Question

我正在为SDK 10（2.3.3）编译：

android:minSdkVersion="10"
android:targetSdkVersion="16"

我正在测试两款索尼爱立信智能手机。其中一个有Android 2.3.7，另一个有4.0.1。

我正在使用listenUsingInsecureRfcommWithServiceRecord在蓝牙上打开一个新的服务器套接字并监听连接。

如果成功接受连接，那么一切正常。我甚至可以尝试取消服务器套接字，但这似乎并没有打扰刚刚创建的连接套接字。

但是当我想在行bluetoothServerSocket.close();执行完毕后接受任何连接之前取消服务器套接字时，整个活动就会关闭并且进程终止。此外，这是我可以处理的不是常规异常。

实际上甚至logcat本身都会退出!!我必须再次快速执行它以获取您可以在下面看到的错误：

Zygote  D  Process 25471 terminated by signal (11)
  295         InputDispatcher  W  channel '2c2e20a8 com.pligor.test/activities.MainActivity (server)' ~ Consumer closed input channel or an error occurred.  events=0x8
  295         InputDispatcher  E  channel '2c2e20a8 com.pligor.test/activities.MainActivity (server)' ~ Channel is unrecoverably broken and will be disposed!
  295                dalvikvm  D  GC_FOR_ALLOC freed 1299K, 21% free 13252K/16583K, paused 93ms
  295         InputDispatcher  W  Attempted to unregister already unregistered input channel '2c2e20a8 com.pligor.test/activities.MainActivity (server)'
  295        BluetoothService  D  Tracked app 25471 diedType:10
  295        BluetoothService  D  Removing service record 10009 for pid 25471
  132          SurfaceFlinger  D  Release buffer at 0x61c08
  295           WindowManager  I  WINDOW DIED Window{2c2e20a8 com.pligor.test/activities.MainActivity paused=false}
  295         ActivityManager  I  Process com.pligor.test (pid 25471) has died.
  295         ActivityManager  W  Force removing ActivityRecord{2c021800 com.pligor.test/activities.MainActivity}: app died, no saved state
  295           WindowManager  W  Failed looking up window
  295           WindowManager  W  java.lang.IllegalArgumentException: Requested window android.os.BinderProxy@2bf3e798 does not exist
  295           WindowManager  W    at com.android.server.wm.WindowManagerService.windowForClientLocked(WindowManagerService.java:7165)
  295           WindowManager  W    at com.android.server.wm.WindowManagerService.windowForClientLocked(WindowManagerService.java:7156)
  295           WindowManager  W    at com.android.server.wm.WindowState$DeathRecipient.binderDied(WindowState.java:1545)
  295           WindowManager  W    at android.os.BinderProxy.sendDeathNotice(Binder.java:417)
  295           WindowManager  W    at dalvik.system.NativeStart.run(Native Method)
  295           WindowManager  I  WIN DEATH: null
  295      BluetoothEventLoop  D  Property Changed: UUIDs : 11
  295    hAdapterStateMachine  D  BluetoothOn process message: 51
  295     InputManagerService  W  Got RemoteException sending setActive(false) notification to pid 25471 uid 10040

注意：由信号（11）终止的过程意味着分段错误（http://en.wikipedia.org/wiki/SIGSEGV）。

修改

我使用以下代码（Scala）创建 Bluetooth 服务器套接字：

private val bluetoothServerSocket: BluetoothServerSocket = try {
    bluetoothAdapter.listenUsingInsecureRfcommWithServiceRecord(MY_SERVICE_NAME_INSE‌CURE, MY_UUID_INSECURE); 
} 
catch { 
    case e: IOException => throw new ServerSocketException; 
}

我使用此代码关闭蓝牙套接字：

try { 
    isCancelled = true; 
    bluetoothServerSocket.close(); 
} catch { 
    case e: IOException => throw new NotClosedException; 
}

Answer 1

我遇到了类似的问题，问题的根本原因是多次在套接字上调用close。为了解决这个问题，我将蓝牙套接字包装在一个特殊的类中，以防止关闭方法被多次调用。

请注意，关闭蓝牙套接字创建的流能够在套接字上调用close。以下解决了这个问题。

public class CloseOnceBluetoothSocket 
{
private final BluetoothSocket mSocket;
private boolean mIsClosed;

public CloseOnceBluetoothSocket(BluetoothSocket socket)
{
    this.mSocket = socket;
}

public void connect() throws IOException
{
    mSocket.connect();
}

public InputStream getInputStream() throws IOException
{
    return new FilterInputStream(mSocket.getInputStream()) {
        @Override
        public void close() throws IOException
        {
            CloseOnceBluetoothSocket.this.close();
        }
    };
}

public OutputStream getOutputStream() throws IOException
{
    return new FilterOutputStream(mSocket.getOutputStream()) {
        @Override
        public void close() throws IOException
        {
            CloseOnceBluetoothSocket.this.close();
        }
    };
}

public void close() throws IOException
{
    synchronized (mSocket) {
        if (!mIsClosed) {
            mSocket.close();
            mIsClosed = true;
        }
    }
}
}

Answer 2

如果关闭套接字会造成很大的损害，那么为什么不创建一个布尔标志，当用户连接时设置为true，当用户断开连接时设置为false;然后只有在用户之前连接时才调用close。

Answer 3

我想我找到了解决这个问题的方法。 “我认为”是因为尚未在许多设备上测试过。

下面的代码是Scala

对于解决方法，我利用了超时方法 accept（int），它有一个超时

所以我们有一个变量用于你在下面看到的无限循环的状态

private var toContinue = true;

我们只是在一个循环中重复接受

while (toContinue) {
  try {
    //this is a blocking call and will only return on a successful connection or an exception, or on timeout
    val socket = bluetoothServerSocket.accept(10000); //msec

    connectionAccepted(socket);
  } catch {
    case e: IOException => {
      Logger("accepting timed out");
    }
  }
}

所以现在不是调用bluetoothServerSocket.close()而是将变量设置为false

def cancel() {
    toContinue = false;
}

实际代码有点复杂，因为你需要一个回调函数来在while循环退出时执行某些操作，但主要问题已解决，如上所示

在接受之前取消蓝牙服务器套接字时，整个过程终止。为什么？

3 个答案: