UDP 发送和接收

Posted 2023-02-17

【中文标题】UDP 发送和接收

【英文标题】：UDP Sending and Receiving

【发布时间】：2015-01-25 14:06:56

【问题描述】：

我已经研究了多种方法来做到这一点，但对于 Java UDP 数据包没有任何帮助/新的工作。

我的 android 代码通过服务启动并在新线程上运行。

等待代码：

        try 
            int port = 58452;

            // Create a socket to listen on the port.
            DatagramSocket dsocket = new DatagramSocket(port);

            // Create a buffer to read datagrams into. If a
            // packet is larger than this buffer, the
            // excess will simply be discarded!
            byte[] buffer = new byte[2048];

            // Create a packet to receive data into the buffer
            DatagramPacket packet = new DatagramPacket(buffer, buffer.length);

            // Now loop forever, waiting to receive packets and printing them.
            while (true) 
                // Wait to receive a datagram
                dsocket.receive(packet);

                // Convert the contents to a string, and display them
                String msg = new String(buffer, 0, packet.getLength());
                System.out.println(packet.getAddress().getHostName() + ": "
                        + msg);

                // Reset the length of the packet before reusing it.
                packet.setLength(buffer.length);
            
         catch (Exception e) 
            System.err.println(e);
        

发送代码：

 try 
      String host = "MY PHONES IP";
      int port = 58452; //Random Port

      byte[] message = "LAWL,LAWL,LAWL".getBytes();

      // Get the internet address of the specified host
      InetAddress address = InetAddress.getByName(host);

      // Initialize a datagram packet with data and address
      DatagramPacket packet = new DatagramPacket(message, message.length,
          address, port);

      // Create a datagram socket, send the packet through it, close it.
      DatagramSocket dsocket = new DatagramSocket();
      dsocket.send(packet);
      dsocket.close();
      System.out.println("Sent");
     catch (Exception e) 
      System.err.println(e);
    
  

它可以正常发送，但在 Android 上无法接收。请帮忙！

还有我的 Logcat 输出：http://pastebin.com/Rfw5mSKV

谢谢 -融合

【问题讨论】：

你试过在同一台机器上接收吗？确定它是正确的 ip 并且您的路由器没有过滤端口吗？乍一看，代码似乎没问题...

是的，我已经尝试了大约 10 个端口。我会在同一台机器上试试！

【参考方案1】：

http://systembash.com/content/a-simple-java-udp-server-and-udp-client/

我用过它并且它有效！感谢 /u/TarkLark 或 Reddit！