Stopping a thread after a time

Question

Hi,
I'd like to be able to run a thread for a certain time and, based on it's state, then either run it for a longer time or suspend it. It'd be a bit awkward to do this in the thread itself, so I was thinking it'd be best to have another timer thread that interrupted it after n seconds. Unfortunately I'm not sure how to do this, despite a lot of searching.
Cheers,

Answer 1

You could try something like this ...
public class ThreadToThread {
  public static void main(String[] argv) {
    ThreadToThread ttt = new ThreadToThread();
    TempThread tt = ttt.new TempThread();
    tt.start();
    for (int i = 1; i < 11; i++) {
      try {
        Thread.sleep(5000);
        System.out.println("loop #"+i);
        if (tt.isDone())
          break;
      catch(InterruptedException ie) {
        System.out.println("In main: "+ie);
    if (!tt.isDone())
      tt.setDone();
    System.out.println("Done");
  class TempThread  extends Thread {
    boolean done;
    long    l;
    public void run() {
      while ( !done ) {
        doSomething();
    private void doSomething() {
      long   i = 0;
      double j = 0;
      System.out.println("In doSomething ... starting calculations ... ");
      for (; i < 50000000L; i++) {
        j = ((((j / 2.005) * .0075) % 10000.25) * Math.random()*10 * Math.sqrt(i));
      done = true;
      System.out.println("In TempThread ... done!");
    private boolean isDone() {
      return( done );
    private void setDone() {
      System.out.println("Setting done to true");
      done = true;
}