我打算在所有工人完成任务后一起删除所有标签。
如上所述这里，一个CountDownLatch在这方面效果很好。在下面的示例中，每个工作程序latch.countDown()在完成时调用，而Supervisor工作程序则在latch.await()所有任务完成之前阻塞。出于演示目的，Supervisor更新标签。注释中显示的批量移除在技术上是可行的，但通常没有吸引力。而是考虑一个JList或JTable。
import java.awt.Color;import java.awt.EventQueue;import java.awt.GridLayout;import java.awt.event.ActionEvent;import java.util.linkedList;import java.util.List;import java.util.Queue;import java.util.Random;import java.util.concurrent.CountDownLatch;import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;import javax.swing.*;public class WorkerLatchTest extends JApplet { private static final int N = 8; private static final Random rand = new Random(); private Queue<JLabel> labels = new linkedList<JLabel>(); private JPanel panel = new JPanel(new GridLayout(0, 1)); private JButton startButton = new JButton(new StartAction("Do work")); public static void main(String[] args) { EventQueue.invokeLater(new Runnable() { @Override public void run() { Jframe frame = new Jframe(); frame.setTitle("Test"); frame.setDefaultCloseOperation(Jframe.EXIT_ON_CLOSE); frame.add(new WorkerLatchTest().createGUI()); frame.pack(); frame.setLocationRelativeTo(null); frame.setVisible(true); } }); } @Override public void init() { EventQueue.invokeLater(new Runnable() { @Override public void run() { add(new WorkerLatchTest().createGUI()); } }); } private JPanel createGUI() { for (int i = 0; i < N; i++) { JLabel label = new JLabel("0", JLabel.CENTER); label.setOpaque(true); panel.add(label); labels.add(label); } panel.add(startButton); return panel; } private class StartAction extends AbstractAction { private StartAction(String name) { super(name); } @Override public void actionPerformed(ActionEvent e) { startButton.setEnabled(false); CountDownLatch latch = new CountDownLatch(N); ExecutorService executor = Executors.newFixedThreadPool(N); for (JLabel label : labels) { label.setBackground(Color.white); executor.execute(new Counter(label, latch)); } new Supervisor(latch).execute(); } } private class Supervisor extends SwingWorker<Void, Void> { CountDownLatch latch; public Supervisor(CountDownLatch latch) { this.latch = latch; } @Override protected Void doInBackground() throws Exception { latch.await(); return null; } @Override protected void done() { for (JLabel label : labels) { label.setText("Fin!"); label.setBackground(Color.lightGray); } startButton.setEnabled(true); //panel.removeAll(); panel.revalidate(); panel.repaint(); } } private static class Counter extends SwingWorker<Void, Integer> { private JLabel label; CountDownLatch latch; public Counter(JLabel label, CountDownLatch latch) { this.label = label; this.latch = latch; } @Override protected Void doInBackground() throws Exception { int latency = rand.nextInt(42) + 10; for (int i = 1; i <= 100; i++) { publish(i); Thread.sleep(latency); } return null; } @Override protected void process(List<Integer> values) { label.setText(values.get(values.size() - 1).toString()); } @Override protected void done() { label.setBackground(Color.green); latch.countDown(); } }}
