java - Android 蓝牙套接字 IOException : 'read failed, socket might be closed or timeout'

Question

我有一个蓝牙 Remote (我想是自拍杆)通过蓝牙与我的手机连接。它可以工作，它可以拍照，但我想在我的应用程序中接收来自 Remote 的信号来远程控制音乐。

问题:创建套接字后，如果没有 IOException，我无法连接到它。

这是所有代码:

public class MainActivity extends Activity {

BluetoothAdapter btAdapter;
public static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
protected static final int SUCCESS_CONNECT = 0;
protected static final int MESSAGE_READ = 1;
IntentFilter filter;
String tag = "debugging";
Handler mHandler = new Handler(){
    @Override
    public void handleMessage(Message msg) {
        // TODO Auto-generated method stub
        Log.i(tag, "in handler");
        super.handleMessage(msg);
        switch(msg.what){
        case SUCCESS_CONNECT:
            // DO something
            ConnectedThread connectedThread = new ConnectedThread((BluetoothSocket)msg.obj);
            Toast.makeText(getApplicationContext(), "CONNECT", 0).show();
            String s = "successfully connected";
            connectedThread.write(s.getBytes());
            Log.i(tag, "connected");
            break;
        case MESSAGE_READ:
            byte[] readBuf = (byte[])msg.obj;
            String string = new String(readBuf);
            Toast.makeText(getApplicationContext(), string, 0).show();
            break;
        }
    }
};
@SuppressLint("NewApi")
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    try{
     btAdapter = BluetoothAdapter.getDefaultAdapter();
    BluetoothDevice device = getDeviceByName("AB Shutter 3");

    ConnectThread connect = new ConnectThread(device);
    connect.start();


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

    }

}

private BluetoothDevice getDeviceByName(String printerName) 
{
    Set<BluetoothDevice> pairedDevices = BluetoothAdapter.getDefaultAdapter().getBondedDevices();

    BluetoothDevice remoteDevice;

    for (BluetoothDevice device : pairedDevices) 
    {
        if (device.getName() == null)
            continue;
        if (device.getName().contains(printerName)) 
        {
            Log.e("","device name: "+device.getName());
            remoteDevice = device;
            return remoteDevice;
        }
    }
    return null;
}
private class ConnectThread extends Thread {

        private final BluetoothSocket mmSocket;
        private final BluetoothDevice mmDevice;

        public ConnectThread(BluetoothDevice device) {
            // Use a temporary object that is later assigned to mmSocket,
            // because mmSocket is final
            BluetoothSocket tmp = null;
            mmDevice = device;
            Log.i(tag, "construct");
            // 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(MY_UUID);

            } catch (IOException e) { 
                Log.i(tag, "get socket failed");
                e.printStackTrace();

            }
            mmSocket = tmp;
        }

        public void run() {
            try {   
            // Cancel discovery because it will slow down the connection
            btAdapter.cancelDiscovery();
            Log.i(tag, "connect - run");

                mmSocket.connect();
                Log.i(tag, "connect - succeeded");
            } catch (Exception connectException) {  
                Log.i(tag, "connect failed");
                // Unable to connect; close the socket and get out
                 connectException.printStackTrace();
                return;
            }

            // Do work to manage the connection (in a separate thread)

            mHandler.obtainMessage(SUCCESS_CONNECT, mmSocket).sendToTarget();
        }

    }

    private class ConnectedThread extends Thread {
        private final BluetoothSocket mmSocket;
        private final InputStream mmInStream;
        private final OutputStream mmOutStream;

        public ConnectedThread(BluetoothSocket socket) {
            mmSocket = socket;
            InputStream tmpIn = null;
            OutputStream tmpOut = null;

            // Get the input and output streams, using temp objects because
            // member streams are final
            try {
                tmpIn = socket.getInputStream();
                tmpOut = socket.getOutputStream();
            } catch (IOException e) { }

            mmInStream = tmpIn;
            mmOutStream = tmpOut;
        }

        public void run() {
            byte[] buffer;  // buffer store for the stream
            int bytes; // bytes returned from read()

            // Keep listening to the InputStream until an exception occurs
            while (true) {
                try {
                    // Read from the InputStream
                    buffer = new byte[1024];
                    bytes = mmInStream.read(buffer);
                    // Send the obtained bytes to the UI activity
                    mHandler.obtainMessage(MESSAGE_READ, bytes, -1, buffer)
                            .sendToTarget();

                } catch (Exception e) {
                    e.printStackTrace();
                    break;
                }
            }
        }

        public void write(byte[] bytes) {
            try {
                mmOutStream.write(bytes);
            } catch (IOException e) { }
        }
    }
}

错误出现在第 131 行，ConnectThread run()

    try {   
            // Cancel discovery because it will slow down the connection
            btAdapter.cancelDiscovery();
            Log.i(tag, "connect - run");

                mmSocket.connect();                       //Here it fails
                Log.i(tag, "connect - succeeded");
            } catch (Exception connectException) {  
                Log.i(tag, "connect failed");
                // Unable to connect; close the socket and get out
                 connectException.printStackTrace();
                return;
            }

错误显示:

有人以前遇到过这个错误并能指出我正确的方向吗？

Answer 1

这不是错误，而是警告。警告发生后您是否会失去某种功能？如果没有，听起来你无法控制它，但根据这个答案中的几个人的说法，也不需要担心它:https://stackoverflow.com/a/24229604/3299157