☰

Java 多播套接字在 Windows 上未收到任何内容

tag-icon • tag-icon windows java multicast
Java 多播套接字在 Windows 上未收到任何内容

我需要以多播方式发送和接收。

我在 StackOverflow 论坛上发布了一个问题来检查我的代码：https://stackoverflow.com/questions/50131973/java-multicast-socket-doesnt-receive-anything-on-windows

我在 Ubuntu 上尝试了我的代码并且运行完美。

现在我在 Windows 10 上做实验。我使用多播套接字发送和接收 DatagramPacket。如果数据报的 InetAddress 为“230.0.0.1”进行多播，则不起作用。否则，当我使用 LAN 连接的机器的 IP 时，它可以工作。

接收者：

    MulticastSocket multiSocket = new MulticastSocket(3575);
    InetAddress groupMulticast = InetAddress.getByName( "230.0.0.1" );
    multiSocket.joinGroup(groupMulticast);
    DatagramPacket packetReceive = new DatagramPacket( bufReceive, bufReceive.length );
    try { 
        multiSocket.receive( packetReceive );
    } catch (IOException e) { e.printStackTrace(); }

发件人：

    MulticastSocket multiSocket = new MulticastSocket(3575);
    InetAddress groupMulticast = InetAddress.getByName( "230.0.0.1" );
    multiSocket.joinGroup(groupMulticast);
    byte[] bufSend = new byte[255];

    DatagramPacket packetSend = new DatagramPacket( bufSend, bufSend.length, 
                                    groupMulticast, 3575 );
    try {
        multiSocket.send(packetSend);
    } catch (IOException e) { e.printStackTrace(); }

此发送器不起作用。但如果我更改此设置：

InetAddress groupMulticast = InetAddress.getByName( "230.0.0.1" );

有了这个：

InetAddress groupMulticast = InetAddress.getByName( "192.168.0.21" );

其中 192.168.0.21 是接收器连接在 LAN 上的 IP 地址，它可以工作。

我如何进行多播发送？

答案1

尝试一下这个代码。

public class Server3 {

public static void main(String[] args) throws IOException {
    MulticastSocket multiSocket = new MulticastSocket(3575);
    InetAddress groupMulticast = InetAddress.getByName("224.0.0.1");
    multiSocket.setBroadcast(true);
    multiSocket.joinGroup(groupMulticast);

    while (true) {
        try {
            Thread.sleep(2000);
        } catch (InterruptedException e1) {
            e1.printStackTrace();
        }
        System.out.println("Sending...");
        String msg = "Hai";
        byte[] bufSend = msg.getBytes();

        DatagramPacket packetSend = new DatagramPacket(bufSend, bufSend.length, groupMulticast, 3575);
        try {
            multiSocket.send(packetSend);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}
}
public class Client3 {
public static void main(String[] args) throws IOException {
    MulticastSocket multiSocket = new MulticastSocket(3575);
    InetAddress groupMulticast = InetAddress.getByName("224.0.0.1");
    multiSocket.setBroadcast(true);
    multiSocket.joinGroup(groupMulticast);
    byte[] bufReceive = new byte[1024];
    while (true) {
        try {
            Thread.sleep(2000);
        } catch (InterruptedException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }
        System.out.println("Receiving...");
        DatagramPacket packetReceive = new DatagramPacket(bufReceive, bufReceive.length);
        try {
            multiSocket.receive(packetReceive);
            System.out.println("msg...");
            System.out.println(new String(bufReceive));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}
}

相关内容