How to use FutureTask (with example) ?

Steps of using FutureTask
  1. Define FutureTask and Callable implementation
  2. Provide Callable object in FutureTask constructor
  3. Create a thread and provide FutureTask object in its constructor
  4. Start the thread
  5. Use FutureTask using FutureTask.get() to get the data
  6. Handle ExecutionException


Example
public class DataLoader {
  // Create new object FutureTask with return type as generic  // Create new Callable object (+ implement call method)   // and pass it to FutureTask constructor  FutureTask future = new FutureTask<UserInfo> (
      new Callable<UserInfo>() {
            public UserInfo call() throws UserDataException {
                  return loadData();
            }
      });

   // Define a thread using FutureTask
   private Thread thread = new Thread(future);
   // Start the thread
   public void start() { thread.start(); }

  public UserInfo getData() throws UserDataException, ExecutionException {
    // Call FutureTask.get to load the data and handle ExecutionException
       try {
       return future.get();
   } catch (ExecutionException e) {
       Throwable cause = e.getCause();
       if (cause instanceof UserDataException)
          throw (UserDataException) cause;
       else
          throw e;       }
 }

}