Eclipse, Maven, Java Rebel, and Hot Swap/Deployment

Hot Swap:
The ability to load the .class files dynamically at run-time

Hot Deployment:
The ability to deploy the .class files in Application/Web server at run-time

How do you do it?
Many solutions and no silver bullet yet!

One such solution follows....



Tools you need:

1. Eclipse (tested with Ver. 3.4). Ensure WTP is installed
2. FileSync eclipse plugin
   Download and install from http://andrei.gmxhome.de/filesync/index.html
3. JBoss-Tools eclipse plugin
   Download and install from http://www.jboss.org/tools/download
   We need to configure JBoss server within Eclipse. The one provided by WTP is not advanced enough.
4. Maven/Ant (if your project uses it)
   Any conventional directory structure is fine
5. Java-Rebel .jar (license required)
   Download Trial version from http://www.zeroturnaround.com/javarebel/download/

The Key Enabler (...with some limitations):

• Java Rebel provides a seamless solution to a good extent
• Has an Annual license of $59/user
• EXPLORE: http://www.zeroturnaround.com/javarebel/
• BUY: http://sales.zeroturnaround.com/

The website also lists the comparison here.

Configuration Steps:

1. Ensure all the plugins are installed
2. Ensure eclipse is using JDK as Java runtime
3. Enable JBoss Server View
4. Configure JBoss Server ...including Java-Rebel settings
5. Checkout code using SVN and create your default Java project. Assuming Maven structure, build once using console and charge-up your local .m2 repository
6. Create empty eclipse WTP Dynamic Web Project
7. Link src and resources folder in WTP_Project to the above Maven-Java project
8. Copy ‘lib’ folder from ear/target folder into WEB-INF/lib in WTP project
9. FileSync web/src/main/webapp to WTP_Project/WebContent folder
10. Set output path for your WTP_Project as WEB-INF/classes
11. Fire up your server from within Eclipse
12. Any code changes you’ll make are in your Maven project
    

JBoss Server View settings:

1. Automatically publish set to 0 sec
2. Server start timeout increased >300s
3. Custom Deploy directories
4. JMX admin password

JBoss Launch Configuration VM arguments in JBoss Server View:

Dprogram.name="JBossTools JBoss 4.0 Runtime" -Xms256m -Xmx512m -XX:MaxPermSize=256m -Dsun.rmi.dgc.client.gcInterval=3600000 -Dsun.rmi.dgc.server.gcInterval=3600000 -Djava.endorsed.dirs="C:/NOSCAN/jboss-4.0.5/lib/endorsed" -noverify -javaagent:C:/javarebel-2.0/javarebel.jar -Drebel.spring_plugin=true -Drebel.aspectj_plugin=true

The BOTTOM LINE

• No ‘build’ segment
  ◦Code in Eclipse is always “Build Automatically”
• No ‘deploy’ segment
  ◦If you abide by the Java-rebel capabilities
• Rapid feedback (including Spring IoC)
  ◦All spring layers (controller, command, dao, Beans)
• Original code base not affected by Eclipse WTP project
• Occasional restart of Jboss within Eclipse, when
  ◦Redefining Interface
  ◦Updating ‘static’ block
• No JBoss Crashing in Eclipse with JBoss Tools plugin…so far.

ENJOY.....and smart coding...