TCP协议

//服务端

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;

public class Server {
public static void main(String[] args) {
try {
ServerSocket server = new ServerSocket(5111);//创建服务器套接字
System.out.println("服务器创建成功，等待用户接入...");
Socket client = server.accept();//等待用户接入
System.out.println("有客户端接入，客户端IP："+client.getInetAddress());//获取客户端地址
OutputStream out = client.getOutputStream();
String message = "这里是服务器，你的IP地址是:"+client.getInetAddress();
out.write(message.getBytes());
InputStream in = client.getInputStream();
byte[] bt = new byte[1024];
int len = in.read(bt);
String data = new String(bt, 0, len);
System.out.println("客户端发来消息："+data);

server.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}

//客户端

import java.io.*;
import java.net.*;

public class Client {
public static void main(String[] args) {
try {
Socket client = new Socket("127.0.0.1",5111);//创建客户端套接字，制定服务器地址
System.out.println("连接成功");
InputStream in = client.getInputStream();
byte[] bt = new byte[1024];
int len = in.read(bt);
String data = new String(bt,0,len);
System.out.println("服务器发来消息："+data);
OutputStream out = client.getOutputStream();
String message = "服务器你好，我是客户端。";
out.write(message.getBytes());


client.close();
} catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}