DirectBuffer release example

BufferUtils.java

/**
     * Releases ByteBuffer if possible. Call semantics should be as follows:
     * <p/>
     * ByteBuffer buffer = ....
     * <p/>
     * buffer = release(buffer);
     *
     * @param buffer direct byte buffer
     * @return null if buffer is released or same buffer if release is not possible.
     */
    public static <T extends ByteBuffer> T release(final T buffer) {
        if (buffer != null) {
            if (buffer instanceof DirectBuffer) {
                Cleaner cleaner = ((DirectBuffer) buffer).cleaner();
                if (cleaner != null) {
                    cleaner.clean();
                    return null;
                }
            }
        }
        return buffer;
    }