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The Latest Integration Topics

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Integration Testing FTP Connections in .NET
when writing testable code, your first port of call is often to abstract any dependencies and make them easy to mock. this is the same for any of your codebase that talks to ftp servers. testing the way your code behaves under real world conditions makes integration tests important regardless of abstraction, though. here’s a simple trick to test ftp code in the wild. a recent project of mine has involved writing code that talks to ftp servers with the goal of adding additional continuous integration automation to a project. although all of my main methods are easily abstracted and injectable, my project still needs to actually talk to ftp servers at the end of the day, and i need to test that these very methods do the right thing when they are met with different conditions; be they bad credentials, lack of read/write permissions etc. the challenge integration tests can be brittle at the best of times, so ensuring that they are repeatable and can be setup and torn down can often be almost as much of a challenge as writing your actual code itself. an ftp server is usually a static service that is installed on a server. you might think that running one and ensuring it stays up and doesn’t get hacked just so that all your integration tests work is a necessary evil, but there is an easier way. run local. run often. i was running an ftp server on my build server just so that it was “always around” for my tests until i stumbled across an interesting project over on github to do just this . the approach i'm about to show you doesn’t need you to go to the effort of running a dedicated server at all. all you need to do is add a single executable to your unit test project and wrap your unit test in a using statement. the ftp server executable is a single file ftp server called ftpdmin which offers a read/write ftp server that can be fired up from the command line with a minimum feature set and only a few command line parameters to make it all tick. by implementing idisposable the helper class that wraps around this command line exe allows you to take advantage of the using() pattern to take care of your executable’s lifetime and have it die when your code is done testing. steps to make it happen download ftpdmin from here . add the exe to the root of your test project (you can put this anywhere, but you’ll have to update the helper class below). now add the exe to your project (i.e “view all items” in your test project’s solution explorer, and add the exe). set the exe to “copy always” in it’s solution properties. add the following code to a helper class in your test project: public class ftptestserver: idisposable { private readonly process ftpprocess; public ftptestserver(string rootdirectory, int port = 21, bool allowuploads = true) { var psinfo = new processstartinfo { filename = appdomain.currentdomain.basedirectory + "\\ftpdmin.exe", arguments = string.format("-p {0} -ha 127.0.0.1 \"{1}\" {2}", port, rootdirectory, allowuploads ? string.empty : "-g"), windowstyle = processwindowstyle.hidden }; ftpprocess = process.start(psinfo); } public void dispose() { if (ftpprocess.hasexited) return; ftpprocess.kill(); ftpprocess.waitforexit(); } } now you can enjoy being able to write really clean integration testing code that starts and ftp server every time you run your tests and then tear it down when your test is done. an example integration test showing connecting to “127.0.0.1”: [testmethod] public void ftpcode_upload_canconnect() { try { // fire up a new ftp server instance using (new ftptestserver(rootdirectory: "./")) { // code that talks to an ftp server on 127.0.0.1 } } catch (webexception e) { assert.fail("failed to connect to our ftp server"); } } how awesome is that? the power of using ftpdmin is that it can be told to deny write permissions to simulate bad user permissions as well: [testmethod] public void ftpcode_upload_throwswebexception() { try { // fire up a new ftp server instance using (new ftptestserver(rootdirectory: "./", allowuploads: false)) { // code that talks to an ftp server on 127.0.0.1 } } catch (webexception e) { assert.fail("our code failed to upload a file because of invalid permissions"); } } all in all, the above has been a complete lifesaver when it comes to making my integration test projects portable – if a new developer joins my project, they instantly get access to my ftp test harness just by pulling down my project’s source code.
