Question

我已经创建了这个SpringBoot应用程序，通过用户数据报协议探索与Java的网络通信。我在Eclipse Java EE IDE for Web Developers中运行应用程序，版本：Oxygen.1a版本（4.7.1a）

这里是主要课程：

filter

这里创建了一个客户端UDP类来测试服务器

@Override
    public void run(String... args) throws Exception {

        socket = new DatagramSocket(UDP_PORT); 

        byte[] receiveData = new byte[BUFFER_SIZE];
        byte[] sendData    = new byte[BUFFER_SIZE];

        LOG.info("UDP server init...");

        while (true) {

            DatagramPacket receivePacket = new DatagramPacket(receiveData, receiveData.length);              
            socket.receive(receivePacket);  

            String sentence = new String( receivePacket.getData(), 0, receivePacket.getLength() );

            LOG.info("recived [" + sentence + "] from " + receivePacket.getAddress());

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

            DatagramPacket sendPacket = new DatagramPacket(receiveData, receiveData.length, IPAddress, receivePacket.getPort());
            socket.send (sendPacket);

        }       
    }

在我的电脑上工作正常，然后我在服务器上部署UDPServer，我使用ipconfig获取了ip

IPv4地址。。。。。。。。。。。：214.146.86.201

然后我更换＆＃34; localhost＆＃34;对于＆＃34; 214.146.86.201＆＃34;，但我没有收到服务器中的任何消息。

我已经从我的电脑中完成了public class UDPClient { private final static int TCP_PORT = 5202; private DatagramSocket socket; private InetAddress address; private byte[] buf; public UDPClient() throws SocketException, UnknownHostException { socket = new DatagramSocket(); address = InetAddress.getByName("localhost"); } public String sendEcho(String msg) throws IOException { buf = msg.getBytes(); DatagramPacket packet = new DatagramPacket(buf, buf.length, address, TCP_PORT); socket.send(packet); packet = new DatagramPacket(buf, buf.length); socket.receive(packet); String received = new String(packet.getData(), 0, packet.getLength()); return received; } public void close() { socket.close(); } public static void main(String[] args) throws IOException, InterruptedException { UDPClient udpClient = new UDPClient(); for (;;) { TimeUnit.SECONDS.sleep(3); System.out.println (udpClient.sendEcho("cullons")); } } }

结果：

nc -vzu 214.146.86.201 5202

但服务器在MacBook-Pro-de-lopes:$ nc -vzu 214.146.86.201 5202 found 0 associations found 1 connections: 1: flags=82<CONNECTED,PREFERRED> outif (null) src 192.166.26.140 port 56827 dst 214.146.86.201 port 5202 rank info not available Connection to 214.146.86.201 port 5202 [udp/*] succeeded!和LOG.info("socket InetAddres: " + socket.getInetAddress());上打印 null

我也尝试在服务器LOG.info("socket RemoteSocketAddress: " + socket.getRemoteSocketAddress());中使用相同的结果

Answer 1

最可能的问题可能是服务器上的5202端口无法从客户端访问。端口及其可访问性可能与TCP不同，但无论如何总是有可能中间有人丢弃您的数据包。

最简单的解决方法是尝试在服务器上运行客户端和服务器代码（214.146.86.201）。如果它可以连接意味着肯定存在通信问题（似乎）你可以使用Netcat检查here所述。我自己没试过。

Java UDP服务器无法正常工作

1 个答案: