Example Depot

// Obtain a ByteBuffer; see Creating a ByteBuffer.
ByteBuffer buf = ByteBuffer.allocate(10);

// Create an output stream on the ByteBuffer
OutputStream os = newOutputStream(buf);

// Create an input stream on the ByteBuffer
InputStream is = newInputStream(buf);

// Returns an output stream for a ByteBuffer.
// The write() methods use the relative ByteBuffer put() methods.
public static OutputStream newOutputStream(final ByteBuffer buf) {
    return new OutputStream() {
        public synchronized void write(int b) throws IOException {
            buf.put((byte)b);
        }

        public synchronized void write(byte[] bytes, int off, int len) throws IOException {
            buf.put(bytes, off, len);
        }
    };
}

// Returns an input stream for a ByteBuffer.
// The read() methods use the relative ByteBuffer get() methods.
public static InputStream newInputStream(final ByteBuffer buf) {
    return new InputStream() {
        public synchronized int read() throws IOException {
            if (!buf.hasRemaining()) {
                return -1;
            }
            return buf.get();
        }

        public synchronized int read(byte[] bytes, int off, int len) throws IOException {
            // Read only what's left
            len = Math.min(len, buf.remaining());
            buf.get(bytes, off, len);
            return len;
        }
    };
}