buttonpress.java

< ProJavaProgrammingSecondEdition> 书中例程源码

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class ButtonPress extends JFrame {

  public static void main(String[] args) {
    ButtonPress bp = new ButtonPress();
    bp.setSize(400, 300);
    bp.setVisible(true);
  } 

  public ButtonPress() {
    JMenuBar jmb = new JMenuBar();
    JMenu menu = new JMenu("Execute");
    jmb.add(menu);
    JMenuItem jmi = new JMenuItem("Database Query");
    menu.add(jmi);
    jmi.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent event) {
        Thread t = new Thread(new Runnable() {
          public void run() {
            performDatabaseQuery();
          } 
        });
        t.start();
      } 
    });
    setJMenuBar(jmb);
  }

  protected void performDatabaseQuery() {

    // Simulate long-running database query
    try {
      Thread.sleep(5000);
    } catch (Exception e) {}
    ;
  } 

}