I have tried to connect two devices by using the Android Bluetooth Chat example on the Android developer site. It's only connecting from one of the devices and when I am trying to connect from the other device it's not connecting and pops up a message "Unable to connect: [device name here]"
我尝试使用Android开发者网站上的Android蓝牙聊天示例连接两台设备。它仅从其中一个设备连接,当我尝试从另一个设备连接时,它没有连接并弹出消息“无法连接:[此处的设备名称]”
I am wondering if I'm using the same code on both of the devices, why is the connection made only from one side, and being refused from the other side?
我想知道我是否在两个设备上使用相同的代码,为什么只从一方进行连接,而另一方拒绝连接?
I have 2 devices - 1 running version 2.2 and 1 running v2.3.3. My request is always being sent from my Galaxy Y running 2.3.3 to a Galaxy fit-v running Android 2.2, but not vice versa. Can any one please help me out or give me suggestions based off the code below...
我有2个设备 - 1个运行版本2.2和1个运行v2.3.3。我的请求总是从运行2.3.3的Galaxy Y发送到运行Android 2.2的Galaxy fit-v,但反之亦然。任何人都可以帮助我或根据以下代码给我建议...
@Override
public void onActivityResult(int requestCode, int resultCode, final Intent data) {
switch (requestCode) {
case REQUEST_CONNECT_DEVICE:
// When DeviceListActivity returns with a device to connect
if (resultCode == Activity.RESULT_OK) {
FaceCardList.requestConnection = true;
FaceCardList.deviceSelected = false;
address = data.getExtras().getString(DeviceListActivity.EXTRA_DEVICE_ADDRESS);
device = FaceCardList.mBluetoothAdapter.getRemoteDevice(address);
// Attempt to connect to the device
FaceCardList.mChatService.connect(device);
// Get the device MAC address
}
break;
case REQUEST_ENABLE_BT:
// When the request to enable Bluetooth returns
if (resultCode == Activity.RESULT_OK) {
// Bluetooth is now enabled, so set up a chat session
setupChat();
} else {
// User did not enable Bluetooth or an error occured
Toast.makeText(this, R.string.bt_not_enabled_leaving, Toast.LENGTH_SHORT).show();
finish();
}
}
}
and the code for my BluetoothChat service is:
我的BluetoothChat服务的代码是:
public class BluetoothChatService extends Activity {
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");
// ("fa87c0d0-afac-11de-8a39-0800200c9a66");
// Member fields
private final BluetoothAdapter mAdapter;
private final 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
/**
* 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 BluetoothChatService(Context context, Handler handler) {
mAdapter = FaceCardList.mBluetoothAdapter;
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(FaceCardList.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(FaceCardList.MESSAGE_DEVICE_NAME);
Bundle bundle = new Bundle();
bundle.putString(FaceCardList.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) {
return;
}
r = mConnectedThread;
}
// Perform the write unsynchronized
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(FaceCardList.MESSAGE_TOAST);
Bundle bundle = new Bundle();
bundle.putString(FaceCardList.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(FaceCardList.MESSAGE_TOAST);
Bundle bundle = new Bundle();
bundle.putString(FaceCardList.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);
// if(!tmp.toString().equalsIgnoreCase(null)){
//
// }
} catch (IOException e) {
//Log.e(TAG, "listen() failed", e);
}
mmServerSocket = tmp;
}
@Override
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 {
socket = mmServerSocket.accept();
} catch (IOException e1) {
// TODO Auto-generated catch block
//e1.printStackTrace();
}
// If a connection was accepted
if (socket != null) {
synchronized (BluetoothChatService.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.
//Log.e("STATE_CONNECTED: service","STATE_CONNECTED: service");
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 BluetoothSocket mmSocket= null;
private final BluetoothDevice mmDevice;
public ConnectThread(BluetoothDevice device) {
mmDevice = device;
BluetoothSocket tmp = null;
System.out.println("my uuid :-"+MY_UUID);
try {
try {
//tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
mmSocket = device.createRfcommSocketToServiceRecord(MY_UUID);
System.out.println("mm socket value :-"+mmSocket);
} catch (IOException e) {
e.printStackTrace();
System.out.println("error in connecting :-"+e.getMessage());
//Log.e(TAG, "create() failed", e);
// TODO Auto-generated catch block
//e.printStackTrace();
}
} catch (SecurityException e) {
// TODO Auto-generated catch block
//e.printStackTrace();
}
// mmSocket = tmp;
System.out.println("mm socket value as temp :-----------------");
}
@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
System.out.println("before connection");
mmSocket.connect();
System.out.println("after connection ");
} catch (Exception e) {
System.out.println("in connection failed :-"+e.getMessage());
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
try {
BluetoothChatService.this.start();
} catch (Exception e2) {
// TODO: handle exception
e2.printStackTrace();
System.out.println("in connection failed start bluetooth chat service :-"+e2.getMessage());
}
return;
}
// Reset the ConnectThread because we're done
synchronized (BluetoothChatService.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");
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
// XXX !!!