September 27, 2012
by Douglas Rathbone
· 6,649 Views
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Introducing the New Date and Time API for JDK 8
Date and time handling in Java is a somewhat tricky part when you are new to the language. Time can be accessed via the static method System.currentTimeMillis() which returns the current time in milliseconds from January 1st 1970. If you prefer to work with Objects instead you can use java.util.Date, a class whose methods are mostly deprecated in recent versions of Java. To work with time offsets, say add one month to a date, there is java.util.GregorianCalendar. All in all, those methods described here are not very convenient to work with. Java 7 and below are lacking a good date and time API. The Joda Time library is a common drop-in if you need to work with date/time. With JSR 310 (Java Specification Request) this is about to change. JSR 310 adds a new date, time and calendar API to Java 8. The ThreeTen project provides a reference implementation to this new API and can already be utilized in current Java projects (I however recommend not to do this for production). As the README states: The API is currently considered usable and accurate, yet incomplete and subject to change. If you use this API you must be able to handle incompatible changes in later versions. Building ThreeTen Building the ThreeTen project is relatively easy. It requires both Git and Ant to be installed on your system. git clone git://github.com/ThreeTen/threeten.git cd threeten ant This will first fetch the most recent version of ThreeTen and then start the build process using ant. Note that building the library also requires either OpenJDK 1.6 or Oracle JDK 1.6. JSR 310 The new API specifies a number of new classes which are divided into the categories of continuous and human time. Continuous time is based on Unix time and is represented as a single incrementing number. Class Description Instant A point in time in nanoseconds from January 1st 1970 Duration An amount of time measured in nanoseconds Human time is based on fields that we use in our daily lifes such as day, hour, minute and second. It is represented by a group of classes, some of which we will discuss in this article. Class Description LocalDate a date, without time of day, offset or zone LocalTime the time of day, without date, offset or zone LocalDateTime the date and time, without offset or zone OffsetDate a date with an offset such as +02:00, without time of day or zone OffsetTime the time of day with an offset such as +02:00, without date or zone OffsetDateTime the date and time with an offset such as +02:00, without a zone ZonedDateTime the date and time with a time zone and offset YearMonth a year and month MonthDay month and day Year/MonthOfDay/DayOfWeek/... classes for the important fields DateTimeFields stores a map of field-value pairs which may be invalid Calendrical access to the low-level API Period a descriptive amount of time, such as "2 months and 3 days" In addition to the above classes three support classes have been implemented. The Clock class wraps the current time and date, ZoneOffset is a time offset from UTC and ZoneId defines a time zone such as 'Australia/Brisbane'. Using the API Getting the current time The current time is represented by the Clock class. The class is abstract, so you can not create instances of it. The systemUTC() static method will return the current time based on your system clock and set to UTC. import javax.time.Clock; Clock clock = Clock.systemUTC(); To use the default time zone on your system there also is systemDefaultZone(). Clock clock = Clock.systemDefaultZone(); The millis() method can then be used to access the current time in milliseconds from January 1st, 1970. This shows, that the Clock class and all subclasses are wrapped around System.currentTimeMillis(). Clock clock = Clock.systemDefaultZone(); long time = clock.millis(); Working with time zones To work with time zones you need to import the ZoneId class. The class provides a method to get the default system time zone: import javax.time.ZoneId; import javax.time.Clock; ZoneId zone = ZoneId.systemDefault(); Clock clock = Clock.system(zone); As seen above, the ZoneId can then be used to get an instance of a Clock with that time zone. Other time zones can be accessed by their name, e.g.: ZoneId zone = ZoneId.of("Europe/Berlin"); Clock clock = Clock.system(zone); Getting human date and time Working with a time represented in a single long variable is not what we wanted. We want to work with objects that represent human readable time. The LocalDate, LocalTime and LocalDateTime classes do just that. import javax.time.LocalDate; // The now() method returns the current DateTime LocalDate date = LocalDate.now(); System.out.printf("%s-%s-%s", date.getYear(), date.getMonthValue(), date.getDayOfMonth() ); Using LocalDate to print the current date Doing calculations with times and dates One of the most important functionalities of JSR-310 is that you can do calculations with dates and times. The API makes it very easy to do that. import javax.time.LocalTime; import javax.time.Period; import static javax.time.calendrical.LocalPeriodUnit.HOURS; Period p = Period.of(5, HOURS); LocalTime time = LocalTime.now(); LocalTime newTime; newTime = time.plus(5, HOURS); // or newTime = time.plusHours(5); // or newTime = time.plus(p); Three ways of adding 5 hours to the current time Each class that represents human time implements the AdjustableDateTime interface. The interface requires the plus and the minus method that take a value and a PeriodUnit as argument. Conclusion This article gave a (very) brief introduction into the new date and time API that will ship with Java 8. The API seems to be very consistent and well thought through and provides many ways to interact with dates and times. Upon release of Java 8 the API will be moved from the javax.time package over to java.time, so there will be no conflict if you start using the current implementation.
