android UDP连接，不接收任何数据

android UDP connection, not receiving any data(android UDP连接，不接收任何数据)

问题描述

我是这方面的新手，所以如果我问愚蠢的问题，请联系我.

Im a newbie in this so please escuse me if i ask dumb questions.

我正在尝试在 Eclipse 的 PC Emulator 和一部安卓手机
(或两个安卓手机设备之间).

Im trying to make a UDP connection between Eclipse's PC Emulator & a android phone
(or between two android phone devices).

我有一个路由器，手机通过路由器的 wifi 网络连接到互联网.PC 也在同一网络上(直接电缆路由器-PC 连接).我试图将一些文本数据从服务器线程发送到客户端线程，但没有接收/发送任何内容.:(

I have a router and the phone connects to the internet thru router's wifi network. The PC is on same network also (direct cable router-PC connection). Im trying to send some text data from Server thread to Client thread but nothing is received/sent. :(

Server java 类(重新编辑，服务器从客户端接收消息):

public class server implements Runnable 
{
    // the Server's Port
    public static final int SERVERPORT  = 6000;

    // running Server thread.
    public void run() 
    {
        Log.d("redwing","server thread started.");
        DatagramSocket serverSocket = null;

        try
        {
            // Open Server Port
            serverSocket = new DatagramSocket(server.SERVERPORT);
            byte[] receiveData  = new byte[32];
            byte[] sendData     = new byte[32];
            // loop until "server_finished"  becomes False.
            while(createserver.server_finished)
            {
                if(renderer.gGL!=null)  // ignore me, just a null pointer checker
                {
                    // waiting for the incoming client's message packet
                    DatagramPacket receivePacket = new DatagramPacket(receiveData, receiveData.length);
                    serverSocket.receive(receivePacket);
                    renderer.recv = new String(receivePacket.getData());
                    Log.d("server","packet received from client, ETA " + timing.getNow() + " " + renderer.recv); // timing getNow - just returns current system minute & second.

                    // server is replying to the client back with a message.
                    InetAddress IPAddress = receivePacket.getAddress();
                    int port = receivePacket.getPort();

                    sendData = new String("server msg").getBytes();
                    DatagramPacket sendPacket = new DatagramPacket(sendData, sendData.length, IPAddress, port);
                    serverSocket.send(sendPacket);
                    renderer.sent = new String(sendData, 0, sendData.length);
                    Log.d("server","packet sent to client, ETA " + timing.getNow() + " " + renderer.sent);     // timing getNow - just returns current system minute & second.
                }
            }
            // close the socket
            if(serverSocket!=null) serverSocket.close();
            serverSocket = null;
        }
        catch (Exception e) 
        {
            Log.e("server", "Error", e);
            if(serverSocket!=null) serverSocket.close();
            serverSocket = null;
        }
        finally 
        {
            if(serverSocket!=null) serverSocket.close();
            serverSocket = null;
        }
        Log.d("redwing","server thread terminated.");
    }
}

和 Client java 类(重新编辑，客户端没有收到来自服务器的消息):

and the Client java class (RE-EDITED, Client does not receive msg from Server) :

public class client implements Runnable 
{
    public static final int CLIENTPORT  = 5000;
    // running Client thread.
    public void run() 
    {
        Log.d("redwing","client thread started.");
        DatagramSocket clientSocket = null;

        try
        {
            // getting local address 
            clientSocket = new DatagramSocket(server.SERVERPORT);
            InetAddress IPAddress = InetAddress.getByName("192.168.0.100");  

            // displaying IP & hostname.
            Log.d("client", "IP: " + IPAddress.getHostAddress() + " Name: " + IPAddress.getHostName());
            byte[] sendData     = new byte[32];
            byte[] receiveData  = new byte[32];
            // Loop until client_finished becomes False.
            while(createclient.client_finished)
            {
                if(renderer.gGL!=null)  // ignore me, just a null pointer checker
                {
                    // sending a message to the server
                    sendData = timing.getNow().getBytes();
                    DatagramPacket sendPacket = new DatagramPacket(sendData, sendData.length, IPAddress, client.CLIENTPORT);
                    clientSocket.send(sendPacket);
                    renderer.sent = new String(sendData,0,sendData.length);;
                    Log.d("client","packet sent to server, ETA " + timing.getNow());  

                    // waiting for the server packet message.
                    DatagramPacket receivePacket = new DatagramPacket(receiveData, receiveData.length);
                    clientSocket.receive(receivePacket);
                    renderer.recv = new String(receivePacket.getData());
                    Log.d("client","packet received from server, ETA " + timing.getNow());
                }
            }
            // close the socket
            if(clientSocket!=null) clientSocket.close();
            clientSocket = null;
        }
        catch (Exception e) 
        {
            Log.e("client", "Error", e);
            if(clientSocket!=null) clientSocket.close();
            clientSocket = null;
        }
        finally 
        {
            if(clientSocket!=null) clientSocket.close();
            clientSocket = null;
        } 
        Log.d("redwing","client thread terminated.");
    }
}

在清单中启用了权限:

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.INTERNET"/>
<user-permission android:name="android.permission.NETWORK" />
<uses-permission android:name="android.permission.CHANGE_WIFI_MULTICAST_STATE" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

我在安卓 PC 模拟器上运行服务器，在我的安卓手机上运行客户端.

I'm running the Server on the android PC Emulator, and the Client on my android Phone.

客户和服务器线程运行得很好但是......问题是我没有在它们之间交换任何数据.客户端没有收到任何东西，服务器也没有收到任何东西.数据包已发送，但没有收到任何内容.

Both Client & Server threads run just fine but ... the problem is that i dont get any data exchanged between them. The client doesn't receive anyting and the server doesnt receive anything. The packets are sent but nothing received .

我做错了什么?

请帮帮我.
提前谢谢你.

Please help me.
Thank you in advance.

推荐答案

运行模拟器后，在命令提示符下输入 - telnet localhost"，然后输入redir add udp:5000:6000".连接5000端口的客户端，打开6000端口的udp服务器，就可以收到来自udp服务器的客户端消息了.

After running your emulator, type it in command prompt - "telnet localhost ", then type "redir add udp:5000:6000". Connect client with port number 5000 and open udp server with port number 6000. Then you can receive client message from udp server.

查看详情

clientSocket = new DatagramSocket();
InetAddress IPAddress = InetAddress.getByName("<pc ip>"); // instead of "localhost"


public static final String SERVERIP = "127.0.0.1"; // 'Within' the emulator!  
public static final int SERVERPORT = 6000;   

/* Retrieve the ServerName */  
InetAddress serverAddr = InetAddress.getByName(SERVERIP);  
DatagramSocket socket = new DatagramSocket(SERVERPORT, serverAddr);  

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