通过 UDP 发送 DatagramPacket

Question

我正在尝试通过 UDP 发送一些数据。这是我的代码：

public class UDP {
public static void main(String args[]) throws IOException { 
    InetAddress inetAddress = InetAddress.getByName("239.255.42.99");
    int PORT = 2225;
    int BUFFER_SIZE = 10;
    DatagramSocket datagramSocket = new DatagramSocket(PORT, inetAddress);
    byte[] buf = new byte[BUFFER_SIZE];
    String message = "0123456789";
    buf = message.getBytes();
    DatagramPacket datagramPacket = new DatagramPacket(buf, buf.length);

    datagramPacket = new DatagramPacket(buf, buf.length);
    datagramPacket.setAddress(inetAddress);
    datagramPacket.setPort(PORT);

    datagramSocket.send(datagramPacket);
    datagramSocket.setSoTimeout(1010);
}
}

我有这个错误：

Exception in thread "main" java.io.IOException: Invalid argument
at java.net.PlainDatagramSocketImpl.send(Native Method)
at java.net.DatagramSocket.send(DatagramSocket.java:698)
at UDP.main(UDP.java:21)

有人知道我做错了什么吗？

Answer 1

这样试试：

public static void main(String args[]) throws IOException {
    InetAddress inetAddress = InetAddress.getByName("239.255.42.99");
    int PORT = 2225;
    int BUFFER_SIZE = 10;
    DatagramSocket datagramSocket = new DatagramSocket();
    byte[] buf = new byte[BUFFER_SIZE];
    String message = "0123456789";
    buf = message.getBytes();
    DatagramPacket datagramPacket = new DatagramPacket(buf, buf.length, inetAddress, PORT);

    datagramSocket.send(datagramPacket);
    datagramSocket.setSoTimeout(1010);
}

通过 UDP 发送 DatagramPacket

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