September 25, 2012
by Fabian Becker
· 78,689 Views
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Understanding Enterprise Integration Patterns
First of all we should define EIPs and why we should use them. As the name implies, these are tested solutions for specific design problems encountered during many years in the development of IT systems. And what is all the more important is that they are technology-agnostic which means it does not matter what programming language or operating system you use. Patterns are divided into seven sections: 1. Messaging Systems, 2. Messaging Channels, 3. Message Constructions, 4. Message Routing, 5. Message Transformation, 6. Messaging endpoints, 7. System management. The purpose of this article is to encourage you to use the patterns so I will discuss briefly only one or two such patterns from each of above sections. If you want to explore then further, visit http://www.eaipatterns.com/ or read Gregor Hohpe’s book mentioned in the introduction of this series. Message Channel (from Messaging Systems) A message channel is a logical channel which is used to connect the applications. One application writes messages to the channel and the other one (or others) reads that message from the channel. Message queue and message topic are examples of message channels. Message Translator (from Messaging Systems) Message translator transforms messages in one format to another. For example one application sends a message in XML format, but the other accepts only JSON messages so one of the parties (or mediator) has to transform XML data to JSON. This is probably the most widely used integration pattern. Publish-Subscribe Channel (from Messaging Channels) This type of channel broadcasts an event or notification to all subscribed receivers. This is in contrast with a point-to-point channel . Each subscriber receive the message once and next copy of this message is deleted from channel. The most common implementation of this patter is messaging topic. Dead Letter Channel (from Messaging Channels) The Dead Letter Channel describe scenario, what to do if the messaging system determines that it cannot deliver a message to the specified recipient. This may be caused for example by connection problems or other exception like overflowed memory or disc space. Usually, before sending the message to the Dead Letter Channel, multiple attempts to redeliver message are taken. Correlation Identifier (from Message Construction) Correlation Identifier gives the possibility to match request and reply message when asynchronous messaging system is used. This is usually accomplished in the following way: Producer: Generate unique correlation identifier. Producer: Send message with attached generated correlation identifier. Consumer: Process messages and send reply with attached correlation identifier given in request message. Producer: Correlate request and reply message based on correlation identifier. Content-Based Router (from Message Routing) Content-Based Router examines message contents and route messages based on data contained in the message. Content Enricher (from Message Transformation) Content Enricher as the name suggests enrich message with missing information. Usually external data source like database or web service is used. Event-Driven Consumer (from Messaging Endpoints) Event-Driver Consumer enables you to provide a action that is called automatically by the messaging channel or transport layer. It is asynchronous type of pattern because receiver does not have a running thread until a callback thread delivers a message. Polling Consumer (from Messaging Endpoints) Polling Consumer is used when we want receiver to poll for a message, process it and next poll for another. What is very important is that this pattern is synchronous because it blocks thread until a message is received. This is in contrast with a event-driven consumer. An example of using this pattern is file polling. Wire Tap (from System Management) Wire Tap copy a message and route it to a separate channel, while the original message is forwarded to the destination channel. Usually Wire Tap is used to inspect message or for analysis purposes.
September 20, 2012
by Michał Warecki
· 76,281 Views · 23 Likes
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How To Create A Theme Options Page For WordPress
If you have ever used a WordPress premium theme then you would of seen the custom theme options page that is available. The theme options page that is found under the appearance menu which allows the admin of the WordPress site to change some of the settings on the theme. Most premium themes will come with options to change the colors of fonts, backgrounds, change images or font types...anything that allows you to style the WordPress theme. Some of the most common fields to change are: Theme Options - To edit the theme logo, change the stylesheet, upload a new favicon, Add Google analytics code, enter your feedburner URL and add custom CSS. Styling Options - Change the background colour or change the background image. Fonts - Change the font on all your header tags or the main content text. Social - Providing you theme with your social media profiles will make it easier to link to them in parts of your theme or display your latest tweets. Option pages can also be used on plugins to change settings and to customize the plugin. Examples Of Theme Options Pages Here is what some of the theme options page from premium themes look like. How To Build A Theme Option Page When creating an option page there are a few things you need to setup. Add Menu - If you want to