Android滞后/不稳定的蓝牙连接

Question

我在使用不安全的RFCOMM连接连接WML-C46 AH蓝牙芯片时遇到问题。我写了一个Android应用程序，里面只有相关的代码，可以告诉你我的问题。

应用程序

这个应用只有一个按钮。如果单击此按钮，蓝牙设备发现将启动。在发现完成后，应用程序将连接到蓝牙设备（我只使用一个蓝牙设备进行测试，所以它找不到任何其他设备）。然后，它打开一个输入流来读取该设备的数据。如果连接中断（引发ioexception）或再次单击按钮，则连接将关闭（关闭所有线程、套接字和流）。如果再次单击按钮，将启动新的设备发现，依此类推。。。

问题所在

连接不正常。数据输入流似乎有点滞后，有时连接中断，没有任何可观察到的原因（IOExc0019：软件导致连接中止或IOExc0019：重试）。这几乎是Android蓝牙聊天示例的简化版本，它使用设备发现而不是配对设备和一个活动。

密码

public class MainActivity extends Activity implements View.OnClickListener {

    BluetoothDevice btDevice;
    BluetoothSocket btSocket;
    InputStream inStream;
    OutputStream outStream;
    Object lock = new Object();
    boolean connected = false;
    boolean canceled = false;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button btn = (Button) findViewById(R.id.button1);
        btn.setOnClickListener(this);

        IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
        getApplicationContext().registerReceiver(btReceiver, filter);
        filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
        getApplicationContext().registerReceiver(btReceiver, filter);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public void onClick(View arg0) {
        if (!connected) {
            connected = true;
            canceled = false;

            new Thread(new Runnable() {
                @Override
                public void run() {
                    BluetoothAdapter btAdapter = BluetoothAdapter
                            .getDefaultAdapter();

                    try {
                        if (btAdapter.isDiscovering())
                            btAdapter.cancelDiscovery();
                        btAdapter.startDiscovery();

                        // block until device discovery has finished
                        synchronized (lock) {
                            try {
                                lock.wait();
                            } catch (InterruptedException e) {
                                Log.d("EXCEPTION", "", e);
                            }
                        }

                        btSocket = btDevice.createInsecureRfcommSocketToServiceRecord(UUID
                                .fromString("00001101-0000-1000-8000-00805F9B34FB"));
                        btSocket.connect();

                        inStream = btSocket.getInputStream();
                        outStream = btSocket.getOutputStream();

                        new Thread(new Runnable() {
                            @Override
                            public void run() {
                                while (!canceled) {
                                    try {
                                        int in;
                                        while ((in = inStream.read()) != -1) {
                                            Log.d("Received new byte: ", in
                                                    + "");
                                        }
                                    } catch (IOException e) {
                                        Log.d("EXCEPTION IN LISTENER", "", e);
                                        disconnect();
                                    }
                                }
                            }
                        }).start();
                    } catch (IOException e) {
                        Log.d("", "", e);
                    }
                }
            }).start();
        } else {
            disconnect();
        }
    }

    private void disconnect() {
        connected = false;
        canceled = true;

        try {
            btSocket.close();
        } catch (Exception e) {
            Log.d("EXCEPTION DISCONNECTING", "", e);
        }
        try {
            inStream.close();
        } catch (Exception e) {
            Log.d("EXCEPTION DISCONNECTING", "", e);
        }
        try {
            outStream.close();
        } catch (Exception e) {
            Log.d("EXCEPTION DISCONNECTING", "", e);
        }

        btDevice = null;
        btSocket = null;
        inStream = null;
        outStream = null;
    }

    private final BroadcastReceiver btReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            try {
                if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                    btDevice = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                } else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
                    synchronized (lock) {
                        lock.notifyAll();
                    }
                }
            } catch (Exception e) {
                Log.d(this.getClass().getName(), "", e);
            }
        }
    };
}

我只使用阻塞方法或自己进行阻塞。因此，建立联系的程序性很强。当我修改android示例时，我可能已经丢失了它的连接流，但我找不到问题所在。

输出

建立连接：

01-16 16:52:46.234: V/BluetoothSocket.cpp(6961): initSocketNative
01-16 16:52:46.234: V/BluetoothSocket.cpp(6961): ...fd 47 created (RFCOMM, lm = 0)
01-16 16:52:46.234: V/BluetoothSocket.cpp(6961): initSocketFromFdNative
01-16 16:52:46.257: D/BluetoothUtils(6961): isSocketAllowedBySecurityPolicy start : device null
01-16 16:52:47.171: V/BluetoothSocket.cpp(6961): connectNative
01-16 16:52:47.570: V/BluetoothSocket.cpp(6961): ...connect(47, RFCOMM) = 0 (errno 115)

连接中断：

01-16 16:53:38.539: D/EXCEPTION IN LISTENER(6961): java.io.IOException: Software caused connection abort
01-16 16:53:38.539: D/EXCEPTION IN LISTENER(6961):  at android.bluetooth.BluetoothSocket.readNative(Native Method)
01-16 16:53:38.539: D/EXCEPTION IN LISTENER(6961):  at android.bluetooth.BluetoothSocket.read(BluetoothSocket.java:388)
01-16 16:53:38.539: D/EXCEPTION IN LISTENER(6961):  at android.bluetooth.BluetoothInputStream.read(BluetoothInputStream.java:60)
01-16 16:53:38.539: D/EXCEPTION IN LISTENER(6961):  at com.example.bttest.MainActivity$2$1.run(MainActivity.java:100)
01-16 16:53:38.539: D/EXCEPTION IN LISTENER(6961):  at java.lang.Thread.run(Thread.java:856)

谢谢

Answer 1

找到问题了。蓝牙设备没有按预期工作，几秒钟后关闭了连接。然而，代码工作正常。