Java网络编程基础篇之单向通信

在网络编程中如果只要求客户机向服务器发送消息，不要求服务器向客户机发送消息，称为单线通信。客户机套接字和服务器套接字链接成功后，可估计通过输出流发送数据，服务器则通过输入流接受数据，下面是简单的单向通信的例子。

实例1：本实例是一个TCP服务器端程序，在 getserver() 方法中建立服务器套接字，调用getClienMessage()方法获取客户端信息。代码如下：

									import java.io.BufferedReader;

									import java.io.IOException;

									import java.io.InputStreamReader;

									import java.net.ServerSocket;

									import java.net.Socket;

									public class MyTcp {

									    private BufferedReader reader;

									    private ServerSocket server;

									    private Socket socket;

									    void getserver() {

									        try {

									            server = new ServerSocket(8998);

									            System.out.println("服务器套接字已经创建成功");

									            while(true) {

									                System.out.println("等待客户机的连接");

									                socket = server.accept();

									                reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));

									                getClienMessage();

									            }

									        }catch(Exception e) {

									            e.printStackTrace();

									        }

									    }

									    private void getClienMessage() {

									        try {

									            while (true) {

									                System.out.println("客户机："+ reader.readLine());

									            }

									        }catch(Exception e) {

									            e.printStackTrace();

									        }

									        try {

									            if(reader !=null) {

									                reader.close();

									            }

									            if(socket !=null) {

									                socket.close();

									            }

									        }catch(IOException e) {

									            e.printStackTrace();

									        }

									    }

									    public static void main(String[] args) {

									        MyTcp tcp = new MyTcp();

									        tcp.getserver();

									    }

									}

运行结果：

服务器套接字已经创建成功
等待客户机的连接

下面我们再来看一下客户端程序。

实例2：客户端程序，实现将用户在文本框输入的信息发送到服务器端，并将文本框中输入的信息显示在客户端的文本域中。代码如下：

									import java.awt.BorderLayout;

									import java.awt.Container;

									import java.awt.event.ActionEvent;

									import java.awt.event.ActionListener;

									import java.io.PrintWriter;

									import java.net.Socket;

									import javax.swing.JFrame;

									import javax.swing.JScrollPane;

									import javax.swing.JTextArea;

									import javax.swing.JTextField;

									import javax.swing.border.BevelBorder;

									public class MyClien extends JFrame{

									    private PrintWriter writer;

									    Socket socket;

									    private JTextArea ta = new JTextArea();

									    private JTextField tf = new JTextField();

									    Container cc;

									    public MyClien(String title) {

									        super(title);

									        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

									        cc = this.getContentPane();

									        final JScrollPane scrollPane = new JScrollPane();

									        scrollPane.setBorder(new BevelBorder(BevelBorder.RAISED));

									        getContentPane().add(scrollPane, BorderLayout.CENTER);

									        scrollPane.setViewportView(ta);

									        cc.add(tf,"South");

									        tf.addActionListener(new ActionListener() {

									            public void actionPerformed(ActionEvent e) {

									                writer.println(tf.getText());

									                ta.append(tf.getText()+ '\n');

									                ta.setSelectionEnd(ta.getText().length());

									                tf.setText("");

									            }

									        });

									    }

									        private void connect() {

									            ta.append("尝试连接\n");

									            try {

									                socket = new Socket("127.0.0.1",8998);

									                writer = new PrintWriter(socket.getOutputStream(),true);

									                ta.append("完成连接\n");

									            }catch(Exception e) {

									                e.printStackTrace();

									            }

									        }

									        public static void main(String[] args) {

									            MyClien clien = new MyClien("向服务器传送数据");

									            clien.setSize(200,200);

									            clien.setVisible(true);

									            clien.connect();

									        }

									    }