3、UDP聊天实现

3、UDP聊天实现

System.in返回的是InputStream指向命令行输入的字节流，它的read方法以字节流的方式来读取命令行的输入的数据。

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetSocketAddress;
import java.net.SocketAddress;

public class UdpSender {
    public static void main(String[] args) throws Exception {
        //使用DatagramSocket建立UDP socket
        DatagramSocket socket = new DatagramSocket(8888);

      while (true){
          //UDP数据报，报文，从控制台读取
          BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

          //调用readline方法，读取输入的行数据
          String data = reader.readLine();
          //转换为字节
          byte[] datas=data.getBytes();
          //建立UDP数据报
          DatagramPacket packet = new DatagramPacket(datas, 0, datas.length, new InetSocketAddress("localhost",6666));
          //发送数据
          socket.send(packet);
          //退出判断
          if (data.equals("bye")){
              break;
          }

      }

        //关闭socket
        socket.close();
    }

}

import java.net.DatagramPacket;
import java.net.DatagramSocket;

public class UdpReciver {
    public static void main(String[] args) throws Exception {
        //使用DatagramSocket 建立UDP socket
        DatagramSocket socket = new DatagramSocket(6666);

        while (true){
            System.out.println("111111111111");
            //准备接收报文包
            byte[] container=new byte[1024];
            //建立udp数据报
            DatagramPacket packet = new DatagramPacket(container,0,container.length);
            //接收UDP数据报
            socket.receive(packet);
            //接收包裹
            byte[] data = packet.getData();
            String receiveData = new String(data,0,data.length);
            //打印接收
            System.out.println(receiveData);

            //断开连接 bye
            if (receiveData.equals("bye")){
                break;
            }
            //使用socket接收，阻塞式接收包裹
            socket.receive(packet);
        }
        socket.close();
    }
}