Question

我正确地在服务器和客户端之间建立连接，并且我从客户端向服务器发送消息，但是我如何从服务器向客户端发送消息。我的意思是如何使服务器像客户端一样行动。我试图复制客户端方法到服务器可以调用的另一个类。但我不能然后我尝试创建一个新的包来使用服务器类中的客户端代码。任何建议？

ps：抱歉我的英文。

public class Entrance_Server extends JFrame{

JButton buton = new JButton("Create");
JButton buton2 = new JButton("Join");
JPanel butonpanel = new JPanel();
DatagramSocket sockServer = null;
DatagramSocket sockClient = null;
int port = 7777;
String s;
BufferedReader cin = new BufferedReader(new InputStreamReader(System.in));



public Entrance_Server() {

    setLayout(new GridLayout(2,1));

    add(buton);
    add(buton2);

    buton.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent e) {

            Choosing c = new Choosing();
            c.start();

            System.out.println("Server socket created. Waiting for incoming data...");



        }
    });

    buton2.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent e) {
            Choosing c = new Choosing();
            c.start();



        }
    });

}


public static void main(String[] args){

    Entrance_Server e = new Entrance_Server();
    e.setSize(500,350);
    e.setTitle("Welcome");
    e.setLocationRelativeTo(null);
    e.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    e.setVisible(true);

    e.connect();

}

public void connect (){

        try{
                sockServer = new DatagramSocket(7777);
                byte[] buffer = new byte[65536];
                DatagramPacket incoming = new DatagramPacket(buffer, buffer.length);

                while(true)
        {
            sockServer.receive(incoming);
            byte[] data = incoming.getData();
            String s = new String(data, 0, incoming.getLength());

            //echo the details of incoming data - client ip : client port - client message
            System.out.println(incoming.getAddress().getHostAddress() + " : " + incoming.getPort() + " - " + s);

            s = "OK : " + s;
            DatagramPacket dp = new DatagramPacket(s.getBytes() , s.getBytes().length , incoming.getAddress() , incoming.getPort());
            sockServer.send(dp);

            Entrance_Client_in_Server ec = new Entrance_Client_in_Server();
            ec.connectc();


        }
            }catch(IOException i){
                System.err.println("IOException " + i);
            }



}



}

Answer 1

在您的客户端上，您需要使用socket.Receive()

等待服务器响应

您可以像他们一样向服务器发送数据包后识别客户端。然后，您可以像这样识别客户端： InetAddress address = packet.getAddress(); int port = packet.getPort();

并使用它将数据包发送回客户端，客户端将使用socket.Receive（）读取响应;

有关使用UDP DatagramSockets检查的客户端/服务器连接的详细信息 Client-Server Datagram sockets

java-udp编程 - 从服务器到客户端的消息

1 个答案: