Re: Adding a timeout to commands by wrapping + thread - suggestions?

Well, I have refined the example a bit, but have a new problem:
Exceptions from the thread...

If I wrap a command in a Runnable, it might throw a (runtime)
exception. Apparently such exceptions are only reported, but not
passed on to the calling thread.

I can catch them using an implementation of ThreadGroup that
implements uncaughtException, but re-throwing does not propagate to
the main thread either.

The code below outputs:
Caught exception - throwing a new one
Command was executed just fine

....where I had hoped it would instead die with an exception before
printing "Command was executed just fine".

-- code --

public class OnTimeoutExecuteCmd implements Command {

    private Command wrappedCmd;

    private Command onTimeoutCmd;

    private long timeoutL;

    public OnTimeoutExecuteCmd(Command wrappedCmd, Command
onTimeoutCmd, long timeoutL) {
        this.wrappedCmd = wrappedCmd;
        this.onTimeoutCmd = onTimeoutCmd;
        this.timeoutL = timeoutL;
    }

    static class OverrideThreadGroup extends ThreadGroup {

        public OverrideThreadGroup() {
            super("Re-throw RTE");
        }

        public void uncaughtException(Thread t, Throwable e) {
            System.out.println("Caught exception - throwing a new
one");
            throw new RuntimeException("Uncaught exception from
thread", e);
        }

    }

    public void execute() {
        Thread cmdThread = new Thread(new
CommandRunnable(wrappedCmd));
        cmdThread.setUncaughtExceptionHandler(new
OverrideThreadGroup());
        cmdThread.start();
        try {
            cmdThread.join(timeoutL);
        } catch (InterruptedException e) {
            throw new RuntimeException(
            "I was interrupted while waiting for encapsulated command
to "
            + "join or timeout to expire");
        }
        if (cmdThread.isAlive()) {
            onTimeoutCmd.execute();
        }
        try {
            cmdThread.join();
        } catch (InterruptedException e) {
            throw new RuntimeException(
                "I was interrupted while waiting for encapsulated
command to join");
        }
    }

}

public class ThrowingCmd implements Command {

    public void execute() {
        System.out.println("Throwing now");
        throw new RuntimeException("I threw in the towel");

    }

}

public class TestOnTimeout {

    public static void main(String[] args) {
        Command ote = new OnTimeoutExecuteCmd(new ThrowingCmd(), new
HelloCmd(), 800L);
        try {
            ote.execute();
            System.out.println("Command was executed just fine");
        } catch (RuntimeException e) {
            System.err.println("Runtime exception from ote");
        }
    }

}