java/shellscript code to find out if a jar file is already running on current machine

Question

How do I find out if a specific JAR file is running on my machine or not? I just want to ensure that a specific JAR is only executed once at any time-- so if another request

Answer 1

Try to create a new jar,

create a class inside with like this (not yet functional code, just a scribble):

static ServerSocket unicorn;
public void load(){
    unicorn=new ServerSocket(39483); // whatever-port

    URLClassLoader myloader = new URLClassLoader(new URL[]{this.getClass().getResource("/META-INF/specific.jar")});
    ... // do all your unique stuff
    Runtime.addShutdownHook(new Runnable(){unicorn.close();})
}

Place your specific.jar inside the new.jar. If ever another instance of this jar try to be load, a exception will be thrown: Socket already in use.