Android蓝牙java.io.IOException：bt socket关闭，读取返回：-1

我正在尝试编写一个代码，该代码仅连接到运行Android 5.0 KitKat的设备上的（仅用于）配对设备。 无论我尝试过多少东西，我仍然会遇到这个错误。 这是我尝试的最后一个代码，它似乎正在做我见过人们报告成功的一切。

谁能指出我做错了什么？

java.io.IOException: bt socket closed, read return: -1 at android.bluetooth.BluetoothSocket.read(BluetoothSocket.java:517) at android.bluetooth.BluetoothInputStream.read(BluetoothInputStream.java:96) at java.io.InputStream.read(InputStream.java:162) at biometricreader.BluetoothReaderService$ConnectedThread.run(BluetoothReaderService.java:415) 

我的java代码是

 /** * This class does all the work for setting up and managing Bluetooth * connections with other devices. It has a thread that listens for * incoming connections, a thread for connecting with a device, and a * thread for performing data transmissions when connected. */ public class BluetoothReaderService { // Debugging private static final String TAG = "BluetoothChatService"; private static final boolean D = true; // Name for the SDP record when creating server socket private static final String NAME = "BluetoothChat"; // Unique UUID for this application private static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"); // Member fields private final BluetoothAdapter mAdapter; private final Handler mHandler; private AcceptThread mAcceptThread; private ConnectThread mConnectThread; private ConnectedThread mConnectedThread; private int mState; private InputStream mInStream; private OutputStream mOutStream; // APPConstants that indicate the current connection state public static final int STATE_NONE = 0; // we're doing nothing public static final int STATE_LISTEN = 1; // now listening for incoming connections public static final int STATE_CONNECTING = 2; // now initiating an outgoing connection public static final int STATE_CONNECTED = 3; // now connected to a remote device /** * Constructor. Prepares a new BluetoothChat session. * @param context The UI Activity Context * @param handler A Handler to send messages back to the UI Activity */ public BluetoothReaderService(Context context, Handler handler) { mAdapter = BluetoothAdapter.getDefaultAdapter(); mState = STATE_NONE; mHandler = handler; } /** * Set the current state of the chat connection * @param state An integer defining the current connection state */ private synchronized void setState(int state) { if (D) Log.d(TAG, "setState() " + mState + " -> " + state); mState = state; // Give the new state to the Handler so the UI Activity can update mHandler.obtainMessage(Constant.MESSAGE_STATE_CHANGE, state, -1).sendToTarget(); } /** * Return the current connection state. */ public synchronized int getState() { return mState; } /** * Start the chat service. Specifically start AcceptThread to begin a * session in listening (server) mode. Called by the Activity onResume() */ public synchronized void start() { if (D) Log.d(TAG, "start"); // Cancel any thread attempting to make a connection if (mConnectThread != null) {mConnectThread.cancel(); mConnectThread = null;} // Cancel any thread currently running a connection if (mConnectedThread != null) {mConnectedThread.cancel(); mConnectedThread = null;} // Start the thread to listen on a BluetoothServerSocket if (mAcceptThread == null) { mAcceptThread = new AcceptThread(); mAcceptThread.start(); } setState(STATE_LISTEN); } /** * Start the ConnectThread to initiate a connection to a remote device. * @param device The BluetoothDevice to connect */ public synchronized void connect(BluetoothDevice device) { if (D) Log.d(TAG, "connect to: " + device); // Cancel any thread attempting to make a connection if (mState == STATE_CONNECTING) { if (mConnectThread != null) {mConnectThread.cancel(); mConnectThread = null;} } // Cancel any thread currently running a connection if (mConnectedThread != null) {mConnectedThread.cancel(); mConnectedThread = null;} // Start the thread to connect with the given device mConnectThread = new ConnectThread(device); mConnectThread.start(); setState(STATE_CONNECTING); } /** * Start the ConnectedThread to begin managing a Bluetooth connection * @param socket The BluetoothSocket on which the connection was made * @param device The BluetoothDevice that has been connected */ public synchronized void connected(BluetoothSocket socket, BluetoothDevice device) { if (D) Log.d(TAG, "connected"); // Cancel the thread that completed the connection if (mConnectThread != null) {mConnectThread.cancel(); mConnectThread = null;} // Cancel any thread currently running a connection if (mConnectedThread != null) {mConnectedThread.cancel(); mConnectedThread = null;} // Cancel the accept thread because we only want to connect to one device if (mAcceptThread != null) {mAcceptThread.cancel(); mAcceptThread = null;} // Start the thread to manage the connection and perform transmissions mConnectedThread = new ConnectedThread(socket); mConnectedThread.start(); // Send the name of the connected device back to the UI Activity Message msg = mHandler.obtainMessage(Constant.MESSAGE_DEVICE_NAME); Bundle bundle = new Bundle(); bundle.putString(Constant.DEVICE_NAME, device.getName()); msg.setData(bundle); mHandler.sendMessage(msg); setState(STATE_CONNECTED); } /** * Stop all threads */ public synchronized void stop() { if (D) Log.d(TAG, "stop"); if (mConnectThread != null) {mConnectThread.cancel(); mConnectThread = null;} if (mConnectedThread != null) {mConnectedThread.cancel(); mConnectedThread = null;} if (mAcceptThread != null) {mAcceptThread.cancel(); mAcceptThread = null;} setState(STATE_NONE); } /** * Write to the ConnectedThread in an unsynchronized manner * @param out The bytes to write * @see ConnectedThread#write(byte[]) */ public void write(byte[] out) { // Create temporary object ConnectedThread r; // Synchronize a copy of the ConnectedThread synchronized (this) { if (mState != STATE_CONNECTED) { Log.d(""+getClass(),"bluetoth reader service mState ***** " + mState); return ; } r = mConnectedThread; } // Perform the write unsynchronized r.write(out); } /** * CGPL-17 [satuti] to detect state of device 5/25/2016 */ public int writeReturn(byte[] out) { // Create temporary object ConnectedThread r; // Synchronize a copy of the ConnectedThread synchronized (this) { if (mState != STATE_CONNECTED) { Log.d(""+getClass(),"bluetoth