As long as you’re using a java application (ie an application calling your JVM), you can enable the debug mode with these parameters :
-Xdebug -Xrunjdwp:transport=dt_socket,address=8787,server=y,suspend=y
So for example, if you want to debug an ant launch (launched via « ant -f myBuild.xml » for example), you simply have to set ANT_OPTS; on windows :
set ANT_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,address=8787,server=y,suspend=y
Another example, with JBoss :
set JAVA_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,address=8787,server=y,suspend=y
and then you can debug your launch with Eclipse, for example, creating a new debug configuration (remote java application on port 8787) !
Option : you can choose whether or not the application should wait for your debugger setting suspend to y or n.
Update ! Make sure you use the same version of the JVM on both sides !(eclipse and the remote application launched in debug mode); for example if your application is started with a 64 bit JVM, your eclipse must use a 64 bits JVM also !