android.bluetooth.BluetoothSocket 无法连接

Question

我已经尝试了其他评论中的所有建议但无济于事，我希望有人可以帮助我。我已经为这个问题苦苦挣扎了三天了。我非常确定我的 UUID 是正确的，并且我知道蓝牙访问已在清单中启用。

我正在尝试将我的 Android 应用程序连接到在 Fedora 中运行的 python 服务器。它间歇性地起作用，现在根本不起作用。我收到的 android 异常通常是这样的。这些异常是在 btSocket.connect(); 时抛出的。在下面附加的代码中执行。

12-09 05:08:42.331: ERROR/BluetoothService(676): java.io.IOException: Service discovery failed

或者

12-09 05:27:00.757: ERROR/BluetoothService(729): java.io.IOException: Service discovery failed

这是我的 Android 蓝牙类，应该可以处理所有事情。当主应用程序类收到套接字已连接的消息时启动该线程。我的蓝牙课程基于 http://www.anddev.org/viewtopic.php ？p=35487#35487。

package spin.halo;

import java.io.*;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.UUID;

import android.bluetooth.*;
import android.os.Handler;
import android.util.Log;

public class BluetoothService extends Thread{

    private static final String TAG = "BluetoothService";
    private static final boolean D = true;
    private BluetoothAdapter mBluetoothAdapter = null;
    private BluetoothSocket btSocket = null;
    private OutputStream outStream = null;
    private InputStream inStream = null;
    private static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");

    private static String address;

    private Handler appHandler;

    public BluetoothService(Handler h) {
        if (D)
            Log.e(TAG, "+++ ON CREATE +++");

        appHandler = h;

        mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        if (mBluetoothAdapter == null) {
            Log.e(TAG, "NO BT ADAPTER!");
            return;
        }

        if (!mBluetoothAdapter.isEnabled()) {
            Log.e(TAG, "Bluetooth is not enabled!");
            return;
        }

        if (D)
            Log.e(TAG, "+++ DONE IN ON CREATE, GOT LOCAL BT ADAPTER +++");
    }

    public void connectToServer() {
        connectToServer("60:33:4B:25:0D:37");
    }

    public void connectToServer(String serverMacAddress) {

        address = serverMacAddress;
        //
        if (D) {
            Log.e(TAG, "+ ABOUT TO ATTEMPT CLIENT CONNECT +");
        }

        BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
        Log.v(TAG, "REMOTE DEVICE: " + device.toString());

        try {
            btSocket = device.createRfcommSocketToServiceRecord(MY_UUID);
            Log.v(TAG, "SOCKET: " + btSocket.toString());
        } catch (Exception e) {
            Log.e(TAG, "ON RESUME: Socket creation failed.", e);
        }

        /* Discovery may be going on, e.g., if you're running a
         'scan for devices' search from your handset's Bluetooth
         settings, so we call cancelDiscovery(). It doesn't hurt
         to call it, but it might hurt not to... discovery is a
         heavyweight process; you don't want it in progress when
         a connection attempt is made.*/
        mBluetoothAdapter.cancelDiscovery();

        // Blocking connect, for a simple client nothing else can
        // happen until a successful connection is made, so we
        // don't care if it blocks.

        try {
            btSocket.connect();
            Log.e(TAG, "ON RESUME: BT connection established, data transfer link open.");
            appHandler.sendMessage(appHandler.obtainMessage(ValidationApp.BT_CONNECTION_MADE, ""));
        } catch (IOException e) {
            try {
                Log.e(TAG, "ON RESUME: Could not connect", e);
                btSocket.close();
            } catch (IOException e2) {
                Log.e(TAG, "ON RESUME: Unable to close socket during connection failure", e2);
            }
        }

        // Create output stream
        try {
            outStream = btSocket.getOutputStream();
        } catch (IOException e) {
            Log.e(TAG, "ON RESUME: Output stream creation failed.", e);
        }

        // Create input stream
        try {
            inStream = btSocket.getInputStream();
        } catch (IOException e) {
            Log.e(TAG, "Input stream creation failed.", e);
        }
    }

    public void write(String message) {
        if(message.length() > 0) {
            byte[] msgBuffer = message.getBytes();
            try {
                outStream.write(msgBuffer);
            } catch (IOException e) {
                Log.e(TAG, "ON RESUME: Exception during write.", e);
            }
        }
    }

    public void run() {
        LineNumberReader mLineReader = new LineNumberReader(new InputStreamReader(inStream));
        while(true) {
            try {
                String message = mLineReader.readLine();

                if(D) {Log.v(TAG, "Bluetooth says: " + message);}
                Log.v(TAG, appHandler.obtainMessage(ValidationApp.BT_MESSAGE, message).toString());
                appHandler.sendMessage(appHandler.obtainMessage(ValidationApp.BT_MESSAGE, message));
            } catch (IOException e) {
                Log.e(TAG, "startListen: ", e);
            }
        }
    }
}

我的 python 代码的关键部分如下。我对这段代码很有信心。

# pybluez library
import bluetooth

server_socket = bluetooth.BluetoothSocket( bluetooth.RFCOMM )
client_sockets = []

server_socket.bind(("",bluetooth.PORT_ANY))
port = server_socket.getsockname()[1]
uuid = "00001101-0000-1000-8000-00805F9B34FB"

print "Listening for devices..."

# advertise service
server_socket.listen(1)
bluetooth.advertise_service( server_socket, "Validation Host",
    service_id = uuid,
    service_classes = [ uuid, bluetooth.SERIAL_PORT_CLASS ],
    profiles = [ bluetooth.SERIAL_PORT_PROFILE ],
)

# accept incoming connections
client_sock, client_info = server_socket.accept()
client_sockets.append(client_sock)
print "Accepted Connection from ", client_info

感谢您的浏览。

Answer 1

您的代码看起来总体不错，我假设您只是从一些示例中复制并粘贴它。

部分 Android 手机（例如 HTCdesire）存在 bug，导致 device.createRfcommSocketToServiceRecord 方法失​​败。我建议采用以下方法：

1）尝试使用提供的 pythong 脚本在两台 Linux 计算机之间聊天
http://www.radekdostal.com（你知道在哪里）
这样您就可以验证您的 Linux 设置是否正常工作。

2) 尝试启动从计算机到 Android 的连接（使用 android-bluetooth-chat-c​​lient-python） 请注意，默认的 BluetoothChat 演示只能在第一次尝试时接受连接。

3) 尝试从 Android 手机连接到 Linux 计算机，但使用以下代码手动指定 RFCOMM 通道号

// BUGBUG: Following code is not properly implemented on HTC DESIRE
// mSocket =                  device.createRfcommSocketToServiceRecord(UUID.fromString("6a462dc0-703a-4bf3-a80e-a473a6332c64"));
// WORKAROUND: Connecting directly to RFCOMM channel 1
Method m = device.getClass().getMethod("createRfcommSocket", new Class[] { int.class });
mSocket = (BluetoothSocket) m.invoke(device, Integer.valueOf(1)); // 1==RFCOMM channel code 

您需要使用以下代码找出您的 RFCOMM 通道号

# sdptool browse local