网络编程--UDP通讯

UTP传输

public class Send1 {
    public static void main(String[] args) throws Exception {
        Scanner sc=new Scanner(System.in);
        DatagramSocket socket=new DatagramSocket();//码头
        while(true){
        String str=sc.nextLine();
        if("quit".equals(str)){
            break;
        }
        DatagramPacket packet=new DatagramPacket(str.getBytes(),str.length(), InetAddress.getByName("127.0.0.1"),6666);//集装箱
        socket.send(packet);
        }
        socket.close();
    }
}
class Receive{
    public static void main(String[] args) throws IOException {
        DatagramSocket socket=new DatagramSocket(6666);
        DatagramPacket packet=new DatagramPacket(new byte[1024],1024);//接受长度设置为1024
        while (true){
            socket.receive(packet);
            byte[] arr=packet.getData();
            int len=packet.getLength();                         //获取有效字节个数
            String ip=packet.getAddress().getHostAddress();     //获取IP地址
            int port = packet.getPort();                        //获得端口号
            System.out.println(new String(arr,0,len)+" "+"IP:"+ip+" "+"port:"+port);
        }

    }
}

使用多线程在同一窗口下完成

	public class Demo3_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();
			}
		}
	}