Android 使用Wi-Fi创建P2P连接：消息传递问题

我正在使用Wifi P2P连接，使用下面的教程在两台Android设备之间发送和接收消息

它正在识别附近的设备并与附近的对等方连接。但在我的代码中，在服务器和客户端之间连接成功后，客户端对等方在服务器对等方无法向客户端对等方发送消息后成功地向服务器对等方发送消息，并给出以下异常

04-14 12:31:27.740: E/test(6037): SERVER to CLIENT message sending exception: bind failed: EADDRINUSE (Address already in use)

请帮助查找我的代码有什么问题

这是我的MainActivity.java

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.IntentFilter;
import android.net.wifi.p2p.WifiP2pConfig;
import android.net.wifi.p2p.WifiP2pDevice;
import android.net.wifi.p2p.WifiP2pDeviceList;
import android.net.wifi.p2p.WifiP2pInfo;
import android.net.wifi.p2p.WifiP2pManager;
import android.net.wifi.p2p.WifiP2pManager.ActionListener;
import android.net.wifi.p2p.WifiP2pManager.Channel;
import android.net.wifi.p2p.WifiP2pManager.ConnectionInfoListener;
import android.net.wifi.p2p.WifiP2pManager.PeerListListener;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.WindowManager;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity implements OnClickListener, PeerListListener, ConnectionInfoListener{

WifiP2pManager mManager;
Channel mChannel;
private List<WifiP2pDevice> peers = new ArrayList<WifiP2pDevice>();
BroadcastReceiver mReceiver;
IntentFilter mIntentFilter;
private BroadcastReceiver receiver = null;
private WifiP2pInfo info;
String groupOwnerAddress;

ListView listPeers;
TextView mTextDeviceName, mTextStatus, mTextGroupOwner;
EditText mEditText_message;
Context context;
static String toastmessage;
static String message = "";
boolean isPeerServer;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    context = MainActivity.this;
    getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

    mManager = (WifiP2pManager) getSystemService(Context.WIFI_P2P_SERVICE);
    mChannel = mManager.initialize(this, getMainLooper(), null);
    mReceiver = new WifiP2PBroadCast(mManager, mChannel, this);

    mIntentFilter = new IntentFilter();
    mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION);
    mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION);
    mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION);
    mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION);

    findViewById(R.id.button_search).setOnClickListener(this);
    findViewById(R.id.button_send).setOnClickListener(this);

    listPeers = (ListView) findViewById(R.id.list_peers);
    mTextDeviceName = (TextView) findViewById(R.id.text_device_name);
    mTextStatus = (TextView) findViewById(R.id.text_Status);
    mTextGroupOwner = (TextView) findViewById(R.id.text_group_owner);
    mEditText_message = (EditText) findViewById(R.id.edittext_message);

    listPeers.setOnItemClickListener(new OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> arg0, View arg1, int position, long arg3) {
            // TODO Auto-generated method stub
            connectWithPeers(position);
        }
    });
}

@Override
protected void onResume() {
    // TODO Auto-generated method stub
    super.onResume();
    receiver = new WifiP2PBroadCast(mManager, mChannel, this);
    registerReceiver(mReceiver, mIntentFilter);
    discoverPeers();
}

@Override
protected void onPause() {
    super.onPause();
    unregisterReceiver(mReceiver);
}

public void updateDeviceInfo(WifiP2pDevice device) {
    mTextDeviceName.setText(device.deviceName);
    mTextStatus.setText(getDeviceStatus(device.status));
}

private static String getDeviceStatus(int deviceStatus) {
    switch (deviceStatus) {
        case WifiP2pDevice.AVAILABLE:
            return "Available";
        case WifiP2pDevice.INVITED:
            return "Invited";
        case WifiP2pDevice.CONNECTED:
            return "Connected";
        case WifiP2pDevice.FAILED:
            return "Failed";
        case WifiP2pDevice.UNAVAILABLE:
            return "Unavailable";
        default:
            return "Unknown";
    }
}

@Override
public void onClick(View v) {
    // TODO Auto-generated method stub
    switch (v.getId()) {
        case R.id.button_search:
            discoverPeers();
            break;
        case R.id.button_send:
            sendMessage();
            break;
        default:
            break;
    }

}

public void discoverPeers(){
    mManager.discoverPeers(mChannel, new WifiP2pManager.ActionListener() {
        @Override
        public void onSuccess() {
            Log.e("test", "Discovering Peers Success..");
            if (mManager != null) {
                mManager.requestPeers(mChannel, MainActivity.this);
            }
        }

        @Override
        public void onFailure(int reasonCode) {
           Log.e("test", "Discovering Peers Fail..");
        }
    });
}

public void connectWithPeers(int id) {
    WifiP2pDevice device = peers.get(id);
    WifiP2pConfig config = new WifiP2pConfig();
    config.deviceAddress = device.deviceAddress;
    mManager.connect(mChannel, config, new ActionListener() {

        @Override
        public void onSuccess() {
            //success logic
            Log.e("test", "Connection with peer Success..");
        }

        @Override
        public void onFailure(int reason) {
            //failure logic
            Log.e("test", "Connection with peer Failed..");
        }
    });
}

public void sendMessage() {
    if (!isPeerServer) {
        //Client Peer
        Toast.makeText(MainActivity.this, "client sending message", Toast.LENGTH_SHORT).show();
        new SendMessage().execute(MainActivity.this);
    } else {
        //Server Peer
        Toast.makeText(MainActivity.this, "server sending message", Toast.LENGTH_SHORT).show();
        new FileServerAsyncTask(this, "").execute();
    }