display the menu under the appearance menu or if you want to give the options page it's own menu. Add Sections - These are sections of settings you are adding to the options page. Register Settings - Settings are the different fields you are adding to the options page, they need to be registered with the settings API. Display Settings - The settings API will be used to call a function to display the setting. Validate Setting - When the user saves the settings field the input will need to be validated before stored in the options table. Feedback Messages - When the settings are saved you need to be able to feedback to the user if the settings were saved successfully or if there was an error during validation. To help us perform all these tasks there is a WordPress API called the Settings API. This API allows admin pages to handle setting forms semi-automatically. With the API you can define pages for the settings, sections for the settings and fields for the settings. This works by registering setting fields to be displayed within sections and page will display these sections. WordPress uses the Settings API by default on existing admin pages, this means that by using the Settings API you can add to existing pages by registering new settings. All validation must be performed by the developer of the settings pages but the Settings API will control the creation of the form and storing the values in the form in the options table. Add Menu To WordPress Admin When adding a menu to the WordPress admin screen you have loads of flexibility you have the option of adding brand new menu items or adding the menu as a sub menu. To add a top level menu just use the following function add_menu_page(). $page_title - The title used on the settings page. $menu_title - The title used on the menu. $capability - Only displays the menu if the user matches this capability. $menu_slug - The unique name of the menu slug. $function - This is the callback function to run to display the page. $icon_url - Display a icon just for the menu. $position - This allows you to choose when the menu item appears in the list. If you prefer to have the menu under the appearance parent menu you can use the following code snippet. Or you can use the function add_theme_page() which will add a sub-menu under the appearance menu. add_theme_page( $page_title, $menu_title, $capability, $menu_slug, $function); Registering The Settings To start off we need to register the settings group we are going to store the settings page values. This will use the Settings API to define the group of settings, we will then add the settings to a group. When you store the settings in this group they are stored in the wp_options database table so you can get these values out at a later date. The wp_options table is a key value pairing stored in the database. This is what you should use when storing long term data on your WordPress site. If you are storing a lot of data it's best practice to turn the data into an array and store it under one key, instead of storing all the values over multiple keys. This means that if you have a settings page to change the site logo, background color, font, font size etc, you won't have an option for each of these but you will group them into an option group. The reason you do this is to increase on database efficiency by not adding too many rows to the options database. To register settings on the Settings API you need to use the function register_setting(). The parameters you pass into this are: Option Group - The name of the group of settings you are going to store. This must match the group name used in the settings_field() function. Option name - The name of the option which will be saved, this is the key that is used in the options table. Sanitize Callback - This is the function that is used to validate the settings for this option group. Add Sections To Settings Once the settings are registered we can add section groups to the Settings API. This will allow us to organise the settings on the page, so that you can add styles to display these differently on the page. The benefit of adding sections on your Settings API is so that we can call the function do_settings_sections() as this will display all the settings under this one section. To create you own settings all you have to do is use the function add_settings_section(). The parameters you need to use on this function are: Id - String to use for the ID of the section. Title - The title to use on the section. Callback - This is the function that will display the settings on the page. Page - This is the page that is displaying the section, should match the menu slug of the page. Add Fields To The Sections The last important function we need to use to add settings to the page is the add_settings_field() function, this is used as part of the Settings API to define fields to a section. The function will need to know the page slug and the section Id before you can define the settings to use. All the settings which you setup here will be stored in the options table under the key used in the register_settings() function. To use this function you need to add the following parameters. ID - ID of the field Title - Title of the field. Callback - Function used to display the setting. This is very important as it is used to display the input field you want. Page - Page which is going to display the field should be the same as the menu slug on the section. Section - Section Id which the field will be added to. $args - Additional arguments which are passed to the callback function. Example Of Using The Settings API There is a lot of