Android outputStream.write发送多个消息 [英] Android outputStream.write send multiple messages

问题描述

是否可以用OutputStream.write(bytes[])发送多个消息，例如，当我两次调用函数编写func.write("hi"); func.write(" how are you");时，我会收到消息"concateneted"，如下所示:"hi how are you"，但是我想要两个不同的消息，有没有一种方法可以在不使用分隔符的情况下执行此操作，我的意思是知道另一台设备何时收到该消息，这是我的代码(它是android蓝牙示例):

private class ConnectedThread extends Thread {
    private final BluetoothSocket mmSocket;
    private final InputStream mmInStream;
    private final OutputStream mmOutStream;

    public ConnectedThread(BluetoothSocket socket, String socketType) {
        Log.d(TAG, "create ConnectedThread: " + socketType);
        mmSocket = socket;
        InputStream tmpIn = null;
        OutputStream tmpOut = null;

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

        mmInStream = tmpIn;
        mmOutStream = tmpOut;
    }

    public void run() {
        Log.i(TAG, "BEGIN mConnectedThread");
        byte[] buffer = new byte[1024];
        int bytes;

        // Keep listening to the InputStream while connected
        while (true) {
            try {
                // Read from the InputStream
                bytes = mmInStream.read(buffer);

                // Send the obtained bytes to the UI Activity
                mHandler.obtainMessage(BluetoothChat.MESSAGE_READ, bytes, -1, buffer)
                        .sendToTarget();
            } catch (IOException e) {
                Log.e(TAG, "disconnected", e);
                connectionLost();
                // Start the service over to restart listening mode
                BluetoothChatService.this.start();
                break;
            }
        }
    }

    /**
     * Write to the connected OutStream.
     * @param buffer  The bytes to write
     */
    public void write(byte[] buffer) {
        try {
            mmOutStream.write(buffer);

            // Share the sent message back to the UI Activity
            mHandler.obtainMessage(BluetoothChat.MESSAGE_WRITE, -1, -1, buffer)
                    .sendToTarget();
        } 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);
        }
    }
}

解决方案

致电:

mmOutStream.flush() 

每个消息部分之后.

public void write(byte[] buffer) {
    try {
        mmOutStream.write(buffer);

        //send what is already in buffer
        mmOutStream.flush();

        // Share the sent message back to the UI Activity
        mHandler.obtainMessage(BluetoothChat.MESSAGE_WRITE, -1, -1, buffer)
                .sendToTarget();
    } catch (IOException e) {
        Log.e(TAG, "Exception during write", e);
    }
}

从文档:

• flush()

  (刷新此输出流，并强制将所有缓冲的输出字节写出.刷新的一般约定是，调用它的指示是，如果先前写入的任何字节已被输出流的实现缓冲，则例如字节应立即写入其预期的目的地.

is there a way to send multiple messages with OutputStream.write(bytes[]), for example when i call twice my function to write func.write("hi"); func.write(" how are you");, I receive the message "concateneted" like this: "hi how are you", but i want two different messages, is there a way to do it without using separators in my message, i mean know when the other device receives the message, here is my code (its the android bluetooth sample):

private class ConnectedThread extends Thread {
    private final BluetoothSocket mmSocket;
    private final InputStream mmInStream;
    private final OutputStream mmOutStream;

    public ConnectedThread(BluetoothSocket socket, String socketType) {
        Log.d(TAG, "create ConnectedThread: " + socketType);
        mmSocket = socket;
        InputStream tmpIn = null;
        OutputStream tmpOut = null;

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

        mmInStream = tmpIn;
        mmOutStream = tmpOut;
    }

    public void run() {
        Log.i(TAG, "BEGIN mConnectedThread");
        byte[] buffer = new byte[1024];
        int bytes;

        // Keep listening to the InputStream while connected
        while (true) {
            try {
                // Read from the InputStream
                bytes = mmInStream.read(buffer);

                // Send the obtained bytes to the UI Activity
                mHandler.obtainMessage(BluetoothChat.MESSAGE_READ, bytes, -1, buffer)
                        .sendToTarget();
            } catch (IOException e) {
                Log.e(TAG, "disconnected", e);
                connectionLost();
                // Start the service over to restart listening mode
                BluetoothChatService.this.start();
                break;
            }
        }
    }

    /**
     * Write to the connected OutStream.
     * @param buffer  The bytes to write
     */
    public void write(byte[] buffer) {
        try {
            mmOutStream.write(buffer);

            // Share the sent message back to the UI Activity
            mHandler.obtainMessage(BluetoothChat.MESSAGE_WRITE, -1, -1, buffer)
                    .sendToTarget();
        } 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);
        }
    }
}

解决方案

Call:

mmOutStream.flush() 

after each message part.

public void write(byte[] buffer) {
    try {
        mmOutStream.write(buffer);

        //send what is already in buffer
        mmOutStream.flush();

        // Share the sent message back to the UI Activity
        mHandler.obtainMessage(BluetoothChat.MESSAGE_WRITE, -1, -1, buffer)
                .sendToTarget();
    } catch (IOException e) {
        Log.e(TAG, "Exception during write", e);
    }
}

From the docs:

• flush()

  (Flushes this output stream and forces any buffered output bytes to be written out. The general contract of flush is that calling it is an indication that, if any bytes previously written have been buffered by the implementation of the output stream, such bytes should immediately be written to their intended destination.

这篇关于Android outputStream.write发送多个消息的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！