Android应用蓝牙收发数据失败: Socket意外关闭

Question

我的蓝牙代码无法正确接收我发送的数据。上面说插座是关着的。

ADB错误：

03-24 11:09:01.189 6826-7480/com.team980.thunderscout W/System.err: java.io.IOException: bt socket closed, read return: -1
03-24 11:09:01.190 6826-7480/com.team980.thunderscout W/System.err:     at android.bluetooth.BluetoothSocket.read(BluetoothSocket.java:442)
03-24 11:09:01.190 6826-7480/com.team980.thunderscout W/System.err:     at android.bluetooth.BluetoothInputStream.read(BluetoothInputStream.java:96)

                                                                [ 03-24 11:09:01.190 25999:26018 I/         ]
                                                                [JSR82][JBT] JBT bt_handle_session_disconnect_ind parms.ps_type:01
03-24 11:09:01.190 6826-7480/com.team980.thunderscout W/System.err:     at java.io.InputStreamReader.read(InputStreamReader.java:231)
03-24 11:09:01.190 6826-7480/com.team980.thunderscout W/System.err:     at java.io.InputStreamReader.read(InputStreamReader.java:181)
03-24 11:09:01.190 6826-7480/com.team980.thunderscout W/System.err:     at com.team980.thunderscout.thread.ServerReadThread.run(ServerReadThread.java:48)

ServerReadThread.java：

package com.team980.thunderscout.thread;

import android.bluetooth.BluetoothSocket;
import android.content.Context;
import android.os.Handler;
import android.os.Looper;
import android.widget.Toast;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

public class ServerReadThread extends Thread {
private final BluetoothSocket mmSocket;

private Context context;

public ServerReadThread(BluetoothSocket socket, Context context) {
    mmSocket = socket;

    this.context = context;
}

public void run() {

    InputStream is;

    try {
        is = mmSocket.getInputStream();
    } catch (IOException e) {
        e.printStackTrace();
        return;
    }

    InputStreamReader isr;

    try {
        isr = new InputStreamReader(is, "UTF-8");
    } catch (Exception e) {
        e.printStackTrace();
        return;
    }

    StringBuilder sb = new StringBuilder();

    try {

        int data = isr.read(); //TODO somehow the socket closes here, returning -1! This is bad!

        while (data != -1) {
            char theChar = (char) data;
            sb.append(theChar);
            data = isr.read();
        }

    } catch (IOException e) {
        e.printStackTrace();
    }

    String message = sb.toString();

    try {
        isr.close();
    } catch (IOException e) {
        e.printStackTrace();
    }

    postToastMessage("Found message: " + message); //TODO print result

    // Send the obtained bytes to the UI activity - TODO put it in a DB
    /*Intent broadcastIntent = new Intent();
    broadcastIntent.setAction("ThunderScout_RefreshData");
    context.sendBroadcast(broadcastIntent);*/
}

/* Call this from the main activity to shutdown the connection */
public void cancel() {
    try {
        mmSocket.close();
    } catch (IOException e) {
    }
}

public void postToastMessage(final String message) {
    Handler handler = new Handler(Looper.getMainLooper());

    handler.post(new Runnable() {

        @Override
        public void run() {
            Toast.makeText(context, message, Toast.LENGTH_LONG).show();
        }
    });
}
}

ServerAcceptThread：

package com.team980.thunderscout.thread;

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothServerSocket;
import android.bluetooth.BluetoothSocket;
import android.content.Context;
import android.os.Handler;
import android.os.Looper;
import android.widget.Toast;

import com.team980.thunderscout.bluetooth.BluetoothInfo;

import java.io.IOException;
import java.util.UUID;

public class ServerAcceptThread extends Thread {
private final BluetoothServerSocket mmServerSocket;

private BluetoothAdapter mBluetoothAdapter;

private Context context;

public ServerAcceptThread(Context context) {
    // Use a temporary object that is later assigned to mmServerSocket,
    // because mmServerSocket is final
    BluetoothServerSocket tmp = null;

    mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();

    try {
        // MY_UUID is the app's UUID string, also used by the client code
        tmp = mBluetoothAdapter.listenUsingRfcommWithServiceRecord(BluetoothInfo.SERVICE_NAME, UUID.fromString(BluetoothInfo.UUID));
    } catch (IOException e) {
    }
    mmServerSocket = tmp;

    this.context = context;
}

public void run() {
    // Keep listening until exception occurs
    while (true) {
        BluetoothSocket socket;
        try {
            postToastMessage("Listening for incoming connections");
            socket = mmServerSocket.accept(); //TODO find cause of error
        } catch (IOException e) {
            e.printStackTrace();
            break;
        }
        // If a connection was accepted
        if (socket != null) {
            // Do work to manage the connection (in a separate thread)

            postToastMessage("Connected to " + socket.getRemoteDevice().getName());