information to take in above to create this settings page so it can seem a bit complicated but once you get your head around the structure the Settings API uses it's actually quite easy to understand. The best way to understand how this all works is to show you with an example. Create A Theme Option Page With A Textbox Field In this example we will create a theme option page and add a textbox on the page to add additional text to the index.php. Just add the following to your functions.php file to create a theme options page. First we start off by creating the menu item under the appearance menu by using the add_theme_page() function on the admin_menu action. /** * Theme Option Page Example */ function pu_theme_menu() { add_theme_page( 'Theme Option', 'Theme Options', 'manage_options', 'pu_theme_options.php', 'pu_theme_page'); } add_action('admin_menu', 'pu_theme_menu'); As you can see above we set the callback function to the theme options page to be pu_theme_page so we need to create this function to display our page. Here we create a form to submit to the options.php so that we can save in the options table, we call settings_fields() to the get the settings in register_settings() and use the do_settings_sections() function to display our settings. /** * Callback function to the add_theme_page * Will display the theme options page */ function pu_theme_page() { ?> Custom Theme Options Created by Paulund. 'text', 'id' => 'pu_textbox', 'name' => 'pu_textbox', 'desc' => 'Example of textbox description', 'std' => '', 'label_for' => 'pu_textbox', 'class' => 'css_class' ); add_settings_field( 'example_textbox', 'Example Textbox', 'pu_display_setting', 'pu_theme_options.php', 'pu_text_section', $field_args ); } The callback function on creating sections can be used to add addition information that will appear above every section, on this example we are just leaving it blank. /** * Function to add extra text to display on each section */ function pu_display_section($section){ } The callback function on the add_settings_field() function is pu_display_setting, this is the function that is going to echo the display of any input's on the page. The parameter to this function is the $args value on the add_settings_field() we can use this to add things like id, name, default value etc. We want to get any existing values from the wp_option table to display any values which previously typed in by the user, do to this we get the values from the table by using the get_option() function. /** * Function to display the settings on the page * This is setup to be expandable by using a switch on the type variable. * In future you can add multiple types to be display from this function, * Such as checkboxes, select boxes, file upload boxes etc. */ function pu_display_setting($args) { extract( $args ); $option_name = 'pu_theme_options'; $options = get_option( $option_name ); switch ( $type ) { case 'text': $options[$id] = stripslashes($options[$id]); $options[$id] = esc_attr( $options[$id]); echo ""; echo ($desc != '') ? "$desc" : ""; break; } } Finally we can validate the values added to the form by creating the validation callback function pu_validate_settings. All this does at the moment is loop through the inputs passed to it and checks if it's a letter or a number. The return of this function is what will be added to the database. /** * Callback function to the register_settings function will pass through an input variable * You can then validate the values and the return variable will be the values stored in the database. */ function pu_validate_settings($input) { foreach($input as $k => $v) { $newinput[$k] = trim($v); // Check the input is a letter or a number if(!preg_match('/^[A-Z0-9 _]*$/i', $v)) { $newinput[$k] = ''; } } return $newinput; } If you copy all the snippets above into your functions.php file you will see this options form under the appearance menu. Using Theme Options Within Your Theme Now that you understand how to create a theme options page you need to be able to use this value in your theme so you can change the settings. All the settings are stored in the wp_options table with WordPress it's very easy to get these values out all you have to do is use the get_option() function. The option name is the name you put on the register_settings() function. So in our example above you will use this code. The $options variable will now store an array of the values from the theme options, which you can display the value of the textbox we put on the page by using this snippet. Conclusion That's the basics that you need to understand to use the Settings API, now you can take this information and create your own theme options page. Experiment with different input types you can add to the form, experiment with different validation methods you want to use. In future tutorials I will post how you can use some of the inbuilt WordPress third party applications to create a better user experience on your theme options panel. This will include things like color pickers, date pickers, jQuery UI features etc. As you can see we have created a settings option page in just over 100 lines of code, so it's not a hard thing to do but that are a few steps to it and the features can be expanded on. For this reason people have created theme option frameworks to allow you to easily create a theme option page with much higher level of complexity with the options. But like many other frameworks I always recommend you learn the basics before using a framework, this is why it's important to understand how the Settings API works before using or creating a settings page framework.
