Sychronized Thread and return Help

Question

Hi I am fairly new to Java and I am a bit confused on how to carry out this Operation and I could do with a fee suggestions
I ve got a aa class Decoder that implements runnable and when called it outputs and array.
Where my problem is that I am not quite sure on how to return that array.I ve declared the ouput as public but I am a lil confused on where to stick get output to get back my results
Thanks for your help in advance
cheers
chib
class decoder implements runnable{
run()
do something
synchronized setinput()
synchronised getoutput()
}

Answer 1

Is it really a Thread you want to create? If you depend on the output of the calculation you should usually use a conventional method so that the caller will wait for the calculation to finish and use its results. If it really is a concurrent task, the result of which you need at some later time, use a class implementing Runnable, which holds the result with one of its fields:
public Decoder  implements Runnable {
  private InputType   in;
  private ReturnType  ret;
  private volatile boolean  done;
  public Decoder(InputType in) {
    this.in   = in;
    this.done = false;
  // not blocking test if done
  public boolean isDone()  { return  done; }
  // blocking request for return value
  public synchronized ReturnType getResult() {
    while(!done) try {
      wait();
    catch(InterruptedException e)  {}
    return  ret;
  public synchronized void run() {
    ret  = doCalc(in);  // some complex calculation
    done = true;
    notifyAll();