java.io.IOE：bt套接字不在监听状态【AndroidMarshmallow】

Question

我正在尝试在nexus 5（Android 6）和谷歌眼镜之间建立连接。要连接的客户端代码：

try {
    bluetoothSocket = device.createInsecureRfcommSocketToServiceRecord(
                BluetoothParametersHolder.uuids[0]);
} catch (Exception e) {
    e.printStackTrace();
}

//In a thread
bluetoothSocket.connect();

服务器端代码：

 mmServerSocket = bluetoothAdapter.listenUsingInsecureRfcommWithServiceRecord(
                BluetoothParametersHolder.NAME, BluetoothParametersHolder.uuids[0]);

//In a thread
socket = mmServerSocket.accept();

以https://github.com/vicmns/BluetoothGlass为参照。我面临的问题是，在accept()返回后，连接立即断开，并出现以下错误:

02-15 16:20:42.769 2163-2414/?e/Bt _ btif _ sock _ RFCOMM:find _ RFC _ slot _ by _ id找不到RFCOMM slot id:51 02-15 16:20:43.761 8345-8361/？w/system . err:Java . io . io异常:bt套接字不处于监听状态02-15 16:20:43.762 8345-8361/？w/system . err:at Android . bluetooth . bluetooth socket . accept(bluetooth socket . Java:453)02-15 16:20:43.763 8345-8361/？w/system . err:at Android . bluetooth . bluetooth server socket . accept(bluetooth server socket . Java:158)02-15 16:20:43.763 8345-8361/？w/system . err:at Android . bluetooth . bluetooth server socket . accept(bluetooth server socket . Java:144)02-15 16:20:43.763 8345-8361/？w/system . err:at Knowles . com . server app . handlers . bluetooth connection handler . doin background(bluetooth connection handler . Java:41)02-15 16:20:43.763 8345-8361/？w/system . err:at Knowles . com . server app . handlers . bluetooth connection handler . doin background(bluetooth connection handler . Java:16)02-15 16:20:43.763 8345-8361/？w/system . err:at Android . OS . async task $ 2 . call(async task . Java:295)02-15 16:20:43.764 8345-8361/？w/system . err:at Java . util . concurrent . future task . run(future task . Java:237)02-15 16:20:43.764 8345-8361/？w/system . err:at Android . OS . async task $ serial executor $ 1 . run(async task . Java:234)02-15 16:20:43.764 8345-8361/？w/system . err:at Java . util . concurrent . threadpoolexecutor . run worker(threadpoolexecutor . Java:1113)02-15 16:20:43.764 8345-8361/？w/system . err:at Java . util . concurrent . threadpoolexecutor $ worker . run(threadpoolexecutor . Java:588)02-15 16:20:43.782 8345-8361/？w/system . err:at Java . lang . thread . run(thread . Java:818)

我对蓝牙和眼镜很陌生。任何帮助都非常感谢。没有从现有帖子中获得太多帮助。我在这里尝试的只是从客户端（Glass）向服务器（Mobile）发送一条“你好”消息。

Answer 1

查看框架代码内部，我们可以发现以下内容:

if (mSocketState != SocketState.LISTENING)
    throw new IOException("bt socket is not in listen state");

显然，如果套接字未处于状态LISTENING，则方法accept（）抛出异常。

在大多数情况下，如果BluetoothServerSocket的实例已经关闭，就会发生这种情况。在尝试接受连接之前，请确保BluetoothServerSocket未关闭。