get the most out of it. and i know: all the cool (and fancy) ui items in eclipse have a price. so how to get more space for important things like my source files? eclipse has feature to hide the toolbar completely. for this i simply use the context menu and select ‘hide toolbar’: hide toolbar while this is great, there is one little problem: how to get it back? obviously there is no toolbar any more where i could use a context menu like ‘show toolbar’ . the solution: there is a menu item for this under window > show toolbar: show toolbar menu happy toolbaring

Here are the most important subjects for software engineering, with brief explanations: 1.Object oriented analysis & design: For better maintainability, reusability and faster development, the most well accepted approach, shortly OOAD and its SOLID principals are very important for software engineering. 2.Software quality factors: Software engineering depends on some very important quality factors. Understanding and applying them is crucial. 3.Data structures & algorithms: Basic data structures like array, list, stack, tree, map, set etc. and useful algorithms are vital for software development. Their logical structure should be known. 4. Big-O notation: Big-O notation indicates the performance of an algorithm/code section. Understanding it is very important for comparing performances. 5.UML notation: UML is the universal and complete language for software design & analysis. If there is lack of UML in a development process, it feels there is no engineering. 6.Software processes and metrics: Software enginnering is not a random process. It requires a high level of systematic and some numbers to monitor those techniques. So, processes and metrics are essential. 7.Design patterns: Design patterns are standard and most effective solutions for specific problems. If you don't want to reinvent the wheel, you should learn them. 8.Operating systems basics: Learning OS basics is very important because all applications runs on it. By learning it, we can have better vision, viewpoints and performance for our applications. 9.Computer organization basics: All applications including OS requires a hardware for physical interaction. So, learning computer organization basics is vital again for better vision, viewpoints and performance. 10.Network basics: Network is related with computer organization, OS and the whole information transfer process. In any case we will face it while software development. So, it is important to learn network basics. 11.Requirement analysis: Requirement analysis is the starting point and one of the most important parts of software engineering. Performing it correctly and practically needs experience but it is very essential. 12.Software testing: Testing is another important part of software engineering. Unit testing, its best practices and techniques like black box, white box, mocking, TDD, integration testing etc. are subjects which must be known. 13.Dependency management: Library (JAR, DLL etc.) management, and widely known tools (Maven, Ant, Ivy etc.) are essential for large projects. Otherwise, antipatterns like Jar Hell are inevitable. 14.Continuous integration: Continuous integration brings easiness and automaticity for testing large modules, components and also performs auto-versioning. Its aim and tools (like Hudson etc.) should be known. 15.ORM (Object relational mapping): ORM and its widely known implementation Hibernate framework is an important technique for mapping objects into database tables. It reduces code length and maintenance time. 16.DI (Dependency Injection): DI or IoC (Inversion of Control) and its widely known implementation Spring framework makes life easy for object creation and lifetime management on big enterprise applications. 17.Version controlling systems: VCS tools (SVN, TFS, CVS etc.) are very important by saving so much time for collaborative works and versioning. Their logical viewpoint and standard cammands should be known. 18.Internationalization (i18n): i18n by extracting strings into external files is the best way of supporting multiple languages in our applications. Its practices on different IDEs and technologies must be known. 19.Architectural patterns: Understanding architectural design patterns (like MVC, MVP, MVVM etc.) is essential for producing a maintainable, clean, extendable and testable source code. 20.Writing clean code: Working code is not enough, it must be readable and maintainable also. So, code formatting and readable code development techniques are needed to be known and applied.

in this article we'll show you how you can use the w3c geolocation api to measure the speed and the heading of your car while driving. this article further uses svg to render the speed gauge and heading compass. what we'll create in this article is the following: here you can see two gauges. one will show the heading you're driving to, and the other shows the speed in kilometers. you can test this out yourself by using the following link: open this in gps enable device . once opened the browser will probably ask you to allow access to your location. if you enable this and start moving, you'll see the two gauges move appropriately. getting all this to work is actually very easy and consists of the following steps: alter the svg images so we can rotate the needle and add to page. use the geolocation api to determine the current speed and heading update the needle based on the current and previous value we'll start with the svg part. alter the svg images so we can rotate the needle and add to page for the images i decided to use svg. svg has the advantage that it can scale without losing detail, and you can easily manipulate and animate the various parts of a svg image. both the svg images were copied from openclipart.org : compass rose speedometer these are vector graphics, both created using illustrator. before we can rotate the needles in these images we need to make a couple of small changes to the svg code. with svg you can apply matrix transformations to each svg element, with this you can easily rotate, skew, scale or translate a component. besides the matrix transformation you can also apply the rotation and translation directly using the translate and rotate keywords. in this example i've used the translaten and rotate functions directly. when working with these functions you have to take into account that the rotate function doesn't rotate around the center of the component, it rotates around point 0,0. so we need to make sure that for our needles the point we want to rotate around is set at 0,0. without diving into too much details, i removed the two needles from the image, and added them as a seperate group to the svg image. i then made sure the needles we're drawn relative to the 0,0 point i wanted to rotate around. for the speedometer the needle is now defined as this: and for the compass the needle is defined like this: if you know how to read svg, you can see that these figures are now drawn around their rotation point (the bottom center for the speedomoter and the center for the compass). as you can see we also added a specific id for both these elements. this way we can reference them directly from our javascript later on and update the transform property from a jquery animation. next we just need to add these to the page. for this i used d3.js , which has all kinds of helper functions for svg and which you can use to load these elements like this: function loadgraphics() { d3.xml("assets/compass.svg", "image/svg+xml", function(xml) { document.body.appendchild(xml.documentelement); }); d3.xml("assets/speed.svg", "image/svg+xml", function(xml) { document.body.appendchild(xml.documentelement); }); } and with this we've got our visualization components ready. use the geolocation api to determine the current speed and heading the next step is using the geolocation api to access the speed and heading properties. you can get this information from the position object that is provided to you by this api: interface position { readonly attribute coordinates coords; readonly attribute domtimestamp timestamp; }; this object has a coordinate object that contains the information we're looking for: interface coordinates { readonly attribute double latitude; readonly attribute double longitude; readonly attribute double? altitude; readonly attribute double accuracy; readonly attribute double? altitudeaccuracy; readonly attribute double? heading; readonly attribute double? speed; }; a lot of useful attributes, but we're only interested in these last two. the heading (from 0 to 360) shows the direction we're moving in, and the speed in meters per second is, as you've probably guessed, the speed we're moving at. there are two different options to get these values. we can poll ourselves for these values (e.g. setinterval) or we can wait wacth our position. in this second case you automatically recieve an update. in this example we use the second approach: function initgeo() { navigator.geolocation.watchposition( geosuccess, geofailure, { enablehighaccuracy:true, maximumage:30000, timeout:20000 } ); //movespeed(30); //movecompassneedle(56); } var count = 0; function geosuccess(event) { $("#debugoutput").text("geosuccess: " + count++ + " : " + event.coords.heading + ":" + event.coords.speed); var heading = event.coords.heading; var speed = event.coords.speed; if (heading != null && speed !=null && speed > 0) { movecompassneedle(heading); } if (speed != null) { // update the speed movespeed(speed); } } with this piece of code, we register a callback function on the watchposition. we also add a couple of properties to the watchposition function. with these properties we tell the api to use gps (enablehighaccuracy) and set some timeout and caching values. whenever we receive an update from the api the geosuccess function is called. this function recieves a position object (shown earlier) that we use to access the speed and the heading. based on the value of the heading and the speed we update the compass and the speedomoter. update the needle based on the current and previous value to update the needles we use jquery animations for the easing. normally you use a jquery animation to animatie css properties of an object, but you can also use this to animate arbitrary properties. to animate the speedomoter we use the following: var currentspeed = {property: 0}; function movespeed(speed) { // we use a svg transform to move to correct orientation and location var translatevalue = "translate(171,157)"; // to is in the range of 45 to 315, which is 0 to 260 km var to = {property: math.round((speed*3.6/250) *270) + 45}; // stop the current animation and run to the new one $(currentspeed).stop().animate(to, { duration: 2000, step: function() { $("#speed").attr("transform", translatevalue + " rotate(" + this.property + ")") } }); } we create a custom object, currentspeed, with a single property. this property is set to the rotate ratio that reflects the current speed. next, this property is used in a jquery animation. note that we stop any existing animations, should we get an update when the current animation is still running. in the step property of the animation we set the transfrom value of the svg element. this will rotate the needle, in two seconds, from the old value to the new value. and to animate the compass we do pretty much the same thing: var currentcompassposition = {property: 0}; function movecompassneedle(heading) { // we use a svg transform to move to correct orientation and location var translatevalue = "translate(225,231)"; var to = {property: heading}; // stop the current animation and run to the new one $(currentcompassposition).stop().animate(to, { duration: 2000, step: function() { $("#compass").attr("transform", translatevalue + " rotate(" + this.property + ")") } }); } there is a smal bug i ran into with this setup. sometimes my phone lost its gps signal (running firefox mobile), and that stopped the dials moving. refreshing the webpage was enough to get things started again however. i might change this to actively pull the information using the getcurrentlocation api call, to see whether that works better. another issue is that there is no way, at least that i found, for you to disable the phone entering sleep mode from the browser. so unless you configure your phone to not go to sleep, the screen will go black.