            ServerReadThread readThread = new ServerReadThread(socket, context);
            readThread.start();
        }
    }
}

/**
 * Will cancel the listening socket, and cause the thread to finish
 */
public void cancel() {
    try {
        mmServerSocket.close();
    } catch (IOException e) {

    }
}

public void postToastMessage(final String message) {
    Handler handler = new Handler(Looper.getMainLooper());

    handler.post(new Runnable() {

        @Override
        public void run() {
            Toast.makeText(context, message, Toast.LENGTH_LONG).show();
        }
    });
}
}

ClientConnectionThread：

package com.team980.thunderscout.thread;

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.Context;
import android.os.Handler;
import android.os.Looper;
import android.widget.Toast;

import com.team980.thunderscout.bluetooth.BluetoothInfo;
import com.team980.thunderscout.data.ScoutData;

import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.util.UUID;

public class ClientConnectionThread extends Thread {
private final BluetoothSocket mmSocket;

private BluetoothAdapter mBluetoothAdapter;

private ScoutData scoutData;

private Context context;


public ClientConnectionThread(BluetoothDevice device, ScoutData data, Context context) {
    // Use a temporary object that is later assigned to mmSocket,
    // because mmSocket is final
    BluetoothSocket tmp = null;

    mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();

    // Get a BluetoothSocket to connect with the given BluetoothDevice
    try {
        // MY_UUID is the app's UUID string, also used by the server code
        tmp = device.createRfcommSocketToServiceRecord(UUID.fromString(BluetoothInfo.UUID));
    } catch (IOException e) { }
    mmSocket = tmp;

    scoutData = data;

    this.context = context;
}

public void run() {
    // Cancel discovery because it will slow down the connection
    mBluetoothAdapter.cancelDiscovery();

    try {
        // Connect the device through the socket. This will block
        // until it succeeds or throws an exception
        mmSocket.connect();
    } catch (IOException connectException) {
        // Unable to connect; close the socket and get out
        try {
            mmSocket.close();
        } catch (IOException closeException) {
            closeException.printStackTrace();
        }
        return;
    }

    postToastMessage("Successfully connected to server device");

    try {
        OutputStream os = mmSocket.getOutputStream();
        OutputStreamWriter osw = new OutputStreamWriter(os, "UTF-8");

        postToastMessage("Writing data: " + scoutData.getTeamNumber());

        osw.write(scoutData.getTeamNumber());

        postToastMessage("Send complete!");

        osw.close();
       //mmSocket.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

/** Will cancel an in-progress connection, and close the socket */
public void cancel() {
    try {
        mmSocket.close();
    } catch (IOException e) { }
}

public void postToastMessage(final String message) {
    Handler handler = new Handler(Looper.getMainLooper());

    handler.post(new Runnable() {

        @Override
        public void run() {
            Toast.makeText(context, message, Toast.LENGTH_LONG).show();
        }
    });
}
}

我已经为此工作了几个小时，但没有结果。ServerAcceptThread不断地在后台运行，并等待另一台设备上的ClientConnectThread与其联系。然后，ServerAcceptThread产生一个ServerReadThread来读取ClientConnectThread发送的数据，但它每次都无法读取数据。

ServerAcceptThread由服务管理，ClientConnectThreads通过“发送”按钮在用户交互时产生。

如果你需要更多的信息，我很乐意提供。

Answer 1

这是一个愚蠢的错误消息，就像这个领域的其他消息一样。它应该说的是对等体已经关闭了连接。插座仍处于打开状态。在关闭的套接字上调用read()，或者当read()在另一个线程中执行时将其关闭，这将(应该)导致异常。