}

//Send message form client to server
public class SendMessage extends AsyncTask {
    @Override
    protected Object doInBackground(Object... arg0) {
        // TODO Auto-generated method stub
        try {
            message = mEditText_message.getText().toString();

            Socket socket = new Socket(info.groupOwnerAddress.getHostAddress(), 8988);
            //Send the message to the server
            OutputStream os = socket.getOutputStream();
            OutputStreamWriter osw = new OutputStreamWriter(os);
            BufferedWriter bw = new BufferedWriter(osw);

            String number = message;

            String sendMessage = number + "\n";
            bw.write(sendMessage);
            bw.flush();
            Log.e("test", "Message sent to the server : "+sendMessage);

            //Get the return message from the server
            InputStream is = socket.getInputStream();
            InputStreamReader isr = new InputStreamReader(is);
            BufferedReader br = new BufferedReader(isr);
            String message = br.readLine();
            Log.e("test", "Message received from the server : " +message);
            socket.close();
        }catch(IOException e){
            Log.e("test", "CLIENT to SERVER message sending exception: "+e.getMessage());
        }finally {
        }
        return null;
    }

    @Override
    protected void onPostExecute(Object result) {
        // TODO Auto-generated method stub
        super.onPostExecute(result);
        Toast.makeText(MainActivity.this, "MESSAGE: "+message, Toast.LENGTH_SHORT).show();
    }

}

@Override
public void onConnectionInfoAvailable(WifiP2pInfo wifiP2pInfo) {
    // TODO Auto-generated method stub
    Log.e("test", "..onConnectionInfoAvailable..");
    info = wifiP2pInfo;
    try {
        groupOwnerAddress = wifiP2pInfo.groupOwnerAddress.getHostAddress();
    } catch (Exception e) {
        // TODO: handle exception
        Log.e("test", "Owner Info null");
    }

    if (info.groupFormed && info.isGroupOwner) {
        Log.e("test", "GOT INFORMATION FROM PEERS..");
        new FileServerAsyncTask(this, "").execute();
    }
    if (wifiP2pInfo.isGroupOwner) {
        isPeerServer = true;
    } else {
        isPeerServer = false;
    }
    mTextGroupOwner.setText("Is group owner? ---- "+((wifiP2pInfo.isGroupOwner == true) ? "yes" : "no"));
}

@Override
public void onPeersAvailable(WifiP2pDeviceList peerList) {
    // TODO Auto-generated method stub
    Log.e("test", "NUMBER OF PEERS AVAILABLE: ----- "+peerList.getDeviceList().size());
    peers.clear();
    peers.addAll(peerList.getDeviceList());

    String[] devices = new String[peerList.getDeviceList().size()];
     for (int i = 0; i < devices.length; i++) {
        devices[i] = peers.get(i).deviceName.toString();
     }

     try {
         ArrayAdapter<String> adapter = new ArrayAdapter<String>(MainActivity.this, R.layout.simplerow, devices);
         listPeers.setAdapter(adapter); 
     }catch (Exception e) {
        // TODO: handle exception
        Log.e("test", "EXCEPTION: "+e.toString());
     }

}

//Send message form server to client
public class FileServerAsyncTask extends AsyncTask<Object, Object, Object> {
    private Context context;
    String message;
    public FileServerAsyncTask(Context context, String statusText) {
        this.context = context;
    }
    @Override
    protected Object doInBackground(Object... arg0) {
        // TODO Auto-generated method stub
        Socket socket = null;
        try {

            ServerSocket serverSocket = new ServerSocket(8988);
                //Reading the message from the client
                socket = serverSocket.accept();
                InputStream is = socket.getInputStream();
                InputStreamReader isr = new InputStreamReader(is);
                BufferedReader br = new BufferedReader(isr);
                String number = br.readLine();
                toastmessage = number;
                Log.e("test", "Message received from client is "+number);

                //Multiplying the number by 2 and forming the return message
                String returnMessage;
                returnMessage = "Return message from Server..";//String.valueOf(returnValue) + "\n";

                //Sending the response back to the client.
                OutputStream os = socket.getOutputStream();
                OutputStreamWriter osw = new OutputStreamWriter(os);
                BufferedWriter bw = new BufferedWriter(osw);
                bw.write(returnMessage);
                Log.e("test", "Message sent to the client is "+returnMessage);
                bw.flush();

        }catch (Exception e){
            Log.e("test", "SERVER to CLIENT message sending exception: "+e.getMessage());
        }finally {
            try{
                socket.close();
            }
            catch(Exception e){}
        }
        return null;
    }

    @Override
    protected void onPostExecute(Object result) {
        // TODO Auto-generated method stub
        Toast.makeText(MainActivity.this, "Message from Client: "+toastmessage, Toast.LENGTH_SHORT).show();
    }

}

}

这是AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.suresh.wifi_p2p_demo"
android:versionCode="1"
android:versionName="1.0" >

<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

<uses-sdk
    android:minSdkVersion="15"
    android:targetSdkVersion="25" />

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name=".MainActivity"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.suresh.wifi_p2p_demo"
android:versionCode="1"
android:versionName="1.0" >

<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

<uses-sdk
    android:minSdkVersion="15"
    android:targetSdkVersion="25" />

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name=".MainActivity"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>