I've seen a lot of discussion about how to monitor Camel based applications. Most people are looking for the following features: ability to view services (contexts, endpoints, routes), to view performance statistics (route throughput, etc) and to perform basic operations (start/stop routes, send messages, etc). This post will breakdown the options (that I know of) that are available today (as of Camel 2.8). If you have used other approaches or know of other ongoing development in this area, please let me know. JMX APIs Camel uses JMX to provide a standardized way to access metadata about contexts/routes/endpoints defined in a given application. Also, you can use JMX to interact with these components (start/stop routes, etc) in some interesting ways. I recently had some very specific Camel/ActiveMQ monitoring requests from a client. After looking at the options, we ended up building a standalone Tomcat web app that used JSPs, jQuery, Ajax and JMX APIs to view route/endpoint statistics, manage Camel routes (stop, start, etc) and monitor/manipulate ActiveMQ queues. It provided some much needed visibility and management features for our Camel/ActiveMQ based message processing application... CamelContext If you have a handle to the CamelContext, there are various APIs that can help describe and manage routes and endpoints. These are used by the existing Camel Web Console and can be used to build custom interface to retrieve and use this information in various ways... here are some of the notable APIs... getRouteDefinitions() getEndpoints() getEndpointsMap() getRouteStatus(routeId) startRoute(routeId) stopRoute(routeId) removeRoute(routeId) addRoutes(routeBuilder) suspendRoute(routeId) resumeRoute(routeId) With a little creativity, you can use these APIs to manage/monitor and re-wire a Camel application dynamically. Camel Web Console This console provides web and REST interfaces to Camel contexts/routes/endpoints and allows you to view/manage endpoints/routes, send messages to endpoints, viewing route statistics, etc. That being said, using this web console with an existing Camel application is tricky at the moment. It's currently deployed as a war file that only has access to the CamelContext defined in its embedded spring XML file. Though the entire camel-web project can be embedded and customized in your application if you desire (and know Scalate). Given my recent client requirements, I opted to build my own basic app using JSPs/JMX as described above. There has been some recent support for deploying this console in OSGI, where it should be able to view any CamelContexts deployed in the container, etc. However, I'm yet to see this work...more on this later. Using Camel APIs There are also a number of Camel technologies/patterns that can be used to add monitoring to existing routes. wire tap - can add message logging (to a file or JMS queue/topic, etc) or other inline processing advicewith - can be used to modify existing routes to apply before/after operations or add/remove operations in a route intercept - can be used to intercept Exchanges while they are in route, can apply to all endpoints, certain endpoints or just starting endpoints BrowsableEndpoint - is an interface which Endpoints may implement to support the browsing of the exchanges which are pending or have been sent on it. That being said, it takes some creativity to use these effectively and caution to not adversely affect the routes you are trying to monitor. Hyperic HQ You can use this tool to monitor Servicemix (or any process), but it more geared towards system monitoring and JVM stats. I didn't find it useful for any Camel specific monitoring. jConsole/VisualVM these are standard JMX based consoles. They aren't web based and can't be customized (easily anyways) to provide anything more than a tree-like view of JMX MBeans. If you know where to look though, you can do a lot with it. Summary These are just some quick notes at this point. As I learn about other ways of monitoring Camel, I'll update this list and give some more detailed comparison. Any comments are welcome...

