Question

How to run debugging session in Eclipse but to invoke it outside Eclipse (instead of doing Run->Debug I want to invoke some process (maybe jdb?) that will start debug in Eclipse). Is that possible?

Answer 1

As illustrated by this thread, it is possible through remote debugging (see remote debugging).
I.e: it won’t automatically launch Eclipse for you. You have to launch an Eclipse session and listen to the port used for remote debugging.

Well I just tried running a program from an Ant buildfile and then connected to it with Eclipse..worked great.
My test:

 <project default="remote">
  <target name="remote">

   <java classname="B" fork="true">
    <classpath>
     <pathelement path="bin" />
    </classpath>
    <jvmarg value="-Xdebug" />
    <jvmarg value="-Xnoagent" />
    <jvmarg value="-Djava.compiler=NONE" />
    <jvmarg
 value="-Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000" />
   </java>

  </target>
 </project>

I launched the Ant build outside Eclipse and tried with address=8000.
[…]. Also, since my app takes long to start I connected Eclipse pretty much after starting Ant. It shows some threads and picked up.