Netbeans module development with JRebel

This post is mostly obsolete: See for an updated version.

In [project]\nbproject\ add the following line

run.args.extra=-J-noverify -J-javaagent:e:/tools/jrebel/jrebel.jar -J-Drebel.log=true


  • This requires a proper installation of jrebel in the path e:/tools/jrebel/
  • Do not forget to generate a rebel.xml into the root of your classpath
  • You have to compile the changed java source manually by Menu->Run->Compile file(“Compile-on-save” is not yet available for netbeans modules)
  • There will be some OSGI-exceptions when running/debugging the application, but class reloading works properly.

Tested with NetBeans IDE 7.1 RC2 (Build 201111302200)+7.1, JRebel 4.5.3

Other resources:

Update: You can also have a look at Javeleon

Update 2: In maven-based nbms you can run modules the following way (JRebel 4, 5)

  • enable “compile on save”
  • generate rebel.xml to /src/main using the context menu of jrebel (this way it will be copied to target/classes)
  • alter the properties-section of the pom.xml like this
            <>-J-noverify -J-javaagent:e:/tools/jrebel/jrebel.jar -J-Drebel.log=true ${}</>
  • run the module the normal way – you will accounter some osgi-exception as mentioned above
  • make changes to your classes and jrebel will pick it up like [207230] JRebel: Reloading class ''.
  • small issue: the jrebel-messages do not appear on the output-window – but in jrebel.log

Update 3:
@mkleint also blogged about JRebel and NBM-development at