[网络协议]JAVA 网络编程

TCP

三次握手四次挥手(三次干架,四次分手)
三次握手(三次干架)
A:你瞅啥
B:瞅你咋地
A:干他
四次挥手(四次分手)
A:我要走了
B:你真的要走了吗?
B:你真的真的要走了吗?
A:我真的要走了

package TCP;

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;

//服务器
public class TCPServer {
    public static void main(String[] args) throws IOException {
        ServerSocket ss = new ServerSocket(6000);
        Socket s = ss.accept();
        BufferedReader br = new BufferedReader(new InputStreamReader(s.getInputStream()));
        String str = null;
        while ((str = br.readLine()) != null){
            System.out.println("服务器接收数据为:" + str);
        }
        //接收状态转为发送状态
        s.shutdownInput();
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
        bw.write("我是小兰");
        //发送之后必须清空缓存区
        bw.flush();
        //关闭资源
        br.close();
        bw.close();
        s.close();
    }
}

package TCP;

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

//客户端
public class TCPClient{
    public static void main(String[] args) throws IOException {
        Socket s = new Socket("127.0.0.1" ,6000);
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
        bw.write("我是小明");
        //发送之后必须清空缓存区
        bw.flush();
        //发送状态转为接收状态
        s.shutdownOutput();
        BufferedReader br = new BufferedReader(new InputStreamReader(s.getInputStream()));
        String str = null;
        while ((str = br.readLine()) != null){
            System.out.println("客户端接收数据为:" + str);
        }
        //关闭资源
        bw.close();
        br.close();
        s.close();
    }
}

UDP

package UDP;

import java.io.IOException;
import java.net.*;
//服务端
public class UdpClient {
    public static void main(String[] args) throws IOException {
        DatagramSocket socket = new DatagramSocket(9000);
        byte[] buffer = new byte[1024];
        DatagramPacket packetReceive = new DatagramPacket(buffer , 0 , buffer.length);
        socket.receive(packetReceive);
        System.out.println("服务端接收到的数据:" + new String(buffer , 0 , packetReceive.getLength()));
        //接收数据
        String str = "你好 生活";
        InetAddress address = InetAddress.getByName("localhost");
        int port = packetReceive.getPort();;
        DatagramPacket packetSend = new DatagramPacket(str.getBytes() , 0 ,str.getBytes().length , address , port);
        socket.send(packetSend);
        //关闭UDP
        socket.close();
    }
}

package UDP;

import java.io.IOException;
import java.net.*;
//客户端
public class UdpClient2 {
    public static void main(String[] args) throws IOException {
        DatagramSocket socket = new DatagramSocket(9001);
        String str = "你好 世界";
        InetAddress address = InetAddress.getByName("localhost");
        int port = 9000;
        DatagramPacket packetSend = new DatagramPacket(str.getBytes() , 0 ,str.getBytes().length , address , port);
        socket.send(packetSend);
        //发送数据
        byte[] buffer = new byte[1024];
        DatagramPacket packetReceive = new DatagramPacket(buffer , 0 , buffer.length);
        socket.receive(packetReceive);
        System.out.println("客户端接收到的数据:" + new String(buffer , 0 , packetReceive.getLength()));
        //关闭UDP
        socket.close();
    }
}