运行Android 4.04的socket.connect()Galaxy Tab 2上的NullPointer Exc

Question

我似乎在socket.connect（）上遇到了这个奇怪的错误：

09-18 14:41:22.968: W/System.err(2593): java.lang.NullPointerException
09-18 14:41:22.968: W/System.err(2593):     at android.sec.enterprise.BluetoothUtils.**isSocketAllowedBySecurityPolicy**(BluetoothUtils.java:106)
09-18 14:41:22.968: W/System.err(2593):     at android.bluetooth.BluetoothSocket.connect(BluetoothSocket.java:220)
09-18 14:41:22.968: W/System.err(2593):     at com._._.android._._.bluetoothmodule.BluetoothController.connectToDevice(BluetoothController.java:136)
09-18 14:41:22.976: W/System.err(2593):     at com._._.android._._.controllermodule.ControllerModule.connectToDevice(ControllerModule.java:235)
09-18 14:41:22.976: W/System.err(2593):     at com._._.android._._.controllermodule.ControllerModule.connectToDevice(ControllerModule.java:263)
09-18 14:41:22.976: W/System.err(2593):     at com._._.android._._.service.ConnectionService.onHandleIntent(ConnectionService.java:70)
09-18 14:41:22.976: W/System.err(2593):     at android.app.IntentService$ServiceHandler.handleMessage(IntentService.java:65)
09-18 14:41:22.976: W/System.err(2593):     at android.os.Handler.dispatchMessage(Handler.java:99)
09-18 14:41:22.976: W/System.err(2593):     at android.os.Looper.loop(Looper.java:137)
09-18 14:41:22.976: W/System.err(2593):     at android.os.HandlerThread.run(HandlerThread.java:60)

是的，我在连接到套接字之前正在检查插槽是否为空。我似乎只在运行 2.0.4 的 Galaxy Tab 4 上遇到这个问题。我的代码在其他设备/安卓版本[包括JB]上运行良好。不知道这里会发生什么。下面列出的是一小块演示我如何初始化我的套接字：

Method m = bluetoothDevice.getClass().getMethod(
            "createInsecureRfcommSocket", new Class[] { int.class });
Logging.getInstance().logMessage(this.getClass().getSimpleName(), "Returned the Reflection method successfully..",Logging.LOG_ERROR);
      // get readSocket
    mreadSocket = (BluetoothSocket) m.invoke(bluetoothDevice, 1);
      assert (mreadSocket != null) : "readSocket is Null";
 if (mreadSocket != null) {
        mreadSocket.connect();
}

任何帮助将不胜感激！

Answer 1

警告：下面的代码可能不安全，使用风险自负

就我而言，我能够使用 createInsecureRfcommSocketToServiceRecord 而不是createRfcommSocketToServiceRecord进行连接，但我看到您已经在这样做了。我的代码看起来更像这样（删除了错误/异常检查）：

BluetoothDevice device;
String deviceName = ... selected or hardcoded device name. See Android HDR sample code
BluetoothDevice[] mAllBondedDevices = (BluetoothDevice[]) mBluetoothAdapter.getBondedDevices().toArray(new BluetoothDevice[0]);
for (BluetoothDevice d : mAllBondedDevices) {
  if (deviceName.equals(d.getName())) {
    device = d;
    break;
  }
}
UUID uuid = device.getUuids()[0].getUuid();
//FAILED: socket = device.createRfcommSocketToServiceRecord(uuid);
// Succeeds: Warning, INSECURE!
socket = device.createInsecureRfcommSocketToServiceRecord(uuid);
socket.connect();
this.dos = new DataOutputStream(new BufferedOutputStream(socket.getOutputStream()));
this.dis = new DataInputStream(new BufferedInputStream(socket.getInputStream()));
//etc 

请注意，虽然不安全的连接

并不完美，但在我们的情况下，不安全的连接比没有连接更可取。我发布了一个答案，以便您可以尝试替代代码。

Answer 2

我在Galaxy tab 2上遇到了同样的问题，我解决了：

        BluetoothSocket tmp = null;
        try {
            tmp = device.createRfcommSocketToServiceRecord(SPP_UUID);
            // for others devices its works with:
            // Method m = device.getClass().getMethod("createRfcommSocket", new Class[] {int.class});
            // for galaxy tab 2 with:
            Method m = device.getClass().getMethod("createInsecureRfcommSocket", new Class[] {int.class});
            tmp = (BluetoothSocket) m.invoke(device, 1);
        } catch (IOException e) {
            Log.e(TAG, "failed! error: " + e.getMessage());
        }
        socket = tmp;
        socket.connect();
        Log.i(TAG, "Client Connected!");

希望这有帮助=D