嵌入式设备的Android 4.0+蓝牙连接错误:“权限被拒绝”

时间:2012-11-22 22:03:15

标签: android bluetooth embedded

我有以下设置:

Android设备使用“客户端”套接字连接到远程嵌入式设备,Android应用程序使用以下代码段连接到嵌入式设备。

在嵌入式设备上使用MindTree BT堆栈,根据Android应用程序熟悉的设备中的某些属性准备服务器串行套接字,嵌入式设备上定义的连接不受保护!!

两个应用程序的组合适用于:

  • 2部LG手机不同型号(版本代码< 10 使用“普通方式”
  • 2 HTC的不同型号(版本代码< 10 使用“替代方法”
  • Pantech Tablet(版本代码< 13 使用“替代方法”

今天,我尝试过三星S3,摩托罗拉MB886和Nexus 7的应用...... 调用 socket.connect()时,所有这些都导致“权限被拒绝”...(我在清单中拥有适当的权限,否则它将无法在其他设备上运行。)

我测试过的所有新设备都是版本代码> 4.0,所以我想知道:

有人知道API的任何变化吗? 也许Android 4.0+强制安全?

似乎错误发生在Bonding状态,因为我可以在嵌入式程序日志中看到......

任何见解?

代码:

public final synchronized int connectToDevice(int connectingMethod)
        throws BluetoohConnectionException {
    if (socket != null)
        throw new BadImplementationException("Error socket is not null!!");
    connecting = true;
    logInfo("+---+ Connecting to device...");

    try {
        lastException = null;
        lastPacket = null;
        if (connectingMethod == BluetoothModule.BT_StandardConnection
                || connectingMethod == BluetoothModule.BT_ConnectionTBD)
            try {

                socket = fetchBT_Socket_Normal();
                connectToSocket(socket);
                listenForIncomingSPP_Packets();
                onConnetionEstablished();
                return BluetoothModule.BT_StandardConnection;
            } catch (BluetoohConnectionException e) {
                socket = null;
                if (connectingMethod == BluetoothModule.BT_StandardConnection) {
                    throw e;
                }
                logWarning("Error creating socket!", e);
            }
        if (connectingMethod == BluetoothModule.BT_ReflectiveConnection
                || connectingMethod == BluetoothModule.BT_ConnectionTBD)
            try {
                socket = fetchBT_Socket_Reflection(1);
                connectToSocket(socket);
                listenForIncomingSPP_Packets();
                onConnetionEstablished();
                return BluetoothModule.BT_ReflectiveConnection;
            } catch (BluetoohConnectionException e) {
                socket = null;
                if (connectingMethod == BluetoothModule.BT_ReflectiveConnection) {
                    throw e;
                }
                logWarning("Error creating socket!", e);
            }
        throw new BluetoohConnectionException("Error creating RFcomm socket for BT Device:" + this
                + "\n BAD connectingMethod==" + connectingMethod);
    } finally {
        connecting = false;
    }
}

protected void onConnetionEstablished() {
    logInfo("+---+ Connection established");
}

private synchronized void listenForIncomingSPP_Packets() {
    if (socketListeningThread != null)
        throw new BadImplementationException("Already lisening on Socket for BT Device" + this);
    logInfo("+---+ Listening for incoming packets");
    socketListeningThread = new Thread(socketListener, "Packet Listener - " + bluetoothDevice.getName());
    socketListeningThread.start();
}

private BluetoothSocket fetchBT_Socket_Normal()
        throws BluetoohConnectionException {
    try {
        logInfo("+---+ Fetching BT RFcomm Socket standard for UUID: " + uuid + "...");
        return bluetoothDevice.createRfcommSocketToServiceRecord(UUID.fromString(uuid));
    } catch (Exception e) {
        throw new BluetoohConnectionException("Error Fetching BT RFcomm Socket!", e);
    }
}

private BluetoothSocket fetchBT_Socket_Reflection(int connectionIndex)
        throws BluetoohConnectionException {
    Method m;
    try {
        logInfo("+---+ Fetching BT RFcomm Socket workaround index " + connectionIndex + "...");
        m = bluetoothDevice.getClass().getMethod("createRfcommSocket", new Class[]{int.class});
        return (BluetoothSocket) m.invoke(bluetoothDevice, connectionIndex);
    } catch (Exception e) {
        throw new BluetoohConnectionException("Error Fetching BT RFcomm Socket!", e);
    }
}

private void connectToSocket(BluetoothSocket socket)
        throws BluetoohConnectionException {
    try {
        logInfo("+---+ Connecting to socket...");
        socket.connect();
        logInfo("+---+ Connected to socket");
    } catch (IOException e) {
        try {
            socket.close();
        } catch (IOException e1) {
            logError("Error while closing socket", e1);
        } finally {
            socket = null;
        }
        throw new BluetoohConnectionException("Error connecting to socket with Device" + this, e);
    }
}

1 个答案:

答案 0 :(得分:0)

经过很长时间的调查,我发现了一个错误的原因......在某些Android设备上,未启用/允许自动蓝牙对等。

所以,显然除了两种连接方法外,还有两种蓝牙适配器启用方法,一种是要求系统打开适配器,另一种是调用BluetoothAdapter.enable( )方法,可以无声地启用蓝牙。

第一种方法,弹出确认对话框,要求用户互动,而另一种方法没有,并且在未显示蓝牙启用确认对话框的同时,也未显示对等确认,这会导致连接错误。

使用第一个适配器启用方法解决了大多数设备上的问题,例如Nexus 7,Samsung S3和其他一些设备,但在某些设备上仍存在问题,我不确定为什么,但这要好得多,因为现在许多设备正在使用新的实现。