reader service mState ***** " + mState); return mState; } r = mConnectedThread; } // Perform the write unsynchronized r.write(out); return mState; } /** * Indicate that the connection attempt failed and notify the UI Activity. */ private void connectionFailed() { setState(STATE_LISTEN); // Send a failure message back to the Activity Message msg = mHandler.obtainMessage(Constant.MESSAGE_TOAST); Bundle bundle = new Bundle(); bundle.putString(Constant.TOAST, "Unable to connect device"); msg.setData(bundle); mHandler.sendMessage(msg); } /** * Indicate that the connection was lost and notify the UI Activity. */ private void connectionLost() { setState(STATE_LISTEN); // Send a failure message back to the Activity Message msg = mHandler.obtainMessage(Constant.MESSAGE_TOAST); Bundle bundle = new Bundle(); bundle.putString(Constant.TOAST, "Device connection was lost"); msg.setData(bundle); mHandler.sendMessage(msg); } /** * This thread runs while listening for incoming connections. It behaves * like a server-side client. It runs until a connection is accepted * (or until cancelled). */ private class AcceptThread extends Thread { // The local server socket private final BluetoothServerSocket mmServerSocket; public AcceptThread() { BluetoothServerSocket tmp = null; // Create a new listening server socket try { tmp = mAdapter.listenUsingRfcommWithServiceRecord(NAME, MY_UUID); } catch (IOException e) { Log.e(TAG, "listen() failed", e); } mmServerSocket = tmp; } public void run() { if (D) Log.d(TAG, "BEGIN mAcceptThread" + this); setName("AcceptThread"); BluetoothSocket socket = null; // Listen to the server socket if we're not connected while (mState != STATE_CONNECTED) { try { // This is a blocking call and will only return on a // successful connection or an exception socket = mmServerSocket.accept(); } catch (IOException e) { Log.e(TAG, "accept() failed", e); break; } // If a connection was accepted if (socket != null) { synchronized (BluetoothReaderService.this) { switch (mState) { case STATE_LISTEN: case STATE_CONNECTING: // Situation normal. Start the connected thread. connected(socket, socket.getRemoteDevice()); break; case STATE_NONE: case STATE_CONNECTED: // Either not ready or already connected. Terminate new socket. try { socket.close(); } catch (IOException e) { Log.e(TAG, "Could not close unwanted socket", e); } break; } } } } if (D) Log.i(TAG, "END mAcceptThread"); } public void cancel() { if (D) Log.d(TAG, "cancel " + this); try { mmServerSocket.close(); } catch (IOException e) { Log.e(TAG, "close() of server failed", e); } } } /** * This thread runs while attempting to make an outgoing connection * with a device. It runs straight through; the connection either * succeeds or fails. */ private class ConnectThread extends Thread { private final BluetoothSocket mmSocket; private final BluetoothDevice mmDevice; public ConnectThread(BluetoothDevice device) { mmDevice = device; BluetoothSocket tmp = null; // Get a BluetoothSocket for a connection with the // given BluetoothDevice try { tmp = device.createRfcommSocketToServiceRecord(MY_UUID); } catch (IOException e) { Log.e(TAG, "create() failed", e); } mmSocket = tmp; } public void run() { Log.i(TAG, "BEGIN mConnectThread"); setName("ConnectThread"); // Always cancel discovery because it will slow down a connection mAdapter.cancelDiscovery(); // Make a connection to the BluetoothSocket try { // This is a blocking call and will only return on a // successful connection or an exception if(mmSocket == null){ Log.e(TAG, "mmSocket == null"); } mmSocket.connect(); } catch (IOException e) { connectionFailed(); // Close the socket try { mmSocket.close(); } catch (IOException e2) { Log.e(TAG, "unable to close() socket during connection failure", e2); } // Start the service over to restart listening mode BluetoothReaderService.this.start(); return; } // Reset the ConnectThread because we're done synchronized (BluetoothReaderService.this) { mConnectThread = null; } // Start the connected thread connected(mmSocket, mmDevice); } public void cancel() { try { mmSocket.close(); } catch (IOException e) { Log.e(TAG, "close() of connect socket failed", e); } } } /** * This thread runs during a connection with a remote device. * It handles all incoming and outgoing transmissions. */ private class ConnectedThread extends Thread { private final BluetoothSocket mmSocket; private final InputStream mmInStream; private final OutputStream mmOutStream; public ConnectedThread(BluetoothSocket socket) { Log.d(TAG, "create ConnectedThread"); mmSocket = socket; InputStream tmpIn = null; OutputStream tmpOut = null; // Get the BluetoothSocket input and output streams try { tmpIn = socket.getInputStream(); tmpOut = socket.getOutputStream(); } catch (IOException e) { Log.e(TAG, "temp sockets not created", e); } mmInStream = tmpIn; mmOutStream = tmpOut; mInStream = tmpIn; mOutStream = tmpOut; } public void run() { Log.i(TAG, "BEGIN mConnectedThread"); byte[] buffer = new byte[1024]; int bytes; // Keep listening to the InputStream while connected while (true) { try { // Read from the InputStream bytes = mmInStream.read(buffer); // Send the obtained bytes to the UI Activity mHandler.obtainMessage(Constant.MESSAGE_READ, bytes, -1, buffer) .sendToTarget(); } catch (IOException e) { Log.e(TAG, "disconnected", e); connectionLost(); break; } } } /** * Write to the connected OutStream. * @param buffer The bytes to write */ public void write(byte[] buffer) { try { mmOutStream.write(buffer); // Share the sent message back to the UI Activity mHandler.obtainMessage(Constant.MESSAGE_WRITE, -1, -1, buffer) .sendToTarget(); } catch (IOException e) { Log.e(TAG, "Exception during write", e); } } public void cancel() { try { mmSocket.close(); } catch (IOException e) { Log.e(TAG, "close() of connect socket failed", e); } } } public boolean writestream(byte[] buffer) { boolean ret=false; if(mState == STATE_CONNECTED) { try { mOutStream.write(buffer); ret=true; } catch (IOException e) { Log.e(TAG, "Exception during write", e); } } return ret; } public int readstream(byte[] buffer) { int bytes=0; if(mState == STATE_CONNECTED) { try { bytes=mInStream.read(buffer); } catch (IOException e) { Log.e(TAG, "Exception during read", e); } } return bytes; } } 

