Cleaning ByteBuffer

Question

A very simple problem: I am reading one SocketChannel and would like to write the results in another SocketChannel. I use the Selector object, so I wait until one SocketChannel is readable, upload the data to ByteBuffer, and then when the next SocketChannel is writable, I unload ByteBuffer. Still. However, there seems to be no way to “clear” ByteBuffer, so I cannot do any checks to know when the new data arrived.

I tried the .clear () method, but apparently it does not clear the buffer, but simply resets the buffer position to 1.

I never program in Java so naked with me if this is a problem with the "obvious" solution ...

Here is a sample code:

ByteBuffer channel1buf = ByteBuffer.allocate(1024);
ByteBuffer channel2buf = ByteBuffer.allocate(1024);

if (key.isReadable()) {
    if (key.channel().equals(channel1)) {
        channel1.read(channel2buf);
    } else if (key.channel().equals(channel2)) {
        channel2.read(channel1buf);
    }
} else if (key.isWritable()) {
    if (key.channel().equals(channel1) && channel1buf.asCharBuffer().length() > 0) {
        channel1.write(channel1buf);
        /* some way to clear channel1buf */
    } else /* same idea for channel2... */
}

Thank!

Answer 1

Buffer.clear , , getPosition() > 0, , - , ...?

Answer 2

​​ , , .

channel1buf.clear();
//zerolize buff manually
channel1buf.put(new byte[1024]);
channel1buf.clear();