String buffer2 = new String(buffer);
buffer2= buffer2.substring(0, buffer2.length()-3)+"\n";
mHandler.obtainMessage(FaceCardList.MESSAGE_READ, bytes, -1, buffer2.getBytes()).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
// XXX !!!
String buffer2 = new String(buffer);
buffer2= buffer2.substring(0, buffer2.length()-2);
mHandler.obtainMessage(FaceCardList.MESSAGE_WRITE, -1, -1,
buffer2.getBytes()).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);
}
}
}
}
I am stuck. Why is the connection always made from the higher version to a lower version but not from the lower version to a higher one?
我被卡住了。为什么连接总是从较高版本到较低版本而不是从较低版本到较高版本?
4 个解决方案
#1
5
I have done this,and i think you get connection lost when the device discoverable change. Please do check the device discoverable in both,you can enable it by code.
我已经做到了这一点,我认为当设备可发现变化时,连接会丢失。请检查两者中可发现的设备,您可以通过代码启用它。
Intent discoverableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION,0);
startActivity(discoverableIntent);
#2
2
Saurabh, make this change please and watch it work:
Saurabh,请做出这个改变并观察它的工作原理:
if (Build.VERSION.SDK_INT < 9) { // VK: Build.Version_Codes.GINGERBREAD is not accessible yet so using raw int value
// VK: 9 is the API Level integer value for Gingerbread
try {
tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
} else {
Method m = null;
try {
m = device.getClass().getMethod("createInsecureRfcommSocketToServiceRecord", new Class[] { UUID.class });
} catch (NoSuchMethodException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
tmp = (BluetoothSocket) m.invoke(device, (UUID) MY_UUID);
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
#3
1
I also think your problem is not within your code.
我也认为你的问题不在你的代码中。
Two Years ago I have modified the BluetoothChat example application. You can find the modified project here - Bluetooth Chat and the binary here: Bluetooth Chat
两年前我修改了BluetoothChat示例应用程序。您可以在此处找到修改后的项目 - 蓝牙聊天和二进制文件:蓝牙聊天
If this works better between your two devices it might help.
如果这两个设备之间的效果更好,那可能会有所帮助。
I tested it just now on Android version 2.3.3 (Nexus One) and on Version 4.0.4 (Galaxy Nexus).
我刚刚在Android 2.3.3版(Nexus One)和版本4.0.4(Galaxy Nexus)上测试过它。
#4
1
I'm not sure if just copy the code straight away and try to run it if so, bear in mind android.app.ActionBar; require version 3.0. Also Bluetooth communication is not exactly peer to peer it's Master Slave.
我不确定是否只是立即复制代码并尝试运行它,如果是这样,请记住android.app.ActionBar;需要3.0版。此外,蓝牙通信并不完全是对等的主奴。
#1
5
I have done this,and i think you get connection lost when the device discoverable change. Please do check the device discoverable in both,you can enable it by code.
我已经做到了这一点,我认为当设备可发现变化时,连接会丢失。请检查两者中可发现的设备,您可以通过代码启用它。
Intent discoverableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION,0);
startActivity(discoverableIntent);
#2
2
Saurabh, make this change please and watch it work:
Saurabh,请做出这个改变并观察它的工作原理:
if (Build.VERSION.SDK_INT < 9) { // VK: Build.Version_Codes.GINGERBREAD is not accessible yet so using raw int value
// VK: 9 is the API Level integer value for Gingerbread
try {
tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
} else {
Method m = null;
try {
m = device.getClass().getMethod("createInsecureRfcommSocketToServiceRecord", new Class[] { UUID.class });
} catch (NoSuchMethodException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
tmp = (BluetoothSocket) m.invoke(device, (UUID) MY_UUID);
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
#3
1
I also think your problem is not within your code.
我也认为你的问题不在你的代码中。
Two Years ago I have modified the BluetoothChat example application. You can find the modified project here - Bluetooth Chat and the binary here: Bluetooth Chat
两年前我修改了BluetoothChat示例应用程序。您可以在此处找到修改后的项目 - 蓝牙聊天和二进制文件:蓝牙聊天
If this works better between your two devices it might help.
如果这两个设备之间的效果更好,那可能会有所帮助。
I tested it just now on Android version 2.3.3 (Nexus One) and on Version 4.0.4 (Galaxy Nexus).
我刚刚在Android 2.3.3版(Nexus One)和版本4.0.4(Galaxy Nexus)上测试过它。
#4
1
I'm not sure if just copy the code straight away and try to run it if so, bear in mind android.app.ActionBar; require version 3.0. Also Bluetooth communication is not exactly peer to peer it's Master Slave.
我不确定是否只是立即复制代码并尝试运行它,如果是这样,请记住android.app.ActionBar;需要3.0版。此外,蓝牙通信并不完全是对等的主奴。