Java TCP网络通信

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Java TCP网络通信

InetAddress类

package page1;

import java.net.InetAddress;
import java.net.UnknownHostException;

public class MyTcp {
    public static void main(String[] args) {
        InetAddress ip;
        try {
            ip=InetAddress.getLocalHost();
            System.out.println("主机名：" + ip.getHostName());
            System.out.println("IP：" + ip.getHostAddress());
            
        } catch (UnknownHostException e) {
            
            e.printStackTrace();
        }
        
    }
}

image.png

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TCP网络程序

服务器端

package page2;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.ServerSocket;
import java.net.Socket;

public class TCP_Server {

    private BufferedReader reader;//从字符输入流中读取文本
    private ServerSocket server;//服务器套接字
    private Socket socket;//客户端套接字
    
    void getServer() throws Exception {
    
        server=new ServerSocket(1865);//创建套接字绑定到1865端口
        System.out.println("服务器套接字创建成功");
        while(true)
        {
            System.out.println("等待计算机的连接");
            socket=server.accept();//等待客户端连接，若连接，创建一个套接字
            reader=new BufferedReader(new InputStreamReader(socket
                    .getInputStream()));
            getClientMassage();
        }   
    }
    
    private void getClientMassage() throws Exception {
        
        while(true) 
        {
            System.out.println("Tsthzang:" + reader.readLine());
        }       
    }
    
    public static void main(String[] args) throws Exception {
        
        TCP_Server tcp_server=new TCP_Server();
        tcp_server.getServer();
    }       
}

客户端

package page2;

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.IOException;
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 TCP_Client extends JFrame{
    
    private PrintWriter writer;
    Socket socket;
    private JTextArea ta=new JTextArea();
    private JTextField tf=new JTextField();
    Container cc;
    
    public TCP_Client(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() {
            
            @Override
            public void actionPerformed(ActionEvent arg0) {
                
                writer.println(tf.getText());
                ta.append(tf.getText()+'\n');
                ta.setSelectionEnd(ta.getText().length());
                tf.setText("");     
            }
        }); 
    }
    
    private void connect() throws Exception {
        
        ta.append("尝试连接\n");
        
        socket=new Socket("127.0.0.1", 1865);
        writer=new PrintWriter(socket.getOutputStream(),true);
        ta.append("连接完成\n");
    }
    
    public static void main(String[] args) throws Exception {
        
        TCP_Client client=new TCP_Client("聊天程序客户端");
        client.setSize(200,200);
        client.setVisible(true);
        client.connect();
    }
    
}

image.png

PS . 完整服务器端程序：

package page2;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.ServerSocket;
import java.net.Socket;

public class TCP_Server {

    private BufferedReader reader;//从字符输入流中读取文本
    private ServerSocket server;//服务器套接字
    private Socket socket;//客户端套接字
    
    void getServer() {
        
        try {
            server=new ServerSocket(1865);
            System.out.println("服务器套接字创建成功");
            while(true)
            {
                System.out.println("等待计算机的连接");
                socket=server.accept();
                reader=new BufferedReader(new InputStreamReader(socket
                        .getInputStream()));
                getClientMassage();
            }
        } 
            catch (IOException e)
            {
                e.printStackTrace();
            }
    }
    
    private void getClientMassage() {
        
        try{
            while(true) 
            {
                System.out.println("Tsthzang:" + reader.readLine());
            }       
        } 
            catch (IOException 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) {
        
        TCP_Server tcp_server=new TCP_Server();
        tcp_server.getServer();
    }
            
}

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总结：

ServerSocket类

ServerSocket的构造方法都抛出IOException

accept();//等待客户端连接，若连接，创建一个套接字(返回值：Socket)
bind(SocketAddress endpoint);//绑定到特定地址（IP地址和端口号）

isBound();//判断ServerSocket的绑定状态

getInetAddress();//返回此服务器套接字的本地地址(返回值：InetAddress)
getInetAddress();//返回此服务器套接字等待的端口号(返回值：int)

isClosed();//判断关闭状态
close();//关闭

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参考资料：

• Java从入门到精通