我试图写一个code，只有连接到我（现在）只配对设备上我的Nexus 7运行Android 4.4奇巧。无论我有多少东西都试过了，我仍然得到这个错误。这是最后的code我都试过了，这似乎是尽我见过的人报告为成功。

任何人都可以点我什么，我做错了吗？

  BluetoothManager bluetoothManager =            （BluetoothManager）getSystemService（Context.BLUETOOTH_SERVICE）;BluetoothAdapter适配器= bluetoothManager.getAdapter（）; // BluetoothAdapter.getDefaultAdapter（）;如果（！adapter.isEnabled（））{    意图enableBtIntent =新意图（BluetoothAdapter.ACTION_REQUEST_ENABLE）;    startActivityForResult（enableBtIntent，REQUEST_ENABLE_BT）;}BluetoothDevice类BT = adapter.getBondedDevices（）迭代器的next（）（）;BluetoothDevice类实际= adapter.getRemoteDevice（bt.getAddress（））;字符串str =;为（BluetoothDevice类BD：adapter.getBondedDevices（））{    STR + = bd.getName（）+\\ n;}STR + =实际;textView.setText（STR）;的BluetoothSocket插座= actual.createInsecureRfcommSocketToServiceRecord（MY_UUID）;adapter.cancelDiscovery（）;socket.connect（）;为PrintWriter了=的新PrintWriter（socket.getOutputStream（））;的out.print（消息）;了out.flush（）; 

解决方案

我有完全相同的错误（IOException异常读取失败插座有可能关闭或超时）与ELM327 OBD蓝牙适配器。

  UUID MY_UUID = UUID.fromString（00001101-0000-1000-8000-00805F9B34FB）;btDevice = btAdapter.getRemoteDevice（btDeviceAddress）;btAdapter.cancelDiscovery（）;btSocket = btDevice.createRfcommSocketToServiceRecord（MY_UUID）;btSocket.connect（）; 

该ELM327将允许第一个连接并发送/接收正确的，但只有一次。随后，其随后所有的连接将失败，并抛出IOException。为了得到它重新工作，我不得不从OS取消配对的ELM327，然后我能够连接 - 只有一次！如此循环往复......

在上面的描述后，问题得到了解决 - 创建一个不安全插座

  btSocket = btDevice.createInsecureRfcommSocketToServiceRecord（MY_UUID）; 

I'm trying to write a code that only connect to my (for now) only paired device on my Nexus 7 running Android 4.4 KitKat. No matter how many thing I have tried, I still get this error. This is the last code I have tried, which seems to be doing everything I've seen people report as successful.

Can anybody point me to what I'm doing wrong?

BluetoothManager bluetoothManager =
            (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
BluetoothAdapter adapter = bluetoothManager.getAdapter();//BluetoothAdapter.getDefaultAdapter();
if (!adapter.isEnabled()) {
    Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
    startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}
BluetoothDevice bt = adapter.getBondedDevices().iterator().next();
BluetoothDevice actual = adapter.getRemoteDevice(bt.getAddress());
String str = "";
for(BluetoothDevice bd : adapter.getBondedDevices()) {
    str += bd.getName() + "\n";
}
str+= actual;

textView.setText(str);
BluetoothSocket socket = actual.createInsecureRfcommSocketToServiceRecord(MY_UUID);
adapter.cancelDiscovery();
socket.connect();
PrintWriter out = new PrintWriter(socket.getOutputStream());
out.print(message);
out.flush();

I had the exactly same error (IOException read failed socket might closed or timeout) with an ELM327 OBD bluetooth adapter.

UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
btDevice = btAdapter.getRemoteDevice(btDeviceAddress);
btAdapter.cancelDiscovery();
btSocket = btDevice.createRfcommSocketToServiceRecord(MY_UUID);
btSocket.connect();

The ELM327 would allow the first connection and send/receive correctly, but only once. Then, all later connections would fail with the IOException. To get it working again, I had to unpair the ELM327 from the OS, and then I'd be able to connect - just once! And the cycle repeats ...

The problem was solved as described in the post above - create an INSECURE socket.

btSocket = btDevice.createInsecureRfcommSocketToServiceRecord(MY_UUID);