Platform.runLater(new Runnable() {
                        @Override
                        public void run() {
                            //更新JavaFX的主线程的代码放在此处
                            p.cancelProgressBar();
                        }
                    });

// 定义一个FutureTask，然后 Plateform.runLater() 这个futuretask
                        final FutureTask<String> query = new FutureTask<String>(new Callable<String>() {
                            @Override
                            public String call() throws Exception {
                                    // 新建一个窗口(方法中将创建stage)
                                    VcodeController vc = new VcodeController();
                                    return vc.show(url4vcode);
                            }
                        });
 
                        Platform.runLater(query);       // 重点 
                        String vcode = query.get();     // 这样就能获取返回值 
                        System.out.println(vcode);

/**
 * Runs the specified {@link Runnable} on the
 * JavaFX application thread and waits for completion.
 *
 * @param action the {@link Runnable} to run
 * @throws NullPointerException if {@code action} is {@code null}
 */
public static void runAndWait(Runnable action) {
    if (action == null)
        throw new NullPointerException("action");
 
    // run synchronously on JavaFX thread
    if (Platform.isFxApplicationThread()) {
        action.run();
        return;
    }
 
    // queue on JavaFX thread and wait for completion
    final CountDownLatch doneLatch = new CountDownLatch(1);
    Platform.runLater(() -> {
        try {
            action.run();
        } finally {
            doneLatch.countDown();
        }
    });
 
    try {
        doneLatch.await();
    } catch (InterruptedException e) {
        // ignore exception
    }
}

package com.yz.readismqtest1; 
import javafx.concurrent.Task; 
public class deda {
    public static void main(String[] args) {
        Task task = new Task() {
            @Override
            protected Object call() throws Exception {
                //执行普通方法
                return null;
            }
 
            @Override
            protected void scheduled() {
                //更新JavaFX的主线程的代码放在此处
                super.scheduled();
            } 
 
            @Override
            protected void succeeded() {
                //更新JavaFX的主线程的代码放在此处
                super.succeeded();
            }
 
            @Override
            protected void running() {
                //更新JavaFX的主线程的代码放在此处
                super.running();
            }
        }; 
    }
}

// 1、从线程池中获取对象
 ObjectPoolDrawUIService objPool = ObjectPoolDrawUIService.getInstance();
 DrawUIService obj = (DrawUIService)objPool.getObject();
 
 // 2、对象的初始化   produceCaseResult是需要更新的数据内容  ,i是行号信息，放在Object[]中进行传递
 obj.init(new Object[]{produceCaseResult,i}, new EventHandler<WorkerStateEvent>() {
  @Override
  public void handle(WorkerStateEvent t) {
   Object[] objArray = (Object[])t.getSource().getValue();
   testDetailList.set((int) objArray[1], (ProduceCaseResult)objArray[0]);
   // 4、因为是在线程中执行，所以 returnObject代码不能跟在obj.restart后面，会导致被很快的restart
   objPool.returnObject(obj);
  }
 });
 
 // 3、执行
 obj.restart();  // 因为是从pool中获取，可能已经执行完毕，所以restart
以上代码中需要特别注意，代码4的位置，以下代码为javafx.concurrent的核心代码
public class DrawUIService extends Service<Object[]>{
 Object[] showData = {null,null};
 public void init(Object[] showData, EventHandler<WorkerStateEvent> eventHandler) {
  this.showData = showData;
  setOnSucceeded(eventHandler);
 }
 @Override
 protected Task<Object[]> createTask() {
  return new Task<Object[]>() {
   @Override
   protected Object[] call() throws Exception {
    return showData;
   }
  };
 }
}