client.java

Java程序设计实用教程源代码 本书源代码按章分别放置在不同的文件夹中,所有程序均在JDK1.6环境下编译运行正常,除了第13章需要建立ODBC数据源之外,其他程序只要有Java运行环境即可直接运行

import java.io.*;
import java.net.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Client extends JFrame {
  private JTextField jtf = new JTextField();
  private JTextArea jta = new JTextArea();
  private ObjectOutputStream outstream;
  private ObjectInputStream instream;
  private String message = "";
  private String serverinfo;
  private Socket client;
  public Client(String host) {
    super("客户端");
    serverinfo = host;
    Container container = getContentPane();
    jtf.setEnabled(false);
    jtf.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent event) {
        sendData(event.getActionCommand());
      }
    });
    container.add(jtf, BorderLayout.NORTH);
    container.add(new JScrollPane(jta), BorderLayout.CENTER);
    setSize(300, 150);
    setVisible(true);
  }
  public void runClient() { //客户端主程序
    try {
      connectToServer();
      getStreams();
      processConnection();
      closeConnection();
    }
    catch (EOFException eofException) {
      System.out.println("服务端已中止连接");
    }
    catch (IOException ioException) {
      ioException.printStackTrace();
    }
  }
  private void getStreams() throws IOException { //获取数据流
    outstream = new ObjectOutputStream(client.getOutputStream());//输出流
    outstream.flush();
    instream = new ObjectInputStream(client.getInputStream()); //获取输入流
    jta.append("\n获取I/O流\n");
  }
  private void connectToServer() throws IOException { //连接至服务器
    jta.setText("正在连接...\n");
    client = new Socket(InetAddress.getByName(serverinfo), 5000);
    jta.append("连接至: " + client.getInetAddress().getHostName());
  }
  private void processConnection() throws IOException { //连接过程处理
    // 将文本框jtf使能，客户端可通过其发送信息
    jtf.setEnabled(true);
    do {
      try {
        message = (String) instream.readObject();
        jta.append("\n" + message);
        jta.setCaretPosition(jta.getText().length());
      }
      catch (ClassNotFoundException classNotFoundException) {
        jta.append("\n接收到未知数据");
      }
    }
    while (!message.equals("服务端：中止连接"));
  }
  private void closeConnection() throws IOException { //关闭连接
    jta.append("\n正在关闭连接");
    outstream.close();
    instream.close();
    client.close();
  }
  private void sendData(String message) { //向服务端发送数据
    try {
      outstream.writeObject("客户端：" + message);
      outstream.flush();
      jta.append("\n客户端：" + message);
    }
    catch (IOException ioException) {
      jta.append("\n输入非法内容");
    }
  }
  public static void main(String args[]) {
    Client client;
    if (args.length == 0)
      client = new Client("127.0.0.1");
    else
      client = new Client(args[0]);
    client.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    client.runClient();
  }
}