接受线程的IOException

Question

我的应用程序的一部分通过蓝牙连接到设备,通常工作正常但偶尔它不会连接,我得到以下错误

03-11 10:29:20.328: E/BluetoothComService(8059): accept() failed
03-11 10:29:20.328: E/BluetoothComService(8059): java.io.IOException: Operation Canceled
03-11 10:29:20.328: E/BluetoothComService(8059):    at android.bluetooth.BluetoothSocket.acceptNative(Native Method)
03-11 10:29:20.328: E/BluetoothComService(8059):    at android.bluetooth.BluetoothSocket.accept(BluetoothSocket.java:316)
03-11 10:29:20.328: E/BluetoothComService(8059):    at android.bluetooth.BluetoothServerSocket.accept(BluetoothServerSocket.java:105)
03-11 10:29:20.328: E/BluetoothComService(8059):    at android.bluetooth.BluetoothServerSocket.accept(BluetoothServerSocket.java:91)
03-11 10:29:20.328: E/BluetoothComService(8059):    at com.mypackage.name.bluetooth.BluetoothService$AcceptThread.run(BluetoothService.java:298)

这是我得到例外的那一行

socket = mmServerSocket.accept();    

这是完整的AcceptThread

private class AcceptThread extends Thread {
    // The local server socket
    private BluetoothServerSocket mmServerSocket;
    public boolean successInit = false;

    public AcceptThread() {
        closeAllConnections();

        /*
         * if(mmServerSocket != null) { try { mmServerSocket.close(); } catch
         * (IOException e) { e.printStackTrace(); } }
         */
        BluetoothServerSocket tmp = null;

        // Create a new listening server socket
        while (!successInit) {
            try {
                tmp = mAdapter
                        .listenUsingRfcommWithServiceRecord(NAME, MY_UUID);

                successInit = true;
            } catch (Exception e) {

                successInit = false;
            }
        }

        /*
         * try { tmp = mAdapter.listenUsingRfcommWithServiceRecord(NAME,
         * MY_UUID); successInit= true; } catch (IOException e) { Log.e(TAG,
         * "listen() failed", e); tmp = null; successInit = false; }
         */
        mmServerSocket = tmp;
    }

    public void run() {
        if (D)
            Log.d(TAG, "BEGIN mAcceptThread" + this);
        setName("AcceptThread");
        BluetoothSocket socket = null;

        // Listen to the server socket if we're not connected
        while (mState != STATE_CONNECTED) {
            try {
                // This is a blocking call and will only return on a
                // successful connection or an exception
                mAdapter.cancelDiscovery();

                socket = mmServerSocket.accept();
            } catch (IOException e) {
                Log.e(TAG, "accept() failed", e);
                Log.e("Error", "This isn't connecting");
                break;
            }

            // If a connection was accepted
            if (socket != null) {
                synchronized (BluetoothService.this) {
                    switch (mState) {
                    case STATE_LISTEN:
                    case STATE_CONNECTING:
                        // Situation normal. Start the connected thread.
                        connected(socket, socket.getRemoteDevice());
                        break;
                    case STATE_NONE:
                    case STATE_CONNECTED:
                        // Either not ready or already connected. Terminate new
                        // socket.
                        try {
                            socket.close();
                        } catch (IOException e) {
                            Log.e(TAG, "Could not close unwanted socket", e);
                        }
                        break;
                    }
                }
            }
        }
        if (D)
            Log.i(TAG, "END mAcceptThread");
    }

    public void cancel() {
        if (D)
            Log.d(TAG, "cancel " + this);
        try {
            mmServerSocket.close();
        } catch (IOException e) {
            Log.e(TAG, "close() of server failed", e);
        }
    }
}     

这是我在开始时调用的函数AcceptThread,希望关闭所有内容以重新启动它

public void closeAllConnections() {
    if (mmInStream != null) {
        try {mmInStream.close();}
        catch  (Exception e){Log.e(TAG, "close() of connect socket failed", e);}
    }
    if (mmOutStream != null) {
        try {mmOutStream.close();}
        catch (Exception e){Log.e(TAG, "close() of connect socket failed", e);}
    }
    if (mmSocket != null) {
        try {
            mmSocket.close();
            //mmSocket.connect();
        }
        catch (IOException e) {
            Log.e(TAG, "close() of connect socket failed", e);
        }
    }
}

我已经阅读了蓝牙文档和SO问题,但我没有发现任何对我有用的东西,这对我来说有点混乱,因为这是我第一次通过BT连接.

注意

发生这种情况时,我发现的唯一"修复"是关闭BT适配器,强制关闭程序,重启BT适配器并重启应用程序,这显然不是很好.我尝试以编程方式重新启动适配器,但我仍然无法连接.

任何人都可以看到我的BlutoothService类可能出现的问题,它位于何处AcceptThread？或者我将如何解决这个问题？谢谢!

更新

事实上,它看起来似乎有时在一个Thread连接上关闭并试图在另一个连接上重新连接.问题是,我无法弄清楚是什么原因导致它尝试单独连接Thread或如何在发生这种情况时进行修复.

我能成功重现这一点的唯一方法是,如果我的BT设备关闭,那么我关闭BT适配器.当我重新打开所有东西然后我得到异常并且无法连接.我有客户认为它是随机和定期发生的,所以我希望问题是相关的.

Answer 1

当 BluetoothServerSocket 关闭或垃圾收集时，应该发生该异常。我怀疑异常发生在线程的旧副本上。就像这样：当您创建新线程时，旧线程被取消，因此 BluetoothServerSocket 被关闭，因此正确接受失败并出现该错误。在调试器中检查这一点和/或记录在哪个线程上发生各种事件；例如，在accept之后的行上以及可能在cancel函数上设置断点，然后检查那里的线程ID——异常是否发生在前一个线程上？