• 1.发送Send
  • 创建DatagramSocket, 随机端口号
  • 创建DatagramPacket, 指定数据, 长度, 地址, 端口
  • 使用DatagramSocket发送DatagramPacket
  • 关闭DatagramSocket
• 2.接收Receive
  • 创建DatagramSocket, 指定端口号
  • 创建DatagramPacket, 指定数组, 长度
  • 使用DatagramSocket接收DatagramPacket
  • 关闭DatagramSocket
  • 从DatagramPacket中获取数据
• 3.接收方获取ip和端口号
  • String ip = packet.getAddress().getHostAddress();
  • int port = packet.getPort();

 

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UDP传输优化

• 接收端Receive

• DatagramSocket socket = new DatagramSocket(6666);                       //创建socket相当于创建码头DatagramPacket packet = new DatagramPacket(new byte[1024], 1024);       //创建packet相当于创建集装箱while(true) {    socket.receive(packet);                                             //接收货物     byte[] arr = packet.getData();    int len = packet.getLength();    String ip = packet.getAddress().getHostAddress();    System.out.println(ip + ":" + new String(arr,0,len));}

   

• 发送端Send

  DatagramSocket socket = new DatagramSocket();       //创建socket相当于创建码头Scanner sc = new Scanner(System.in);while(true) {    String str = sc.nextLine();    if("quit".equals(str))        break;    DatagramPacket packet =                             //创建packet相当于创建集装箱            new DatagramPacket(str.getBytes(), str.getBytes().length, InetAddress.getByName("127.0.0.1"), 6666);    socket.send(packet);            //发货}socket.close();

   

 

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UDP传输多线程

发送和接收在一个窗口完成

public class Demo_MoreThread {    /**     * @param args     */    public static void main(String[] args) {        new Receive().start();        new Send().start();    }}class Receive extends Thread {    public void run() {        try {            DatagramSocket socket = new DatagramSocket(6666);                   //创建socket相当于创建码头            DatagramPacket packet = new DatagramPacket(new byte[1024], 1024);   //创建packet相当于创建集装箱            while(true) {                socket.receive(packet);                                             //接收货物                byte[] arr = packet.getData();                int len = packet.getLength();                String ip = packet.getAddress().getHostAddress();                System.out.println(ip + ":" + new String(arr,0,len));            }        } catch (IOException e) {            e.printStackTrace();        }    }}class Send extends Thread {    public void run() {        try {            DatagramSocket socket = new DatagramSocket();       //创建socket相当于创建码头            Scanner sc = new Scanner(System.in);            while(true) {                String str = sc.nextLine();                if("quit".equals(str))                    break;                DatagramPacket packet =                             //创建packet相当于创建集装箱                        new DatagramPacket(str.getBytes(), str.getBytes().length, InetAddress.getByName("127.0.0.1"), 6666);                socket.send(packet);            //发货            }            socket.close();        }  catch (IOException e) {            e.printStackTrace();        }    }}