How to connect a bluetooth adapter with Object Push Protocol?

I saw in Android 2.1 highlight it said new platform support: "Bluetooth 2.1, New BT profiles: Object Push Profile (OPP) and Phone Book Access Profile (PBAP)". Now I have bluetooth adpater with OPP support. I can search and pair with it. But how can I get the txt file it send to me. There is no API for this function. I'm using the BluetoothChat sample code like structure as below. But the code is block in "bytes = mmInStream.read(buffer);". And nothing happens. Why? Nothing received?

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;
    }

    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(BluetoothChat.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(BluetoothChat.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);
        }
   开发者_如何学JAVA }
}

As far as I know, OPP and PBAP features are provided for developers by Android API.

What they did was implement these profiles as applications, and ship it with the platform. You can see in your device that there are OPP and PBAP services running, so they will accept and handle the external connections, not your app.

The source code for these apps I mentioned are available here:
https://android.googlesource.com/platform/packages/apps/Bluetooth