What are Java command line options to set to allow JVM to be remotely debugged?

java debugging
paulgreg picture paulgreg · Sep 26, 2008 · Viewed 410.8k times · Source

I know there's some JAVA_OPTS to set to remotely debug a Java program.

What are they and what do they mean ?

Answer

paulgreg picture paulgreg · Oct 6, 2008

Before Java 5.0, use -Xdebug and -Xrunjdwp arguments. These options will still work in later versions, but it will run in interpreted mode instead of JIT, which will be slower.

From Java 5.0, it is better to use the -agentlib:jdwp single option:

-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=1044

Options on -Xrunjdwp or agentlib:jdwp arguments are :

  • transport=dt_socket : means the way used to connect to JVM (socket is a good choice, it can be used to debug a distant computer)
  • address=8000 : TCP/IP port exposed, to connect from the debugger,
  • suspend=y : if 'y', tell the JVM to wait until debugger is attached to begin execution, otherwise (if 'n'), starts execution right away.

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