JavaRebel with a Multi-module Enterprise Project in Maven

Question

Does anybody have experience working with JavaRebel, specifically for a large web application built using Maven? There is a JavaRebel plugin for Maven that seems under-documented, does anybody have comments on how it works, can you really update one class in a Multi-module Enterprise Project and have it "automagically" change on your Server?

Are there any issues with different IDEs and this setup? For example NetBeans will not let you compile one class at a time in a Maven project (from what I can tell).

Answer 1

Disclaimer: I work for ZeroTurnaround.

JRebel (formerly JavaRebel) installation involves the application configuration file "rebel.xml" and modifying the container startup command line.

The Maven plugin is used to generate the "rebel.xml" file, that is used by the JRebel agent running in the container to find the files in the workspace. This allows to use IDE building to compile .java files and skip the Maven build process, as the changes to files will be picked up from the workspace. However as it relies on the IDE to compile the classes, it does depend on the IDE ability to compile efficiently. I know for sure that Eclipse will compile classes one at a time and am fairly sure you can configure NetBeans and IntelliJ IDEA to do the same.

In addition to the Maven/rebel.xml configuration you also need to configure the container startup command line. You may also need to install and IDE plugin or do some additional configuration to have the best expirience with JRebel. Following through the steps of Installation manual ensures that.

Hope this helps.

Answer 2

Disclaimer: I've not actually used this plugin myself.

This tutorial implies that JavaRebel works well with Eclipse 3.4. If you are also using m2eclipse it should work ok with Maven projects as well (as long as you ensure that Maven and Eclipse are compiling to the same target folder so the Eclipse incremental compiler can be used to modify the class file).

According to this post, you should configure the javarebel-maven-plugin to generate the rebel.xml (used to mount external folders to the application classpath). There's also a general installation guide you may find useful.