android UDP连接，没有接收任何数据 [英] android UDP connection, not receiving any data

问题描述

我试图在Eclipse的PC仿真器和PC之间建立一个UDP连接。一个android手机

（或两个Android手机设备之间）。

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在同一网络上（直接电缆路由器-PC连接）。我试图从服务器线程发送一些文本数据到客户端线程，但没有收到/发送。 ：

服务器 java类（重新编辑，服务器从客户端接收msg。 p>

  public class server implements Runnable 
 {
 //服务器端口
 public static final int SERVERPORT = 6000; 
 
 //运行服务器线程
 public void run（）
 {
 Log.d（redwing，服务器线程已启动。 ; 
 DatagramSocket serverSocket = null; 
 
 try 
 {
 //打开服务器端口
 serverSocket = new DatagramSocket（server.SERVERPORT）; 
 [b] [b] [b] [b] [b] [b] [b] [b] ）
 {
 if（renderer.gGL！= null）//忽略我，只是一个空指针检查器
 {
 //等待传入客户端的消息包
 DatagramPacket receivePacket = new DatagramPacket（receiveData，receiveData.length）; 
 serverSocket.receive（receivePacket）; 
 renderer.recv = new String（receivePacket.getData（））; 
 Log.d（server，从客户端收到的数据包，ETA+ timing.getNow（）++ renderer.recv）; // timing getNow  -  just returns current system minute&第二。 
 
 //服务器正在向客户端回复一条消息。 
 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&第二。 
} 
} 
 //关闭套接字
 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。）; 
} 
} 
  

和客户端 java类（重新编辑，客户端不从服务器接收msg ）：

  Runnable 
 {
 public static final int CLIENTPORT = 5000; 
 //运行客户线程。 
 public void run（）
 {
 Log.d（redwing，client thread started。 
 DatagramSocket clientSocket = null; 
 
 try 
 {
 //获取本地地址
 clientSocket = new DatagramSocket（server.SERVERPORT）; 
 InetAddress IPAddress = InetAddress.getByName（192.168.0.100）; 
 
 //显示IP&主机名。 
 Log.d（client，IP：+ IPAddress.getHostAddress（）+Name：+ IPAddress.getHostName（））; 
 byte [] sendData = new byte [32]; 
 byte [] receiveData = new byte [32]; 
 //循环，直到client_finished变为False。 
 while（createclient.client_finished）
 {
 if（renderer.gGL！= null）//忽略我，只是一个空指针检查器
 {
 //发送一个消息到服务器
 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（））; 
 
 //等待服务器数据包消息。 
 DatagramPacket receivePacket = new DatagramPacket（receiveData，receiveData.length）; 
 clientSocket.receive（receivePacket）; 
 renderer.recv = new String（receivePacket.getData（））; 
 Log.d（client，从服务器接收的数据包，ETA+ timing.getNow（））; 
} 
} 
 //关闭套接字
 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。）; 
} 
} 
  

清单中启用权限：

 < 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android PC模拟器上运行服务器， / p>

客户&服务器线程运行只是很好，但问题是，我不会得到任何数据之间交换。 客户端未收到任何邮件，且服务器未收到任何邮件。数据包被发送，但没有收到。

我做错了什么？

请帮助我。

提前谢谢。

解决方案

运行你的模拟器后，在命令提示符telnet localhost中输入redir add udp：5000：6000。连接端口号为5000的客户端，并使用端口号6000打开udp服务器。然后可以从udp服务器接收客户端消息。

查看详情

  clientSocket = new DatagramSocket（）; 
 InetAddress IPAddress = InetAddress.getByName（< pc ip>）; //而不是localhost
 
 
 public static final String SERVERIP =127.0.0.1; //'Within'the emulator！ 
 public static final int SERVERPORT = 6000; 
 
 / *检索ServerName * / 
 InetAddress serverAddr = InetAddress.getByName（SERVERIP）; 
 DatagramSocket socket = new DatagramSocket（SERVERPORT，serverAddr）; 
  

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

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

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. :(

The Server java class (RE-EDITED, Server receives msg. from Client):

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.");
    }
}

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.");
    }
}

the Permisions are enabled in the manifest:

<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"/>

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

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 .

What im doing wrong ?

Please help me.
Thank you in advance.

解决方案

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.

Take a look for details

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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