程序挂在 ObjectInputStream 的 readObject 方法上。答案

【问题标题】：program hangs on ObjectInputStream readObject method .程序挂在 ObjectInputStream 的 readObject 方法上。
【发布时间】：2012-02-27 06:27:07
【问题描述】：

我想在建立连接后共享包含（字符串名称、地址、标题、...和字节[]图片）的 Stuff 类型的对象，之后我的代码挂在 objectinputstream readObject() 函数上。不发生流式传输。谁能弄清楚我在哪里做错了。

private class ConnectedThread extends Thread {
        private final BluetoothSocket mmSocket;
        private final InputStream mmInStream;
        private final OutputStream mmOutStream;
        private ObjectOutputStream oos = null;
        private ObjectInputStream ois = null;

        public ConnectedThread(BluetoothSocket socket) {
            Log.d(TAG, "create ConnectedThread");
            mmSocket = socket;
            Log.d(TAG, "create a");
            InputStream tmpIn = null;
            Log.d(TAG, "create b");
            OutputStream tmpOut = null;

            // Get the BluetoothSocket input and output streams
            try {
                Log.d("connected thread constructor  before inputstream", "");
                tmpIn = socket.getInputStream();
                Log.d("connected thread constructor  inputstream",
                        tmpIn.toString());
                tmpOut = socket.getOutputStream();
                Log.d("connected thread constructor outputstream",
                        tmpOut.toString());
            } catch (IOException e) {
                Log.e(TAG, "temp sockets not created", e);
            }

            mmInStream = tmpIn;
            mmOutStream = tmpOut;

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

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

            // ********* ObjectOutputStream **********

            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);
            }

            // ********* ObjectInputStream **********

            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();

        }

        public void run() {
            Log.i(TAG, "BEGIN mConnectedThread");

我的代码此时挂起，永远不会前进。

        `// Keep listening to the InputStream while connected
        while (true) { 
            try {
                Log.d("Connected thread run ", "start while");

                try {

                    Stuff obj_rcv = (Stuff) ois.readObject();
                    Log.d("BTS", "rcv object " + obj_rcv.getName());

                    Message msg2 = mHandler
                            .obtainMessage(RemoteBusinessCard.MESSAGE_READ);
                    Bundle bundle = new Bundle();
                    bundle.putSerializable("person", obj_rcv);
                    msg2.setData(bundle);
                    mHandler.sendMessage(msg2);

                } catch (ClassNotFoundException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
                }
            } catch (IOException e) {
                Log.e(TAG, "disconnected", e);
                connectionLost();
                break;
            }
        }
    }

    /**
     * Write to the connected OutStream.
     * 
     * @param buffer
     *            The bytes to write
     */
    public void write(Stuff object) {
        try {
            Log.d("BTS", "inside write before" + object.getName());
            oos.writeObject(object);
            Log.d("BTS", "inside write after" + object.getName());
            oos.flush();
            oos.close();

        } catch (IOException e) {
            Log.e(TAG, "Exception during write", e);
        }
    }

    public void cancel() {
        try {
            mmSocket.close();
        } catch (IOException e) {
            Log.e(TAG, "close() of connect socket failed", e);
        }
    }
}`

【问题讨论】：

标签： android bluetooth objectoutputstream objectinputstream

【解决方案1】：

当您创建ObjectOutputStream 时，您必须确保套接字另一端的ObjectInputStream 也被适当地创建，因为 outputStream 总是向 inputStream 发送一个确认数据包并阻塞，直到它得到答案。

【讨论】：

如果 ObjectOutputStream 首先在主设备和从设备上执行，那么 ObjectInputStream 将如何接收数据，因为它还没有初始化！！
你必须轮流创建它们。例如客户端上的 InputStream 和服务器上的 OutputStream ，然后是客户端上的 OutputStream 和服务器上的 InputStream 。就像同时在相反的溪流中一样。

【解决方案2】：

这不是 java 的工作方式。您必须为输入和输出流创建两个单独的线程，以便您的逻辑正常工作。

【讨论】：

【解决方案3】：

outStream = new ObjectOutputStream(socket.getOutputStream());
outStream.flush();
inStream = new ObjectInputStream(socket.getInputStream());

首先在服务器和客户端创建输出流，刷新和输入流

【讨论】：