无法在Android平台上使用蓝牙套接字的InputStream创建ObjectInputStream

Question

我正在为 Android 手机编写一款多人游戏。通过蓝牙进行通信。我已成功使用输入/输出流将字节从一部手机发送到另一部手机。因为我需要能够传输对象，所以我需要对象流。但是，当我尝试使用我的流创建对象流时，我的程序会挂起指令。

public class ConnectedThread extends Thread {
private static final String TAG = "Connected Thread";
private final BluetoothSocket mmSocket;
private final InputStream mmInStream;
private final OutputStream mmOutStream;
private Handler mHandler;
private ObjectInputStream ois;
private ObjectOutputStream oos;

public ConnectedThread(BluetoothSocket socket,Handler h) {
    mmSocket = socket;
    mHandler = h;

    InputStream tmpIn = null;
    OutputStream tmpOut = null;

    // Get the input and output streams, using temp objects because
    // member streams are final
    try {
        tmpIn = socket.getInputStream();
        tmpOut = socket.getOutputStream();
    } catch (IOException e) { }

    mmInStream = tmpIn;
    mmOutStream = tmpOut;
    Log.d(TAG,"attempting to create OIS");

    try {
    ois = new ObjectInputStream(mmInStream);

// 指令 new ObjectInputStream(mmInStream) 永远不会完成执行。它似乎没有抛出错误，因为我会捕获它。它只是挂在这条指令上。该行下面的代码都不会被执行。

    } catch (Exception e) {

        Log.e(TAG,"Error");
        Log.d(TAG,e.getMessage());
        e.printStackTrace();
    } 

    Log.d(TAG,"attempting to create OOS");
    try {
        oos = new ObjectOutputStream(mmOutStream);
    } catch (IOException e) {
        Log.e(TAG,"IO exception for Output Stream, I have no idea what caused this");
        Log.d(TAG,e.getMessage());
    }

}

public void run() {.....}

我做错了什么？

Answer 1

只需在构造 ObjectInputStream 之前在两端构造 ObjectOutputStream 和 flush() 即可。不必编写您自己的任何数据。

Answer 2

正如 EJP 所建议的......

        ObjectOutputStream oos = new ObjectOutputStream(socket.getOutputStream());
        oos.flush();
        ObjectInputStream is = new ObjectInputStream(socket.getInputStream());

Answer 3

好吧，我想我知道我做错了什么。对象流更复杂，看来 ObjectInputStream 构造函数在创建流之前需要处理数据。我通过

1. 创建 OOS 解决了这个问题。
2. 在单独的线程中启动 OIS 的构造函数。
3. 将一些数据写入 OOS 并刷新它。
4. 等待 OIS 初始化，然后再读取。

这就是我现在使用的（请注意，我还添加了一个缓冲区）：

public ConnectedThread(BluetoothSocket socket,Handler h) {
    mmSocket = socket;
    mHandler = h;

    InputStream tmpIn = null;
    OutputStream tmpOut = null;

    // Get the input and output streams, using temp objects because
    // member streams are final
    try {
        tmpIn = socket.getInputStream();
        tmpOut = socket.getOutputStream();
    } catch (Exception e) { 
        Log.d(TAG,"Error in getting Input Streams");
        Log.w(TAG,e);

    }

    mmInStream = tmpIn;
    mmOutStream = tmpOut;


    Log.d(TAG,"The socket is: " + mmSocket);
    Log.d(TAG,"The streams are: " + mmInStream + mmOutStream);
    Log.d(TAG,"attempting to create BufStreams");

    final BufferedOutputStream bufo = new BufferedOutputStream(mmOutStream);
    final BufferedInputStream bufi = new BufferedInputStream(mmInStream);

    Log.d(TAG,"attempting to create OOS");

    try {
        oos = new ObjectOutputStream(bufo);



    } catch (StreamCorruptedException e) {
        Log.d(TAG,"Caught Corrupted Stream Exception");
        Log.w(TAG,e);

    } catch (IOException e) {
        Log.d(TAG,"Caught IOException");
        Log.w(TAG,e);
    }

    Log.d(TAG,"done OOS");

    if(oos==null)
      {
           Log.d(TAG,"oos is null!!!!");
      }


    Thread s = new Thread(){
        public void run(){
            Log.d(TAG,"attempting to create OIS");
            try {
                ois = new ObjectInputStream(bufi);
            } catch (StreamCorruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            Log.d(TAG,"completed OIS");
            if(ois == null)
            {
                Log.d(TAG,"OIS is null");
            }
        }




    };
    s.start();
    try {
        Log.d(TAG,"writing and flushing 1");
        oos.write(1);
        oos.flush();
    } catch (IOException e1) {
        Log.d(TAG,"CaugtIOexception");
        Log.w(TAG,e1);
    }
    Log.d(TAG,"sleeping to make sure stream is set up");
    while (ois == null) {
        try {
            Thread.sleep(500);
        } catch (InterruptedException e2) {
            // TODO Auto-generated catch block
            e2.printStackTrace();
        }


    }
    Log.d(TAG, "done Sleeping");

    // Read out the 1 to make sure everything is okay 

    int i = 0;

    try {
        i = ois.read();
    } catch (IOException e) {
        Log.d(TAG, "error reading");
        e.printStackTrace();
    }


    Log.d(TAG,"I received an i of: " + i);
    Log.d(TAG,"OO Streams set up");




}

public void run() {...