udptimeclientframe.java

Java实例入门

package udptimeclient;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.net.*;
import java.util.*;
import java.io.*;

/**
 * Title:        时钟服务测试程序
 * Description:  这是一个使用时钟服务的客户端程序
 * Copyright:    Copyright (c) 2001
 * Company:
 * @author
 * @version 1.0
 */

public class UdpTimeClientFrame extends JFrame {
  JPanel contentPane;
  BorderLayout borderLayout1 = new BorderLayout();
  JPanel jPanelCmd = new JPanel();
  JButton command = new JButton();
  JPanel jPanelShowTime = new JPanel();
  JLabel jLabelTime = new JLabel();
  BorderLayout borderLayout2 = new BorderLayout();
  JLabel jLabel1 = new JLabel();
  JTextField txtServAddr = new JTextField();
  JLabel jLabel2 = new JLabel();
  JTextField txtServPort = new JTextField();

  /**Construct the frame*/
  public UdpTimeClientFrame() {
    enableEvents(AWTEvent.WINDOW_EVENT_MASK);
    try {
      jbInit();
    }
    catch(Exception e) {
      e.printStackTrace();
    }
  }
  /**Component initialization*/
  private void jbInit() throws Exception  {
    //setIconImage(Toolkit.getDefaultToolkit().createImage(UdpTimeClientFrame.class.getResource("[Your Icon]")));
    contentPane = (JPanel) this.getContentPane();
    contentPane.setLayout(borderLayout1);
    this.setSize(new Dimension(459, 99));
    this.setTitle("时钟服务测试程序");
    command.setText("读取时间");
    command.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        command_actionPerformed(e);
      }
    });
    jLabelTime.setFont(new java.awt.Font("SansSerif", 1, 20));
    jLabelTime.setHorizontalAlignment(SwingConstants.CENTER);
    jLabelTime.setText("在此处显示时间值");
    jPanelShowTime.setLayout(borderLayout2);
    jLabel1.setText("服务器地址");
    txtServAddr.setColumns(10);
    jLabel2.setText("服务端口号");
    txtServPort.setText("13");
    txtServPort.setColumns(5);
    jPanelCmd.add(jLabel1, null);
    jPanelCmd.add(txtServAddr, null);
    jPanelCmd.add(jLabel2, null);
    jPanelCmd.add(txtServPort, null);
    contentPane.add(jPanelCmd, BorderLayout.NORTH);
    jPanelCmd.add(command, null);
    contentPane.add(jPanelShowTime, BorderLayout.CENTER);
    jPanelShowTime.add(jLabelTime, BorderLayout.CENTER);
  }
  /**Overridden so we can exit when window is closed*/
  protected void processWindowEvent(WindowEvent e) {
    super.processWindowEvent(e);
    if (e.getID() == WindowEvent.WINDOW_CLOSING) {
      System.exit(0);
    }
  }

  void command_actionPerformed(ActionEvent e) {
  byte[]         outBuffer = new byte[1];
  byte[]         inBuffer = new byte[512];
   try{
       String host = txtServAddr.getText().trim() ;
       InetAddress hostAddress = InetAddress.getByName(host);
       DatagramSocket timeSocket = new DatagramSocket();
       // 创建请求和应答缓冲区
       DatagramPacket request = new DatagramPacket(outBuffer, outBuffer.length, hostAddress, 13);
       DatagramPacket reply = new DatagramPacket(inBuffer, inBuffer.length);
       // 发送请求并读取应答
       try {
             timeSocket.setSoTimeout(5 * 1000);
             timeSocket.send(request);
             timeSocket.receive(reply);
             jLabelTime.setText(new String(inBuffer, 0, reply.getLength()));
        } finally {
                  timeSocket.close();
        }
   } catch(Exception ex) {
         System.out.println(ex);
   }
  }
}