How to determine main class at runtime in threaded java application?

Question

I want to determine the class name where my application started, the one with the main() method, at runtime, but I'm in another thread and my stacktrace doesn't go all the way back to the original class.

I've searched System properties and everything that ClassLoader has to offer and come up with nothing. Is this information just not available?

Thanks.

Answer 1

See the comments on link given by Tom Hawtin. A solution is these days is (Oracle JVM only):

public static String getMainClassAndArgs() {     return System.getProperty("sun.java.command"); // like "org.x.y.Main arg1 arg2" } 

Tested only with Oracle Java 7. More information about special cases: https://bugs.java.com/bugdatabase/view_bug.do?bug_id=4827318

Answer 2

The JAVA_MAIN_CLASS environment value isn't always present depending on the platform. If you just want to get a name of the "main" class that started your Java process, you can do this:

  public static String getMainClassName()   {     StackTraceElement trace[] = Thread.currentThread().getStackTrace();     if (trace.length > 0) {       return trace[trace.length - 1].getClassName();     }     return "Unknown";   }