java_concurrency_in_practice_source源代码

package net.jcip.examples; import java.awt.*; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.util.*; import java.util.concurrent.*; import javax.swing.*; /** * ListenerExamples * * @author Brian Goetz and Tim Peierls */ public class ListenerExamples { private static ExecutorService exec = Executors.newCachedThreadPool(); private final JButton colorButton = new JButton("Change color"); private final Random random = new Random(); private void backgroundRandom() { colorButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { colorButton.setBackground(new Color(random.nextInt())); } }); } private final JButton computeButton = new JButton("Big computation"); private void longRunningTask() { computeButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { exec.execute(new Runnable() { public void run() { /* Do big computation */ } }); } }); } private final JButton button = new JButton("Do"); private final JLabel label = new JLabel("idle"); private void longRunningTaskWithFeedback() { button.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { button.setEnabled(false); label.setText("busy"); exec.execute(new Runnable() { public void run() { try { /* Do big computation */ } finally { GuiExecutor.instance().execute(new Runnable() { public void run() { button.setEnabled(true); label.setText("idle"); } }); } } }); } }); } private final JButton startButton = new JButton("Start"); private final JButton cancelButton = new JButton("Cancel"); private Future<?> runningTask = null; // thread-confined private void taskWithCancellation() { startButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { if (runningTask != null) { runningTask = exec.submit(new Runnable() { public void run() { while (moreWork()) { if (Thread.currentThread().isInterrupted()) { cleanUpPartialWork(); break; } doSomeWork(); } } private boolean moreWork() { return false; } private void cleanUpPartialWork() { } private void doSomeWork() { } }); } ; } }); cancelButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent event) { if (runningTask != null) runningTask.cancel(true); } }); } private void runInBackground(final Runnable task) { startButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { class CancelListener implements ActionListener { BackgroundTask<?> task; public void actionPerformed(ActionEvent event) { if (task != null) task.cancel(true); } } final CancelListener listener = new CancelListener(); listener.task = new BackgroundTask<Void>() { public Void compute() { while (moreWork() && !isCancelled()) doSomeWork(); return null; } private boolean moreWork() { return false; } private void doSomeWork() { } public void onCompletion(boolean cancelled, String s, Throwable exception) { cancelButton.removeActionListener(listener); label.setText("done"); } }; cancelButton.addActionListener(listener); exec.execute(task); } }); } }