让 UDPServer 发送给 UDPClient

Question

我正在尝试向客户端发送数据，但我还没有弄明白这是我的代码。

UDP 客户端：

BufferedReader input = new BufferedReader(new InputStreamReader(System.in));

DatagramSocket datagramSocket = new DatagramSocket( );
InetAddress ipServer = InetAddress.getByName("localhost");

byte[] sendDatagram = new byte[1054];
byte[] sendDatagramB = new byte[1055];
byte[] sendDatagramC = new byte[1056];

byte[] receiveDatagram = new byte[1054];
byte[] receiveDatagramB = new byte[1055];
byte[] receiveDatagramC = new byte[1056];
while  (true) {
    System.out.println("Ingrese X");
    String msgA = input.readLine();
    System.out.println("Ingrese B");
    String msgB = input.readLine();
    System.out.println("Ingrese C");
    String msgC = input.readLine();


    sendDatagram = (msgA.getBytes());
    DatagramPacket sendPacket = new DatagramPacket(sendDatagram, sendDatagram.length, ipServer, 6667);
    datagramSocket.send(sendPacket);

    sendDatagramB = (msgB.getBytes());
    DatagramPacket sendPacketB = new DatagramPacket(sendDatagramB, sendDatagramB.length, ipServer, 6667);
    datagramSocket.send(sendPacketB);

    sendDatagramC = (msgC.getBytes());
    DatagramPacket sendPacketC = new DatagramPacket(sendDatagramC, sendDatagramC.length, ipServer, 6667);
    datagramSocket.send(sendPacketC);
}

UDP 服务器：

BufferedReader input = new BufferedReader(new InputStreamReader(System.in));

DatagramSocket datagramSockets = new DatagramSocket( );
InetAddress ipServer = InetAddress.getByName("localhost");

byte[] sendDatagrams = new byte[1054];
byte[] receiveDatagrams = new byte[1054];

DatagramSocket datagramSocket = new DatagramSocket(6667);
byte[] sendDatagram = new byte[1054];
byte[] receiveDatagram = new byte[1054];

byte[] sendDatagramB = new byte[1055];
byte[] receiveDatagramB = new byte[1055];

byte[] sendDatagramC = new byte[1056];
byte[] receiveDatagramC = new byte[1056];

System.out.println("Server Start");

while (true){

    DatagramPacket receivePacket = new DatagramPacket(receiveDatagram,receiveDatagram.length);
    datagramSocket.receive(receivePacket);
    String receive = new String(receivePacket.getData());
    System.out.println(receive+"x");

    InetAddress ipClient = receivePacket.getAddress();
    int portClient = receivePacket.getPort();
    receiveDatagram = new byte[1054];
    String msgClient = "Hola Mundo";

    DatagramPacket receivePacketB = new DatagramPacket(receiveDatagramB,receiveDatagramB.length);
    datagramSocket.receive(receivePacketB);
    String receiveB = new String(receivePacketB.getData());
    System.out.println(receiveB+"y");

    InetAddress ipClientB = receivePacketB.getAddress();
    int portClientB = receivePacketB.getPort();
    receiveDatagramB = new byte[1055];
    String msgClientB = "Hola Mundo";

    DatagramPacket receivePacketC = new DatagramPacket(receiveDatagramC,receiveDatagramB.length);
    datagramSocket.receive(receivePacketC);
    String receiveC = new String(receivePacketC.getData());
    System.out.println(receiveC+"z");

    InetAddress ipClientC = receivePacketC.getAddress();
    int portClientC = receivePacketC.getPort();
    receiveDatagramC = new byte[1056];
    String msgClientC = "Hola Mundo";



    Double x1 =  (-portClientB - (Math.sqrt((portClient*portClientB - ((4*portClient*portClientC))))))/ (2 * portClientC);
    Double x2 =  (-portClientB + (Math.sqrt((portClient*portClientB - ((4*portClient*portClientC))))))/ (2 * portClientC);

    String xa = String.valueOf(x1);
    String xb = String.valueOf(x2);
    System.out.println("El Resultado de x1 es = "+" "+x1);
    System.out.println("El Resultado de x1 es = "+" "+x2);
}

我想将字符串 XA 和 XB 发送给客户端。

Answer 1

我不知道你到底在用 udp 套接字做什么，但通常服务器必须支持所有请求，包括来自客户端的协议。

这是我的 udp 套接字服务器从您的源代码中看到的样子：

package justtest;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;

public class UDPServer {
    public static void main(String[] args) throws IOException {
        DatagramSocket datagramSocket = new DatagramSocket(6667);
        byte[] sendDatagram = new byte[1054];
        byte[] receiveDatagram = new byte[1054];