September 18, 2012
by Paul Underwood
· 23,795 Views
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Getting Started: Apache Camel Using Groovy
From their site, it says the Apache Camel is a versatile open-source integration framework based on known Enterprise Integration Patterns. It might seem like a vague definition, but I want to tell you that this is a very productive Java library that can solve many of typical IT problems! You can think of it as a very light weight ESB framework with "batteries" included. In every jobs I've been to so far, folks are writing their own solutions in one way or another to solve many common problems (or they would buy some very expensive enterprisy ESB servers that takes months and months to learn, config, and maintain). Things that we commonly solve are integration (glue) code of existing business services together, process data in a certain workflow manner, or move and transform data from one place to another etc. These are very typical need in many IT environments. The Apache Camel can be used in cases like these; not only that, but also in a very productive and effective way! In this article, I will show you how to get started with Apache Camel along with just few lines of Groovy script. You can certainly also start off with a full Java project to try out Camel, but I find Groovy will give you the shortest working example and learning curve. Getting started with Apache Camel using Groovy So let's begin. First let's see a hello world demo with Camel + Groovy. @Grab('org.apache.camel:camel-core:2.10.0') @Grab('org.slf4j:slf4j-simple:1.6.6') import org.apache.camel.* import org.apache.camel.impl.* import org.apache.camel.builder.* def camelContext = new DefaultCamelContext() camelContext.addRoutes(new RouteBuilder() { def void configure() { from("timer://jdkTimer?period=3000") .to("log://camelLogger?level=INFO") } }) camelContext.start() addShutdownHook{ camelContext.stop() } synchronized(this){ this.wait() } Save above into a file named helloCamel.groovy and then run it like this: $ groovy helloCamel.groovy 388 [main] INFO org.apache.camel.impl.DefaultCamelContext - Apache Camel 2.10.0 (CamelContext: camel-1) is starting 445 [main] INFO org.apache.camel.management.ManagementStrategyFactory - JMX enabled. 447 [main] INFO org.apache.camel.management.DefaultManagementLifecycleStrategy - StatisticsLevel at All so enabling load performance statistics 678 [main] INFO org.apache.camel.impl.converter.DefaultTypeConverter - Loaded 170 type converters 882 [main] INFO org.apache.camel.impl.DefaultCamelContext - Route: route1 started and consuming from: Endpoint[timer://jdkTimer?period=3000] 883 [main] INFO org.apache.camel.impl.DefaultCamelContext - Total 1 routes, of which 1 is started. 887 [main] INFO org.apache.camel.impl.DefaultCamelContext - Apache Camel 2.10.0 (CamelContext: camel-1) started in 0.496 seconds 898 [Camel (camel-1) thread #1 - timer://jdkTimer] INFO camelLogger - Exchange[ExchangePattern:InOnly, BodyType:null, Body:[Body is null]] 3884 [Camel (camel-1) thread #1 - timer://jdkTimer] INFO camelLogger - Exchange[ExchangePattern:InOnly, BodyType:null, Body:[Body is null]] 6884 [Camel (camel-1) thread #1 - timer://jdkTimer] INFO camelLogger - Exchange[ExchangePattern:InOnly, BodyType:null, Body:[Body is null]] ... The little script above is simple but it presented few key features of Camel Groovyness. The first and last section of the helloCamel.groovy script are just Groovy featuers. The @Grab annotation will automatically download the dependency jars you specify. We import Java packages to use its classes later. At the end we ensure to shutdown Camel before exiting JVM through the Java Shutdown Hook mechanism. The program will sit and wait until user press CTRL+C, just as a typical server process behavior. The middle section is where the Camel action is. You would always create a Camel context to begin (think of it as the server or manager for the process.) And then you would add a Camel route (think of it as a workflow or pipeflow) that you like to process data (Camel likes to call these data "messages"). The route consists of a "from" starting point (where data generated), and one or more "to" points (where data going to be processed). Camel calls these destination 'points' as 'Endpoints'. These endpoints can be expressed in simple URI string format such as "timer://jdkTimer?period=3000". Here we are generating timer message in every 3 secs into the pipeflow, and then process by a logger URI, which will simply print to console output. After Camel context started, it will start processing data through the workflow, as you can observe from the output example above. Now try pressing CTRL+C to end its process. Notice how the Camel will shutdown everything very gracefully. 7312 [Thread-2] INFO org.apache.camel.impl.DefaultCamelContext - Apache Camel 2.10.0 (CamelContext: camel-1) is shutting down 7312 [Thread-2] INFO org.apache.camel.impl.DefaultShutdownStrategy - Starting to graceful shutdown 1 routes (timeout 300 seconds) 7317 [Camel (camel-1) thread #2 - ShutdownTask] INFO org.apache.camel.impl.DefaultShutdownStrategy - Route: route1 shutdown complete, was consuming from: Endpoint[timer://jdkTimer?period=3000] 7317 [Thread-2] INFO org.apache.camel.impl.DefaultShutdownStrategy - Graceful shutdown of 1 routes completed in 0 seconds 7321 [Thread-2] INFO org.apache.camel.impl.converter.DefaultTypeConverter - TypeConverterRegistry utilization[attempts=2, hits=2, misses=0, failures=0] mappings[total=170, misses=0] 7322 [Thread-2] INFO org.apache.camel.impl.DefaultCamelContext - Apache Camel 2.10.0 (CamelContext: camel-1) is shutdown in 0.010 seconds. Uptime 7.053 seconds. So that's our first taste of Camel ride! However, we titled this section as "Hello World!" demo, and yet we haven't seen any. But you might have also noticed that above script are mostly boiler plate code that we setup. No user logic has been added yet. Not even the logging the message part! We simply configuring the route. Now let's modify the script little bit so we will actually add our user logic to process the timer message. @Grab('org.apache.camel:camel-core:2.10.0') @Grab('org.slf4j:slf4j-simple:1.6.6') import org.apache.camel.* import org.apache.camel.impl.* import org.apache.camel.builder.* def camelContext = new DefaultCamelContext() camelContext.addRoutes(new RouteBuilder() { def void configure() { from("timer://jdkTimer?period=3000") .to("log://camelLogger?level=INFO") .process(new Processor() { def void process(Exchange exchange) { println("Hello World!") } }) } }) camelContext.start() addShutdownHook{ camelContext.stop() } synchronized(this){ this.wait() } Notice how I can simply append the process code part right after the to("log...") line. I have added a "processor" code block to process the timer message. The logic is simple: we greet the world on each tick. Making Camel route more concise and practical Now, do I have you at Hello yet? If not, then I hope you will be patient and continue to follow along for few more practical features of Camel. First, if you were to put Camel in real use, I would recommend you setup your business logic separately from the workflow route definition. This is so that you can clearly express and see your entire pipeflow of route at a glance. To do this, you want to move the "processor", into a service bean. @Grab('org.apache.camel:camel-core:2.10.0') @Grab('org.slf4j:slf4j-simple:1.6.6') import org.apache.camel.* import org.apache.camel.impl.* import org.apache.camel.builder.* import org.apache.camel.util.jndi.* class SystemInfoService { def void run() { println("Hello World!") } } def jndiContext = new JndiContext(); jndiContext.bind("systemInfoPoller", new SystemInfoService()) def camelContext = new DefaultCamelContext(jndiContext) camelContext.addRoutes(new RouteBuilder() { def void configure() { from("timer://jdkTimer?period=3000") .to("log://camelLogger?level=INFO") .to("bean://systemInfoPoller?method=run") } }) camelContext.start() addShutdownHook{ camelContext.stop() } synchronized(this){ this.wait() } Now, see how compact this workflow route has become? The Camel's Java DSL such as "from().to().to()" for defining route are so clean and simple to use. You can even show this code snip to your Business Analysts, and they would likely be able to verify your business flow easily! Wouldn't that alone worth a million dollars? How about another demo: FilePoller Processing File polling processing is a very common and effective way to solve many business problems. If you work for commercial companies long enough, you might have written one before. A typical file poller would process incoming files from a directory and then process the content, and then move the file into a output directory. Let's make a Camel route to do just that. @Grab('org.apache.camel:camel-core:2.10.0') @Grab('org.slf4j:slf4j-simple:1.6.6') import org.apache.camel.* import org.apache.camel.impl.* import org.apache.camel.builder.* import org.apache.camel.util.jndi.* class UpperCaseTextService { def String transform(String text) { return text.toUpperCase() } } def jndiContext = new JndiContext(); jndiContext.bind("upperCaseTextService", new UpperCaseTextService()) def dataDir = "/${System.properties['user.home']}/test/file-poller-demo" def camelContext = new DefaultCamelContext(jndiContext) camelContext.addRoutes(new RouteBuilder() { def void configure() { from("file://${dataDir}/in") .to("log://camelLogger") .to("bean://upperCaseTextService?method=transform") .to("file://${dataDir}/out") } }) camelContext.start() addShutdownHook{ camelContext.stop() } synchronized(this){ this.wait() } Here you see I defined a route to poll a $HOME/test/file-poller-demo/in directory for text files. Once it's found it will log it to console, and then process by a service that transform the content text into upper case. After this, it will send the file into $HOME/test/file-poller-demo/out directory. My goodness, reading the Camel route above probably express what I wrote down just as effective. Do you see the benefits here? What's the "batteries" included part. If you've used Python programming before, you might have heard the pharase that they claim often: Python has "batteries" included. This means their interpreter comes with a rich of libaries for most of the common programming need. You can often write python program without have to download separated external libraries. I am making similar analogies here with Apache Camel. The Camel project comes with so many ready to use components that you can find just about any transport protocals that can carry data. These Camel "components" are ones that support different 'Endpoint URI' that we have seen in our demos above. We have simply shown you timer, log, bean, and file components, but there are over 120 more. You will find jms, http, ftp, cfx, or tcp just to name a few. The Camel project also has an option for you to define route in declarative xml format. The xml is just an extension of a Spring xml config with Camel's namespace handler added on top. Spring is optional in Camel, but you can use it together in a very powerful way.
