创建一个新的事件处理程序和源代码

这是一个相当普遍的要求，因为您通常希望尽可能少地在UI线程上进行操作。

如果您正在使用秋千，请看SwingWorker课程。如果你不使用秋千，你可能想看看ExecutorService和FutureTask。

import java.util.concurrent.Callable; 
import java.util.concurrent.ExecutionException; 
import java.util.concurrent.ExecutorService; 
import java.util.concurrent.Executors; 
import java.util.concurrent.FutureTask; 
public class Futures { 
    public static void main(String[] args) { 
     UI ui = new UI(); 
     FutureHandle<String> handle = new FutureHandle<String>(new BigJob()); 
     FutureHandle<String> handle2 = new FutureHandle<String>(new BigJob()); 
     ui.doUIStuff("Things can happen on the UI thread"); 
     ui.startHeavyLiftingJob(handle); 
     ui.doUIStuff("I've got a big job running, but I'm still responsive"); 
     ui.startHeavyLiftingJob(handle2); 
    } 
    /** 
    * Your UI class. Don't want to do anything big 
    * on the UI's thread. 
    */ 
    static class UI implements Listener<String> { 
     private ExecutorService threadPool = Executors.newFixedThreadPool(5); 
     public void doUIStuff(String msg) { 
      System.out.println(msg); 
     } 
     public void startHeavyLiftingJob(FutureHandle<String> handle) { 
      System.out.println("Starting background task"); 
      handle.setListener(this); 
      threadPool.execute(handle); 
     } 
     public void callback(String result) { 
      System.out.println("Ooh, result ready: " + result); 
     } 
    } 
    /** 
    * A handle on a future which makes a callback to a listener 
    * when the callable task is done. 
    */ 
    static class FutureHandle<V> extends FutureTask<V> { 
     private Listener<V> listener; 
     public FutureHandle(Callable<V> callable) { 
      super(callable); 
     } 
     @Override 
     protected void done() { 
      try { 
       listener.callback(get()); 
      } catch (InterruptedException e) { 
       //handle execution getting interrupted 
      } catch (ExecutionException e) { 
       //handle error in execution 
      } 
     } 
     public void setListener(Listener<V> listener) { 
      this.listener = listener; 
     } 
    } 
    /** 
    * Class that represents something you don't want to do on the UI thread. 
    */ 
    static class BigJob implements Callable<String> { 
     public String call() throws Exception { 
      Thread.sleep(2000); 
      return "big job has finished"; 
     } 
    } 
    interface Listener<V> { 
     public void callback(V result); 
    } 
}