间歇性连接-无法连接：java.io.IOException：读取失败，套接字可能关闭或超时，读取ret：-1

Question

我有一个简单的应用程序，可通过rfcomm协议与蓝牙服务器通信。有时我可以建立良好的连接，但经常我启动应用程序并收到以下错误。我不知道从什么原因开始寻找问题的原因，因为正如我所说，它实际上有时会起作用。

Logcat：

D/CONNECTTHREAD: Could not connect: java.io.IOException: read failed, socket might closed or timeout, read ret: -1
D/BluetoothSocket: close() this: android.bluetooth.BluetoothSocket@351854e, channel: 6, mSocketIS: android.net.LocalSocketImpl$SocketInputStream@8a7b66f, mSocketOS: android.net.LocalSocketImpl$SocketOutputStream@1d8af7cmSocket: android.net.LocalSocket@4a2b005 impl:android.net.LocalSocketImpl@3c4a85a fd:java.io.FileDescriptor@5a34a8b, mSocketState: INIT
D/BluetoothSocket: close() this: android.bluetooth.BluetoothSocket@351854e, channel: 6, mSocketIS: android.net.LocalSocketImpl$SocketInputStream@8a7b66f, mSocketOS: android.net.LocalSocketImpl$SocketOutputStream@1d8af7cmSocket: null, mSocketState: CLOSED

这是我用来连接的方法：

import android.bluetooth.BluetoothDevice
import android.bluetooth.BluetoothSocket
import android.util.Log

import java.io.IOException
import java.util.*


class ConnectThread(private val bTDevice: BluetoothDevice, uuid: UUID) : Thread() {

    private val bTSocket: BluetoothSocket?

    init {
        var tmp: BluetoothSocket? = null

        try {
            tmp = this.bTDevice.createRfcommSocketToServiceRecord(uuid)
        } catch (e: IOException) {
            Log.d("CONNECTTHREAD", "Could not start listening for RFCOMM")
        }

        bTSocket = tmp
    }


    // Get Bluetooth socket
    fun getSocket(uuid: UUID?): BluetoothSocket? {
        val bTSocket: BluetoothSocket?

        var tmp: BluetoothSocket? = null

        try {
            tmp = this.bTDevice.createRfcommSocketToServiceRecord(uuid)
        } catch (e: IOException) {
            Log.d("CONNECTTHREAD", "Could not start listening for RFCOMM")
        }

        bTSocket = tmp
        return bTSocket
    }


    // Connect to device
    fun connect(bTSocket: BluetoothSocket?): Boolean {

        try {
            bTSocket!!.connect()

            if (bTSocket.isConnected) {
                // deviceItem.connected = true
                Log.d("CONNECTTHREAD", "Connected")
            }

        } catch (e: IOException) {
            Log.d("CONNECTTHREAD", "Could not connect: " + e.toString())
            try {
                bTSocket!!.close()
            } catch (close: IOException) {
                Log.d("CONNECTTHREAD", "Could not close connection:" + e.toString())
            }
            return false

        }

        return true
    }


    // Cancel connection
    fun cancel(bTSocket: BluetoothSocket?): Boolean {
        try {
            bTSocket!!.close()

            if (!bTSocket.isConnected) {
                Log.d("CONNECTTHREAD", "Connection cancelled")
            }
        } catch (e: IOException) {
            return false
        }

        return true
    }

}