BluetoothSocket Connect（）引发IOException读取失败，套接字可能已关闭

Question

因此，我正在尝试将一个Android应用程序连接到raspberry Pi，设备配对并受信任，我收到一个与此处发现的错误相同的错误：IOException:读取失败，套接字可能已关闭-Android 4.3上的蓝牙

然而，这个解决方案看起来非常混乱，我甚至不知道如何将其与我当前的代码集成。以下是我目前的代码：

 @Override
    protected void onHandleIntent(Intent intent) {
        device = (BluetoothDevice) intent.getExtras().get("device");

        if (device != null) {
            Log.v("DeviceManager", "Beginning attempts to communicate to: " + device.getName());
            try {
                BluetoothSocket socket = device.createRfcommSocketToServiceRecord(MY_UUID);
                //Throws exception here:
                socket.connect();
                outputStream = socket.getOutputStream();
                inputStream = socket.getInputStream();

                while (Utils.appIsInForeground && device != null) {
                    if (outputStream == null){
                        Log.e("DeviceManager", "Looks like the outputStream is null...");
                        if (inputStream == null){
                            Log.e("DeviceManager", "And input stream is null, are you even connected to the device?");
                        }else{
                            Log.e("DeviceManager", "Although strangely, input stream has been set.");
                        }
                    }else{
                        String myString = "This is a string!";
                        byte[] myByteArray = myString.getBytes("UTF-8");
                        outputStream.write(myByteArray, 0, myByteArray.length);
                    }
                    Thread.sleep(1000);
                }

            } catch (IOException e) {
                e.printStackTrace();
                Log.e("DeviceManager", "Can't create a socket to the bluetooth device.");
            } catch (InterruptedException e) {
                e.printStackTrace();
                Log.e("DeviceManager", "The sleep thread was interrupted.");
            } catch (NullPointerException e) {
                e.printStackTrace();
                Log.e("DeviceManager", "A null pointer exception, this is probably not good.");
            }
        }else {
            Log.e("DeviceManager", "The Device Manager has been passed a null object instead of a device.");
        }
    }

这是我得到的堆栈跟踪：

03-26 11:44:09.525 7916-8048/com.app.name W/System.err: java.io.IOException: read failed, socket might closed or timeout, read ret: -1
03-26 11:44:09.526 7916-8048/com.app.name W/System.err:     at android.bluetooth.BluetoothSocket.readAll(BluetoothSocket.java:685)
03-26 11:44:09.527 7916-8048/com.app.name W/System.err:     at android.bluetooth.BluetoothSocket.readInt(BluetoothSocket.java:697)
03-26 11:44:09.527 7916-8048/com.app.name W/System.err:     at android.bluetooth.BluetoothSocket.connect(BluetoothSocket.java:374)
03-26 11:44:09.527 7916-8048/com.app.name W/System.err:     at com.app.name.service.DeviceManager.onHandleIntent(DeviceManager.java:60)
03-26 11:44:09.527 7916-8048/com.app.name W/System.err:     at android.app.IntentService$ServiceHandler.handleMessage(IntentService.java:67)
03-26 11:44:09.528 7916-8048/com.app.name W/System.err:     at android.os.Handler.dispatchMessage(Handler.java:102)
03-26 11:44:09.528 7916-8048/com.app.name W/System.err:     at android.os.Looper.loop(Looper.java:154)
03-26 11:44:09.528 7916-8048/com.app.name W/System.err:     at android.os.HandlerThread.run(HandlerThread.java:61)
03-26 11:44:09.528 7916-8048/com.app.name E/DeviceManager: Can't create a socket to the bluetooth device.

奇怪的是，我的Raspberry Pi在BluetoothCtl上显示，手机已连接，但随后立即断开连接。

Answer 1

只为查询Raspberry板上的SDP数据库而创建连接。

1） 检查树莓一侧的SDP是否真的包含请求的MY_UUID记录

2）这不是很明显，如果覆盆子板是结合与您的Android。这是必需的，因为您在发布的代码中创建了一个安全套接字。

• 您可以尝试不需要绑定设备的不安全版本：CreateUnsecurerCommsocketToServiceRecord