I decided to share some tips about this EE environment javaMail api configuration.

Manipulating JAXWS header on the client Side like adding WSS username token or logging saop message.

Introduction: Building modern HTTP/RESTful/RPC services has become very easy with the new ASP.NET Web API framework. Using ASP.NET Web API framework, you can create HTTP services which can be accessed from browsers, machines, mobile devices and other clients. Developing HTTP services is now quite easy for ASP.NET MVC developer becasue ASP.NET Web API is now included in ASP.NET MVC. In addition to developing HTTP services, it is also important to return meaningful response to client if a resource(uri) not found(HTTP 404) for a reason(for example, mistyped resource uri). It is also important to make this response centralized so you can configure all of 'HTTP 404 Not Found' resource at one place. In this article, I will show you how to handle 'HTTP 404 Not Found' at one place. Description: Let's say that you are developing a HTTP RESTful application using ASP.NET Web API framework. In this application you need to handle HTTP 404 errors in a centralized location. From ASP.NET Web API point of you, you need to handle these situations, No route matched. Route is matched but no {controller} has been found on route. No type with {controller} name has been found. No matching action method found in the selected controller due to no action method start with the request HTTP method verb or no action method with IActionHttpMethodProviderRoute implemented attribute found or no method with {action} name found or no method with the matching {action} name found. Now, let create a ErrorController with Handle404 action method. This action method will be used in all of the above cases for sending HTTP 404 response message to the client. public class ErrorController : ApiController { [HttpGet, HttpPost, HttpPut, HttpDelete, HttpHead, HttpOptions, AcceptVerbs("PATCH")] public HttpResponseMessage Handle404() { var responseMessage = new HttpResponseMessage(HttpStatusCode.NotFound); responseMessage.ReasonPhrase = "The requested resource is not found"; return responseMessage; } } You can easily change the above action method to send some other specific HTTP 404 error response. If a client of your HTTP service send a request to a resource(uri) and no route matched with this uri on server then you can route the request to the above Handle404 method using a custom route. Put this route at the very bottom of route configuration, routes.MapHttpRoute( name: "Error404", routeTemplate: "{*url}", defaults: new { controller = "Error", action = "Handle404" } ); Now you need handle the case when there is no {controller} in the matching route or when there is no type with {controller} name found. You can easily handle this case and route the request to the above Handle404 method using a custom IHttpControllerSelector. Here is the definition of a custom IHttpControllerSelector, public class HttpNotFoundAwareDefaultHttpControllerSelector : DefaultHttpControllerSelector { public HttpNotFoundAwareDefaultHttpControllerSelector(HttpConfiguration configuration) : base(configuration) { } public override HttpControllerDescriptor SelectController(HttpRequestMessage request) { HttpControllerDescriptor decriptor = null; try { decriptor = base.SelectController(request); } catch (HttpResponseException ex) { var code = ex.Response.StatusCode; if (code != HttpStatusCode.NotFound) throw; var routeValues = request.GetRouteData().Values; routeValues["controller"] = "Error"; routeValues["action"] = "Handle404"; decriptor = base.SelectController(request); } return decriptor; } } Next, it is also required to pass the request to the above Handle404 method if no matching action method found in the selected controller due to the reason discussed above. This situation can also be easily handled through a custom IHttpActionSelector. Here is the source of custom IHttpActionSelector, public class HttpNotFoundAwareControllerActionSelector : ApiControllerActionSelector { public HttpNotFoundAwareControllerActionSelector() { } public override HttpActionDescriptor SelectAction(HttpControllerContext controllerContext) { HttpActionDescriptor decriptor = null; try { decriptor = base.SelectAction(controllerContext); } catch (HttpResponseException ex) { var code = ex.Response.StatusCode; if (code != HttpStatusCode.NotFound && code != HttpStatusCode.MethodNotAllowed) throw; var routeData = controllerContext.RouteData; routeData.Values["action"] = "Handle404"; IHttpController httpController = new ErrorController(); controllerContext.Controller = httpController; controllerContext.ControllerDescriptor = new HttpControllerDescriptor(controllerContext.Configuration, "Error", httpController.GetType()); decriptor = base.SelectAction(controllerContext); } return decriptor; } } Finally, we need to register the custom IHttpControllerSelector and IHttpActionSelector. Open global.asax.cs file and add these lines, configuration.Services.Replace(typeof(IHttpControllerSelector), new HttpNotFoundAwareDefaultHttpControllerSelector(configuration)); configuration.Services.Replace(typeof(IHttpActionSelector), new HttpNotFoundAwareControllerActionSelector()); Summary: In addition to building an application for HTTP services, it is also important to send meaningful centralized information in response when something goes wrong, for example 'HTTP 404 Not Found' error. In this article, I showed you how to handle 'HTTP 404 Not Found' error in a centralized location. Hopefully you will enjoy this article too.

