import java.awt.BorderLayout; import java.awt.event.*; import java.beans.PropertyChangeEvent; import java.beans.PropertyChangeListener; import java.util.List; import java.util.concurrent.ExecutionException; import javax.swing.*; import javax.swing.SwingWorker; public class SwingWorkerSample {     public static void main(String[] args) {         // 外观定义         try {             UIManager                     .setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");         } catch (Exception ex) {         }         // 窗体         JFrame f = new JFrame("SwingWorker Sample");         f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);         // 表示区         final JTextArea taOutput = new JTextArea(15, 30);         JScrollPane sp = new JScrollPane(taOutput);         f.add(sp);         // 底部进度条         final JProgressBar progressBar = new JProgressBar();         f.add(BorderLayout.SOUTH, progressBar);         // 开始按钮         JButton b = new JButton("开始");         f.add(BorderLayout.NORTH, b);         // 结束按钮         JButton b2 = new JButton("结束");         f.add(BorderLayout.AFTER_LINE_ENDS, b2);         // SwingWorker类         final SwingWorker<Integer, int[]> sw = new SwingWorker<Integer, int[]>() {             /** 执行操作 */             @Override             protected Integer doInBackground() throws Exception {                 int sum = 0;                 if (!this.isCancelled()) {                     for (int i = 1; i <= 10; ++i) {                         sum += i;                         publish(new int[] { i, sum });// 调用表示中间结果                         setProgress(i * 10);// 进度条                         Thread.sleep(1000);                     }                 }                 return sum;             }             /** 表示中间结果 */             @Override             protected void process(List<int[]> chunks) {                 StringBuilder sb = new StringBuilder();                 for (int[] values : chunks) {                     sb.append(String.format("累加%d等于%d%n", values[0], values[1]));                 }                 taOutput.append(sb.toString());             }             /** 处理完成 */             @Override             protected void done() {                 if (this != null && !this.isDone()) {                     try {                         int result = get();                         taOutput.append("完了。 合计" + result + "n");                     } catch (InterruptedException ex) {                     } catch (ExecutionException ex) {                     }                 }             }         };         // 进度条表示         sw.addPropertyChangeListener(new PropertyChangeListener() {             @Override             public void propertyChange(PropertyChangeEvent evt) {                 if ("progress".equals(evt.getPropertyName())) {                     progressBar.setValue((Integer) evt.getNewValue());                 }             }         });         // 开始按钮事件         b.addActionListener(new ActionListener() {             @Override             public void actionPerformed(ActionEvent e) {                 sw.execute();// 异步调用SwingWorkder             }         });         // 结束按钮         b2.addActionListener(new ActionListener() {             @Override             public void actionPerformed(ActionEvent e) {                 if (sw != null && !sw.isDone()) {                     // Cancel                     sw.cancel(true);                 }                 JOptionPane.showMessageDialog(null, "结束！");             }         });         // 窗体表示         f.pack();         f.setVisible(true);     } }