我正在创建一个将收据打印到蓝牙外置打印机的应用程序！我能够成功配置他们的SDK并能够打印到外部设备！我实现的方法是，当我点击我的打印按钮时，它搜索配对设备，当选择打印机时，它将mac id保存到prefrence并调用打印功能！下次点击打印按钮时，它不会搜索，因为它有设备的mac Id并要求打印！
我面临的问题是，当我第一次点击打印按钮它工作和打印时，当我再次按下设备连接丢失，无法连接烤面包弹出，没有打印发生！当我再次连接它打印成功。这继续发生！如果我让设备闲置一段时间，那么打印也会发生！当蓝牙关闭然后打开时也会发生打印!!
我的蓝牙服务：
SSH活动代码：
http://52.221.44.206/mobeeload/PrintBluetooth.java
记录错误：
public class BluetoothService {
// Debugging
private static final String TAG = "BluetoothService";
private static final boolean DEBUG = true;
// Name for the SDP record when creating server socket
private static final String NAME = "ZJPrinter";
//UUID must be this
// Unique UUID for this application
private static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
// Member fields
private BluetoothAdapter mAdapter;
private Handler mHandler;
private AcceptThread mAcceptThread;
private ConnectThread mConnectThread;
private ConnectedThread mConnectedThread;
private int mState;
// 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 String ErrorMessage = "No_Error_Message";
/**
* Constructor. Prepares a new BTPrinter session.
* @param context The UI Activity Context
* @param handler A Handler to send messages back to the UI Activity
*/
public BluetoothService(Context context, Handler handler) {
mAdapter = BluetoothAdapter.getDefaultAdapter();
mState = STATE_NONE;
mHandler = handler;
}
/**
* Set the current state of the connection
* @param state An integer defining the current connection state
*/
private synchronized void setState(int state) {
if (DEBUG) Log.d(TAG, "setState() " + mState + " -> " + state);
mState = state;
// Give the new state to the Handler so the UI Activity can update
mHandler.obtainMessage(PrintBluetooth.MESSAGE_STATE_CHANGE, state, -1).sendToTarget();
}
/**
* Return the current connection state. */
public synchronized int getState() {
return mState;
}
/**
* Start the service. Specifically start AcceptThread to begin a
* session in listening (server) mode. Called by the Activity onResume() */
public synchronized void start() {
if (DEBUG) 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 (DEBUG) 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 (DEBUG) 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(PrintBluetooth.MESSAGE_DEVICE_NAME);
Bundle bundle = new Bundle();
bundle.putString(PrintBluetooth.DEVICE_NAME, device.getName());
msg.setData(bundle);
mHandler.sendMessage(msg);
setState(STATE_CONNECTED);
}
/**
* Stop all threads
*/
public synchronized void stop() {
if (DEBUG) Log.d(TAG, "stop");
setState(STATE_NONE);
if (mConnectThread != null) {mConnectThread.cancel(); mConnectThread = null;}
if (mConnectedThread != null) {mConnectedThread.cancel(); mConnectedThread = null;}
if (mAcceptThread != null) {mAcceptThread.cancel(); mAcceptThread = null;}
}
/**
* 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) return;
r = mConnectedThread;
}
r.write(out);
}
/**
* 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(PrintBluetooth.MESSAGE_TOAST);
Bundle bundle = new Bundle();
bundle.putString(PrintBluetooth.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(PrintBluetooth.MESSAGE_TOAST);
Bundle bundle = new Bundle();
bundle.putString(PrintBluetooth.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;
}
@Override
public void run() {
if (DEBUG) 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 (BluetoothService.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 (DEBUG) Log.i(TAG, "END mAcceptThread");
}
public void cancel() {
if (DEBUG) 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;
}
@Override
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) {
Log.e("ERRROR :::::","INSIDE CATCH RUN");
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
BluetoothService.this.start();
return;
}
// Reset the ConnectThread because we're done
synchronized (BluetoothService.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;
}
@Override
public void run() {
Log.i(TAG, "BEGIN mConnectedThread");
int bytes;
// Keep listening to the InputStream while connected
while (true) {
try {
byte[] buffer = new byte[256];
// Read from the InputStream
bytes = mmInStream.read(buffer);
if(bytes>0)
{
// Send the obtained bytes to the UI Activity
mHandler.obtainMessage(PrintBluetooth.MESSAGE_READ, bytes, -1, buffer)
.sendToTarget();
}
else
{
Log.e(TAG, "disconnected");
connectionLost();
//add by chongqing jinou
if(mState != STATE_NONE)
{
Log.e(TAG, "disconnected");
// Start the service over to restart listening mode
BluetoothService.this.start();
}
break;
}
} catch (IOException e) {
Log.e(TAG, "disconnected", e);
connectionLost();
//add by chongqing jinou
if(mState != STATE_NONE)
{
// Start the service over to restart listening mode
BluetoothService.this.start();
}
break;
}
}
}
/**
* Write to the connected OutStream.
* @param buffer The bytes to write
*/
public void write(byte[] buffer) {
try {
mmOutStream.write(buffer);
mmOutStream.flush();//清空缓存
/* if (buffer.length > 3000) //
{
byte[] readata = new byte[1];
SPPReadTimeout(readata, 1, 5000);
}*/
Log.i("BTPWRITE", new String(buffer,"GBK"));
// Share the sent message back to the UI Activity
mHandler.obtainMessage(PrintBluetooth.MESSAGE_WRITE, -1, -1, buffer)
.sendToTarget();
} catch (IOException e) {
Log.e(TAG, "Exception during write", e);
}
}
/*
//
private boolean SPPReadTimeout(byte[] Data, int DataLen, int Timeout){
for (int i = 0; i < Timeout / 5; i++)
{
try
{
if (mmInStream.available() >= DataLen)
{
try
{
mmInStream.read(Data, 0, DataLen);
return true;
}
catch (IOException e)
{
ErrorMessage = "读取蓝牙数据失败";
return false;
}
}
}
catch (IOException e)
{
ErrorMessage = "读取蓝牙数据失败";
return false;
}
try
{
Thread.sleep(5L);
}
catch (InterruptedException e)
{
ErrorMessage = "读取蓝牙数据失败";
return false;
}
}
ErrorMessage = "蓝牙读数据超时";
return false;
}
*/
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) {
Log.e(TAG, "close() of connect socket failed", e);
}
}
}
答案 0 :(得分：0)
您应该在后台维护蓝牙连接。将蓝牙服务创建代码移动到Android服务，并使用本地绑定器访问服务对象及其方法。