September 10, 2012
by Zemian Deng
· 15,750 Views · 1 Like
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How to Deploy a war File Using GlassFish
Before trying this out make sure you have installed GlassFish in your machine. Installation is just easy as downloading the zip archive from here and unzipping it to a desired location. Creating a new domain Open up a terminal, change directory to the GlassFish installation directory and run following. bin/asadmin This will enable you to use asadmin tool. Now execute the following command to create a new domain. after running this command you will probably have to give admin password and master password. create-domain --adminport 5000 --profile developer --user admin domain2 Now open up another terminal and change directory to [glassfish-installation]/domains/ and you will see the newly created domain2 has appeared there. Open up a browser and go to http://localhost:5000/. This will bring you the GlassFish GUI admin console. This is one place you can deploy your war file. But in this post I'm not much focusing on it, instead I will show you how to do this using the command line. But GUI lovers, for any consolation I have put some screenshots which you can follow if you prefer the GUI way. In case you want to delete a domain use the following command. delete-domain domain2 Starting the domain To start domain2 run following command. start-domain domain2 Deploying a war file Use the following command to deploy your war file. deploy --port 5000 --host localhost /home/pavithra/workspace/NewDemoService/WebServicesJaxWs/NewDemoService.war After deploying the war file I can access the WSDL file I want to access using the URL http://localhost:8080/NewDemoService/NewDemoService?WSDL To change default 8080 (HTTP) port which specifies where the web application context roots are available for a Web browser to connect to, you can use the --instanceport parameter when creating the domain. See the following command. create-domain --adminport 5000 --profile developer --user admin --instanceport 9000 domain2 Undeploying a war file To undeploy NewDemoService.war file you need to use the following command. Note that here you don't have to use the full name but literal "NewDemoService". undeploy --port 5000 --host localhost NewDemoService Stopping a domain To stop the domain "domain2" use the following command. stop-domain domain2 After this if you try to deploy to this particular domain, it will complain. Auto Deploy To perform auto deploy, copy NewDemoService.war file in to [glassfish-installation-directory]/domains/domain2/autodeploy directory. If autodeploy succeeds, you will see NewDemoService.war_deployed has created. This will deploy your war file automatically.
September 10, 2012
by Pavithra Gunasekara
· 62,163 Views
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Removing Blank Lines in Eclipse
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:-)
September 7, 2012
by Erich Styger
· 37,928 Views · 2 Likes
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Building A Simple API Proxy Server with PHP
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 .
September 2, 2012
by Gonzalo Ayuso
· 20,480 Views
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Password Encryption -- Short Answer: Don't.
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.
August 28, 2012
by Steven Lott
· 21,953 Views
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Organize Imports in Eclipse
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.
August 28, 2012
by Veera Sundar
· 47,034 Views · 3 Likes
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Spring Data, Spring Security and Envers integration
Learn about pros, cons, and basics of Spring security and data, plus Envers integration.
August 20, 2012
by Nicolas Fränkel
· 25,163 Views · 1 Like
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Spring Integration with Gateways
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.
August 13, 2012
by Partha Bhattacharjee
· 60,191 Views
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Gradle Plugin for NetBeans IDE 7.2
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
August 12, 2012
by Attila Kelemen
· 11,365 Views
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Switching Source Files in the Eclipse Editor (CTRL+TAB)
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
August 11, 2012
by Erich Styger
· 8,995 Views · 1 Like
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Using Multiple Versions of JDK and Eclipse in Single Machine
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).
August 4, 2012
by Veera Sundar
· 20,924 Views
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Eclipse Full Screen Mode Plugin
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
July 26, 2012
by Erich Styger
· 24,006 Views · 1 Like
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Hide and Show Eclipse Toolbar
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
July 20, 2012
by Erich Styger
· 17,960 Views
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20 Subjects Every Software Engineer Should Know
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.
July 2, 2012
by Cagdas Basaraner
· 108,791 Views · 5 Likes
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HTML5 Geolocation API to Measure Speed and Heading of Your Car
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.
July 1, 2012
by Jos Dirksen
· 16,564 Views
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Apache Camel Monitoring
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...
June 27, 2012
by Ben O'Day
· 20,202 Views
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