通过 Android socket 发送和接收 Bytes 两个问题：

Question

I've got an issue with JAVA/ Android studio surrounding sending and receiving bytes. Notably: sending and receiving byte values over 127 using TCP sockets.

I receive data here:

    try {
        mBufferOut = new PrintWriter(socket.getOutputStream());
        mBufferIn = new InputStreamReader(socket.getInputStream(), "UTF-8");
        char[] buffer = new char[64];

        while (mRun) {
mBufferIn.read(buffer);
            mServerMessage = String.valueOf(buffer);
            if (mServerMessage != null && mMessageListener != null) {
                mMessageListener.messageReceived(mServerMessage);
            }
            mServerMessage = null;
        }

and send data here:

public void sendMessage(final char[] message) {
        Runnable runnable = new Runnable() {
            @Override
            public void run() {
                if (mBufferOut != null) {
                    mBufferOut.write(message);
                    mBufferOut.flush();
                }
            }
        };
        Thread thread = new Thread(runnable);
        thread.start();
    }

When I receive data, all data over 127 in values is returned as "231, 191, 189". When I send data, every byte with a value x over 127 is returned as "195, x".

How can I cleanly solve this issue?

Answer 1

I don't think that sending a String as array of char , and using String.valueOf() to restore it is the right way.

String already has a mechanism to convert itself to/from bytes:

byte[] bytes = text.getBytes("UTF-8");
...
String text = new String(bytes, "UTF-8");

Try using this 2 methods to convert String to byte[] and vice versa.