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 **i am getting this error on my class ConnectedThread // Read from the InputStream bytes = mmInStream.read(buffer);** 

私有类ConnectedThread扩展Thread {

  private final BluetoothSocket mmSocket; private final InputStream mmInStream; private final OutputStream mmOutStream; public ConnectedThread(BluetoothSocket socket) { Log.e(TAG, "create ConnectedThread"); mmSocket = socket; InputStream tmpIn = null; OutputStream tmpOut = null; // Get the BluetoothSocket input and output streams try { tmpIn = socket.getInputStream(); tmpOut = socket.getOutputStream(); } catch (IOException e) { Log.e(TAG, "temp sockets not created", e); } mmInStream = tmpIn; mmOutStream = tmpOut; mInStream = tmpIn; mOutStream = tmpOut; } public void run() { Log.i(TAG, "BEGIN mConnectedThread"); byte[] buffer = new byte[1024]; int bytes; // Keep listening to the InputStream while connected while (true) { try { // Read from the InputStream bytes = mmInStream.read(buffer); // Send the obtained bytes to the UI Activity mHandler.obtainMessage(Constant.MESSAGE_READ, bytes, -1, buffer) .sendToTarget(); } catch (IOException e) { Log.e(TAG, "disconnected", e); connectionLost(); break; } } } /** * Write to the connected OutStream. * @param buffer The bytes to write */ public void write(byte[] buffer) { try { mmOutStream.write(buffer); // Share the sent message back to the UI Activity mHandler.obtainMessage(Constant.MESSAGE_WRITE, -1, -1, buffer) .sendToTarget(); } catch (IOException e) { Log.e(TAG, "Exception during write", e); } } public void cancel() { try { mmSocket.close(); } catch (IOException e) { Log.e(TAG, "close() of connect socket failed", e); } } } 

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