Microsoft offered programmers several different ways of dealing with the asynchronous programming since .NET 1.0. The first model was Asynchronous programming model or APM for short. The pattern is implemented with two methods named BeginOperation and EndOperation. .NET 4 introduced new pattern – Task Asynchronous Pattern and with the introduction of .NET 4.5, Microsoft added language support for language integrated asynchronous coding style. You can check the MSDN for more samples and information. I will assume that you are familiar with it and have written code using it. You can wrap existing APM pattern into TPL pattern using the Task.Factory.FromAsync methods. For example: public static Task> ExecuteAsync(this DataServiceQuery query, object state) { return Task.Factory.FromAsync>(query.BeginExecute, query.EndExecute, state); } It is easy to wrap most of the asynchronous functions this way, but some cannot be since the wrapper functions assume that the last two parameters to the BeginOperation are AsyncCallback and object, and there are some versions of asynchronous operations that have different specifications. Examples: 1. Extra parameters after the object state parameter: IAsyncResult DataServiceContext.BeginExecuteBatch( AsyncCallback callback, object state, params DataServiceRequest[] queries); 2. Missing the expected object state parameter and different return type: ICancelableAsyncResult BeginQuery(AsyncCallback callBack); WorkItemCollection EndQuery(ICancelableAsyncResult car); Short solution for the first example The short and elegant way for wrapping the first example is to provide the following wrapper: public static Task ExecuteBatchAsync(this DataServiceContext context, object state, params DataServiceRequest[] queries) { if (context == null) throw new ArgumentNullException("context"); return Task.Factory.FromAsync( context.BeginExecuteBatch(null, state, queries), context.EndExecuteBatch); } We simply call the Begin method ourselves and then wrap it using an another overload for FromAsync function. The longer way However, we can fully wrap it ourselves by simulating what the FromAsync wrapper does. The complete code is listed below. public static Task ExecuteBatchAsync(this DataServiceContext context, object state, params DataServiceRequest[] queries) { // this will be our sentry that will know when our async operation is completed var tcs = new TaskCompletionSource(); try { context.BeginExecuteBatch((iar) => { try { var result = context.EndExecuteBatch(iar as ICancelableAsyncResult); tcs.TrySetResult(result); } catch (OperationCanceledException ex) { // if the inner operation was canceled, this task is cancelled too tcs.TrySetCanceled(); } catch (Exception ex) { // general exception has been set bool flag = tcs.TrySetException(ex); if (flag && ex as ThreadAbortException != null) { tcs.Task.m_contingentProperties.m_exceptionsHolder.MarkAsHandled(false); } } }, state, queries); } catch { tcs.TrySetResult(default(DataServiceResponse)); // propagate exceptions to the outside throw; } return tcs.Task; } Besides educational benefits, writing the full wrapper code allows us to add cancellation, logging and diagnostic information. Once we understand how to wrap APM pattern, We can now tackle the second problem easily. Handling the BeginQuery/EndQuery We will first create our own wrapper function in the spirit of the above code with the notable difference that we use the ICancelableAsyncResult interface instead of the IAsyncResult. public static class TaskEx { public static Task FromAsync(Func beginMethod, Func endMethod) { if (beginMethod == null) throw new ArgumentNullException("beginMethod"); if (endMethod == null) throw new ArgumentNullException("endMethod"); var tcs = new TaskCompletionSource(); try { beginMethod((iar) => { try { var result = endMethod(iar as ICancelableAsyncResult); tcs.TrySetResult(result); } catch (OperationCanceledException ex) { tcs.TrySetCanceled(); } catch (Exception ex) { bool flag = tcs.TrySetException(ex); if (flag && ex as ThreadAbortException != null) { tcs.Task.m_contingentProperties.m_exceptionsHolder.MarkAsHandled(false); } } }); } catch { tcs.TrySetResult(default(TResult)); throw; } return tcs.Task; } } The code is pretty self-explanatory and we can go ahead with the wrapping. There are four different operations that are exposed both in synchronous and asynchronous version: Query, LinkQuery, CountOnlyQuery and RegularQuery. The extension methods are short since we have already created our generic wrapper above: public static Task RunQueryAsync(this Query query) { return TaskEx.FromAsync(query.BeginQuery, query.EndQuery); } public static Task RunLinkQueryAsync(this Query query) { return TaskEx.FromAsync(query.BeginLinkQuery, query.EndLinkQuery); } public static Task RunCountOnlyQueryAsync(this Query query) { return TaskEx.FromAsync(query.BeginCountOnlyQuery, query.EndCountOnlyQuery); } public static Task RunRegularQueryAsync(this Query query) { return TaskEx.FromAsync(query.BeginRegularQuery, query.EndRegularQuery); } That is it for today, you can write your own handy extensions easily for APM functions out there.

Performance problems are one of the biggest challenges to expect when designing and implementing Java EE related technologies.

Apache Camel has a very powerful bean injection framework which allows developers to focus only on solving business problems. However there are situations when you need to do a little bit more. Read below to see how easy it is to setup aspects (AspectJ) in Apache Camel. Use case In Qualitas I have an installation route which consists of 10 mandatory and 2 optional processors. Some processors like property resolvers or validators don't modify contents of message's body so I have to always copy body from the in message to out message. Also, all my processors require some headers to function properly. Finally, I would like to get a status updated after each of my processors either finishes processing successfully or fails. Setting up AspectJ This is just a plain Spring configuration frankly. All you have to do is: Apache Camel processor aspect To define aspect in AspectJ I used AspectJ-specific @Aspect and @Around annotations: @Aspect @Component @Order(Ordered.LOWEST) public class HeadersAndBodyCopierAspect { @Around("execution(* com.googlecode.qualitas.internal.installation..*.process(org.apache.camel.Exchange)) && args(exchange) && target(org.apache.camel.Processor)") public Object copyHeadersAndBody(ProceedingJoinPoint pjp, Exchange exchange) throws Throwable { Object retValue = pjp.proceed(); Message in = exchange.getIn(); Message out = exchange.getOut(); // always copy headers out.setHeaders(in.getHeaders()); // if output body is empty copy it from input if (out.getBody() == null) { out.setBody(in.getBody()); } return retValue; } } I also used @Order Spring-specific annotation to control the order of execution of my aspects and @Component for automatic context scanning. Now, the join point is defined as execution(* com.googlecode.qualitas.internal.installation..*.process(org.apache.camel.Exchange)) && args(exchange) && target(org.apache.camel.Processor) which basically means: apply this aspect to all process methods which are defined in all classes in com.googlecode.qualitas.internal.installation or subpackages and which take Exchange object as an argument there can be many custom methods whose names may be process and whose argument may be Exchange, so I added one more constraint, this class has to be an instance of Processor args(exchange) allows me to add Exchange object as an argument to my aspect More complex aspects and source code Of course in Spring you can inject other beans directly into your aspects. I used it in my ProcessStatusUpdaterAspect aspect which you can find in Qualitas repo on GoogleCode or GitHub. If you are interested in trying out the whole Qualitas system take a look at the following two links: BuildingTheProject and RunningTheProject. cheers, Łukasz