java - 如何在局域网(LAN)外部连接DatagramSocket服务器和客户端？

我可以将我的DatagramSocket服务器和客户端连接到局域网（LAN）内，但不能在它之外。

这是我的代码：

GameServer类：

public class GameServer extends Thread {

private DatagramSocket socket;

public GameServer() {
    try {
        this.socket = new DatagramSocket(7081,InetAddress.getByName("0.0.0.0"));
    } catch (Exception e) {
        e.printStackTrace();
    }
}

public void run() {
    while (true) {
        byte[] data = new byte[1024];
        DatagramPacket packet = new DatagramPacket(data, data.length);
        try {
            socket.receive(packet);
            if(new String(packet.getData()).trim().equalsIgnoreCase("ping")){
                sendData("pong".getBytes(),packet.getAddress(),packet.getPort());
            }
            System.out.println(new String(packet.getData()));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}


public void sendData(byte[] data, InetAddress ipAddress, int port) {

        DatagramPacket packet = new DatagramPacket(data, data.length, ipAddress, port);
        try {
            this.socket.send(packet);
        } catch (IOException e) {
            e.printStackTrace();
        }
}

}

GameClient类：

public class GameClient extends Thread {

private InetAddress ipAddress;
private DatagramSocket socket;

public GameClient(String ipAddress) {
    try {
        this.socket = new DatagramSocket();
        this.ipAddress = InetAddress.getByName(ipAddress);
    } catch (SocketException e) {
        e.printStackTrace();
    } catch (UnknownHostException e) {
        e.printStackTrace();
    }
}

public void run() {
    while (true) {
        byte[] data = new byte[1024];
        DatagramPacket packet = new DatagramPacket(data, data.length);
        try {
            socket.receive(packet);
            System.out.println(new String(packet.getData()));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}


public void sendData(byte[] data) {

        DatagramPacket packet = new DatagramPacket(data, data.length, ipAddress, 7081);
        try {
            socket.send(packet);
        } catch (IOException e) {
            e.printStackTrace();
    }
}

}

RunClient类：

public class RunClient {
public static void main(String[] args) {
    GameClient client = new GameClient("/*Here is my external ip address*/"); //If i am running this for LAN then 192.168.1.67 and localhost work
    client.start();
    client.sendData("ping".getBytes());
}
}

RunServer类：

public class RunServer {
public static void main(String[] args) {
    GameServer server = new GameServer();
    server.start();
}
}

这是我的端口转发配置：



一些其他信息：
我的本地IP地址是192.168.1.67
我正在使用的端口是7081
当我检查http://www.canyouseeme.org处的IP和端口时，出现以下错误：

Error: I could not see your service on "my external ip" on port (7081)

最佳答案

我看不到您的代码中的任何问题。该站点（http://www.canyouseeme.org）必须尝试使用​​TCP而不是UDP。