        System.out.println("Server Start");
        try
        {
            while (true) 
            {


                DatagramPacket receivePacket = new DatagramPacket(receiveDatagram, receiveDatagram.length);
                datagramSocket.receive(receivePacket);
                //System.out.println("len" + receivePacket.getLength());
                String receive = new String(receivePacket.getData());
                System.out.println(receive.trim() + " received...");

                //////// Do it what you want here //////////
                //////// done //////////////////////////////


                InetAddress IPAddress = receivePacket.getAddress();
                int port = receivePacket.getPort();

                String msgClient = "Hola Mundo";

                System.arraycopy(msgClient.getBytes(), 0, sendDatagram, 0, msgClient.getBytes().length);
                DatagramPacket sendPacket = new DatagramPacket(sendDatagram, sendDatagram.length, IPAddress, port);
                datagramSocket.send(sendPacket);

            }
        }
        finally
        {
            datagramSocket.close();
        }
    }
}

那么，udp客户端就可以做你该做的了。

package justtest;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;

public class UDPClient {
    public static void main(String[] args) throws IOException {
        BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
        InetAddress ipServer = InetAddress.getByName("localhost");
        DatagramSocket datagramSocket = null;
        DatagramSocket datagramSocketA = null;
        DatagramSocket datagramSocketB = null;
        byte[] sendDatagram = new byte[1054];
        byte[] sendDatagramB = new byte[1055];
        byte[] sendDatagramC = new byte[1056];

        byte[] receiveDatagram = new byte[1054];
        byte[] receiveDatagramB = new byte[1055];
        byte[] receiveDatagramC = new byte[1056];

        while (true) 
        {
            System.out.println();
            System.out.println("Ingrese X");
            String msgA = input.readLine();

            //sendDatagram = (msgA.getBytes());
            System.arraycopy(msgA.getBytes(), 0, sendDatagram, 0, msgA.getBytes().length);
            DatagramPacket sendPacket = new DatagramPacket(sendDatagram, sendDatagram.length, ipServer, 6667);
            DatagramPacket recvPacket = new DatagramPacket(sendDatagram, receiveDatagram.length, ipServer, 6667);

            datagramSocket = new DatagramSocket();
            datagramSocket.send(sendPacket);
            datagramSocket.receive(recvPacket);
            System.out.printf("Send...[%s]/ recv...[%s]", new String(sendDatagram).trim(), new String(recvPacket.getData()).trim());


            System.out.println();
            System.out.println("Ingrese B");
            String msgB = input.readLine();
            //sendDatagramB = (msgB.getBytes());
            System.arraycopy(msgB.getBytes(), 0, sendDatagramB, 0, msgB.getBytes().length);
            DatagramPacket sendPacketB = new DatagramPacket(sendDatagramB, sendDatagramB.length, ipServer, 6667);
            DatagramPacket recvPacketB = new DatagramPacket(receiveDatagramB, receiveDatagramB.length, ipServer, 6667);

            datagramSocketA = new DatagramSocket();
            datagramSocketA.send(sendPacketB);
            datagramSocketA.receive(recvPacketB);
            System.out.printf("Send...[%s]/ recv...[%s]", new String(sendDatagramB).trim(), new String(recvPacketB.getData()).trim());


            System.out.println();
            System.out.println("Ingrese C");

            String msgC = input.readLine();
            //sendDatagramC = (msgC.getBytes());
            System.arraycopy(msgC.getBytes(), 0, sendDatagramC, 0, msgC.getBytes().length);
            DatagramPacket sendPacketC = new DatagramPacket(sendDatagramC, sendDatagramC.length, ipServer, 6667);
            DatagramPacket recvPacketC = new DatagramPacket(receiveDatagramC, receiveDatagramC.length, ipServer, 6667);
            datagramSocketB = new DatagramSocket();
            datagramSocketB.send(sendPacketC);
            datagramSocketB.receive(recvPacketC);
            System.out.printf("Send...[%s]/ recv...[%s]", new String(sendDatagramC).trim(), new String(recvPacketC.getData()).trim());

            datagramSocket.close();
            datagramSocketA.close();
            datagramSocketB.close();
        }
    }
}

我认为重要的是您将使用代码做什么。

祝你好运。

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