image.png

image.png

適用于一次的少量的連接

服務器

package com.company;

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

public class UDPServer {
    public static void main(String[] args) {
        try {
            //1、創(chuàng)建服務器端DatagramSocket
            DatagramSocket datagramSocket = new DatagramSocket(8080);

            while (true){
                //2君丁、創(chuàng)建數(shù)據(jù)報啼辣，用于接收客戶端發(fā)送的數(shù)據(jù)
                byte[] bytes=new byte[1024];//1k
                DatagramPacket datagramPacket = new DatagramPacket(bytes, bytes.length);
                System.out.println("服務器端等待新的客戶端發(fā)送數(shù)據(jù)");
                //3朴乖、此方法在獲取到數(shù)據(jù)報之前原环，會處于阻塞狀態(tài)
                datagramSocket.receive(datagramPacket);

                new UDPServerThread(datagramSocket,datagramPacket,bytes).run();
            }


//            datagramSocket.close();
        } catch (SocketException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

多線程

package com.company;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;

public class UDPServerThread extends Thread {

    DatagramPacket datagramPacket;
    byte[] bytes;

    //和本線程相關的DatagramSocket
    DatagramSocket datagramSocket = null;


    public UDPServerThread(DatagramSocket datagramSocket,DatagramPacket datagramPacket,
                           byte[] bytes) {
        this.datagramSocket = datagramSocket;
        this.datagramPacket = datagramPacket;
        this.bytes = bytes;
    }

    @Override
    public void run() {

        try {
            //4、讀取數(shù)據(jù)
            String info = new String(bytes, 0, datagramPacket.getLength(), "gbk");
            System.out.println("獲取到客戶端數(shù)據(jù)：" + info);

            //5芽世、響應客戶端數(shù)據(jù)，創(chuàng)建數(shù)據(jù)包
            InetAddress address = datagramPacket.getAddress();//客戶端地址
            int port = datagramPacket.getPort();//客戶端端口
            byte[] bytes1 = "歡迎您".getBytes("gbk");
            DatagramPacket packet = new DatagramPacket(bytes1, bytes1.length, address, port);
            datagramSocket.send(packet);
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

客戶端

package com.company;

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

public class UDPClient {

    public static void main(String[] args) {
        try {
            //1聋呢、定義服務器的地址、端口號颠区、數(shù)據(jù)
            InetAddress inetAddress = InetAddress.getByName("localhost");
            int port = 8080;
            //2削锰、創(chuàng)建DatagramSocket對象
            DatagramSocket socket = new DatagramSocket();

            //3、創(chuàng)建數(shù)據(jù)報
            byte[] bytes = "admin;456".getBytes("gbk");
            DatagramPacket packet = new DatagramPacket(bytes, bytes.length, inetAddress, port);

            //4毕莱、發(fā)送數(shù)據(jù)報
            socket.send(packet);

            //5器贩、闖將獲取的數(shù)據(jù)報
            byte[] bytes1 = new byte[1024];
            DatagramPacket packet1 = new DatagramPacket(bytes1, bytes1.length);
            socket.receive(packet1);

            String info = new String(bytes1, 0, packet1.getLength(), "gbk");
            System.out.print("收到服務端數(shù)據(jù)：" + info);


            //5、關閉資源
            socket.close();

        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (SocketException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}