UDP聊天室-消息发送接收

发送端

//udp不需要连接服务器
public class send {
    public static void main(String[] args) {
        //建立一个socket
        DatagramSocket socket = null;
        try {
            socket = new DatagramSocket();
            //建立包，从控制台读取System.in
            BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
            while (true) {
                String data = reader.readLine();
                //发送
                DatagramPacket packet = new DatagramPacket(data.getBytes(), 0, data.getBytes().length, InetAddress.getByName("localhost"), 6666);
                socket.send(packet);
                //判断是否断开
                if (data.equals("over")) {
                    break;
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (socket != null) {
                try {
                    socket.close();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

接收端

//udp不需要连接服务器
public class receive {
    public static void main(String[] args) {
        //建立一个socket
        DatagramSocket socket = null;
        try {
            //接收包
            socket = new DatagramSocket(6666);
            while (true) {
                //创建Buffer
                byte[] buffer = new byte[1024];
                DatagramPacket packet = new DatagramPacket(buffer, 0, buffer.length);
                //阻塞接收
                socket.receive(packet);
                //接收数据
                String data = new String(packet.getData(), 0, packet.getLength());
                //判断是否断开
                if (data.equals("over")) {
                    break;
                }
                System.out.println(data);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (socket != null) {
                try {
                    socket.close();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

发送端可无限发送消息给接收端，直到发送over，结束