我正在开发一个应用程序，我正在使用蓝牙连接到设备，该设备适用于所有 android 版本，但三星 Galaxy Tab 2 10.1 存在一些问题。 问题：- 如果设备在一段时间后关闭，我的应用程序检测到然后开始搜索远程设备。但应用程序无法找到设备（打开时）。当我再次在这里开始正常搜索时，我也有一个正常的设备列表活动，它找到了设备并正确连接到它。 代码：-- 我的连接代码如下，我使用的是低级连接而不是串行端口。我遵循的步骤：1）查找蓝牙设备（获取mac）2）启动HHDService.start（）；3）HHDService.connect（蓝牙设备）；
主要问题是设备断开后应用程序无法找到设备...
public class HHDService {
// Debugging
private static final String TAG = "HHDService";
private static final boolean D = true;
boolean isRequestSend = true;
// Unique UUID for this application
//private static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
private BluetoothSocket mmSocket = null;
private InputStream mmInStream = null;
private OutputStream mmOutStream = null;
// Member fields
private final BluetoothAdapter mAdapter;
private Handler mHandler;
//private AcceptThread mAcceptThread;
private ConnectThread mConnectThread;
private ConnectedThread mConnectedThread;
private int mState;
private long waitTime = 15000;
// Constants 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
public static final int STATE_SLEEP = 4; // now connected to a remote
// device
private Context mContext;
/**
* 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 HHDBapiBTService(Context context, Handler handler) {
mAdapter = BluetoothAdapter.getDefaultAdapter();
mState = STATE_NONE;
mHandler = handler;
mContext = context;
}
/**
* Set the current state of the chat connection
*
* @param state
* An integer defining the current connection state
*/
public 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(GlobalValues.MESSAGE_STATE_CHANGE, state, -1)
.sendToTarget();
}
/**
* Return the current connection state.
*/
public synchronized int getState() {
return mState;
}
public void setHandler(Handler handler) {
mHandler = handler;
}
/**
* 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(true);
mConnectThread = null;
}
// Cancel any thread currently running a connection
if (mConnectedThread != null) {
mConnectedThread.cancel();
mConnectedThread = null;
}
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;
}
// Start the thread to manage the connection and perform transmissions
mConnectedThread = new ConnectedThread(socket);
mConnectedThread.start();
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;
}
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) {
if(getState() == STATE_SLEEP){
connectionLost();
return;
}
// Create temporary object
ConnectedThread r;
// Synchronize a copy of the ConnectedThread
synchronized (this) {
if (mState != STATE_CONNECTED)
return;
r = mConnectedThread;
}
// Perform the write unsynchronized
r.write(out);
}
public void closeConnection(){
ConnectedThread r;
// Synchronize a copy of the ConnectedThread
synchronized (this) {
if (mState != STATE_CONNECTED)
return;
r = mConnectedThread;
}
r.cancel();
}
/**
* Indicate that the connection attempt failed and notify the UI Activity.
*/
private void connectionFailed() {
if(getState() != STATE_LISTEN){
setState(STATE_LISTEN);
}
}
/**
* 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
setState(STATE_SLEEP);
}
/**
* 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
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
HHDService.this.start();
return;
}
// Reset the ConnectThread because we're done
synchronized (HHDService.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);
}
}
}*/
private class ConnectThread extends Thread {
private BluetoothSocket mmSocket;
private final BluetoothDevice mmDevice;
public ConnectThread(BluetoothDevice device) {
mmDevice = device;
}
@SuppressLint("NewApi")
protected boolean simpleComm(Integer port) {
// byte [] inputBytes = null;
// The documents tell us to cancel the discovery process.
mAdapter.cancelDiscovery();
Log.d(this.toString(), "Port = " + port);
try {
Method m = mmDevice.getClass().getMethod("createRfcommSocket",
new Class[] { int.class });
mmSocket = (BluetoothSocket) m.invoke(mmDevice, port);
// debug check to ensure socket was set.
assert (mmSocket != null) : "Socket is Null";
mAdapter.cancelDiscovery();
// attempt to connect to device
mmSocket.connect();
try {
Log.d(this.toString(),
"************ CONNECTION SUCCEES! *************");
// Reset the ConnectThread because we're done
synchronized (HHDService.this) {
mConnectThread = null;
}
connected(mmSocket, mmDevice);
return true;
} finally {
// close the socket and we are done.
// //mmSocket.close();
}
// IOExcecption is thrown if connect fails.
} catch (IOException ex) {
Log.e(this.toString(), "IOException " + ex.getMessage());
if (port == 256) {
connectionFailed();
try {
mmSocket.close();
mmSocket = null;
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
} catch (NoSuchMethodException ex) {
Log.e(this.toString(),
"NoSuchMethodException " + ex.getMessage());
} catch (IllegalAccessException ex) {
Log.e(this.toString(),
"IllegalAccessException " + ex.getMessage());
} catch (InvocationTargetException ex) {
Log.e(this.toString(),
"InvocationTargetException " + ex.getMessage());
}catch (NullPointerException ex) {
Log.e(this.toString(),
"NullPointerException " + ex.getMessage());
}
return false;
}
public void run() {
for (Integer port = 1; port <= 256; port++) {
if (simpleComm(Integer.valueOf(port)))
break;
}
}
public void cancel() {
if (mmSocket != null) {
try {
mmSocket.close(); mmSocket = null;
} catch (IOException e) {
Log.e(TAG, "close() of connect secure socket failed", e);
}
}
}
public void cancel(boolean val) {
if (mmSocket != null) {
try {
mmSocket.close(); mmSocket = null;
} catch (IOException e) {
Log.e(TAG, "close() of connect secure 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 Logger logger;
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);
}
logger = Logger.getInstance();
mmInStream = tmpIn;
mmOutStream = tmpOut;
}
@Override
public void run() {
Log.i(TAG, "BEGIN mConnectedThread");
byte[] buffer = new byte[1024];
int bytes;
byte commandByte = 00;
//Logic to parse incoming data
};
}
}