How can I debug applications under Java Web Start (JNLP)?

Question

I know how I can debug a remote Java VM with Eclipse, but how can I do it with a Java Web Start program. I have a problem that only occurs in Java Web Start. It must be security related.

I need a solution that will work with a current Java VM like 1.6.0_12.

Answer 1

It's quite the same like with any other Java process you want to debug remotely: You have to set up some arguments for the VM (-Xdebug -Xnoagent -Xrunjdwp:transport=dt_socket,server=n,suspend=y,address=12345 ) and then connect to the given port. In Java webstart 6.0 this can be done with the -J option, in earlier version via environment variable JAVAWS_VM_ARGS. See details here.

Answer 2

Start the JWS VM manually. This way you can provide the startup parameters to open the debug port. Here is a description, it goes like this:

set JAVAWS_TRACE_NATIVE=1 set JAVAWS_VM_ARGS="-Xdebug -Xnoagent -Djava.compiler=NONE -Xrunjdwp:transport=dt_socket,address=8989,server=y,suspend=n" javaws http://server:port/descriptor.jnlp