Java：如何快速复制BufferedImage的像素？（包括单元测试）

private static void copySrcIntoDstAt(final BufferedImage src,        final BufferedImage dst, final int dx, final int dy) {    int[] srcbuf = ((DataBufferInt) src.getRaster().getDataBuffer()).getData();    int[] dstbuf = ((DataBufferInt) dst.getRaster().getDataBuffer()).getData();    int width = src.getWidth();    int height = src.getHeight();    int dstoffs = dx + dy * dst.getWidth();    int srcoffs = 0;    for (int y = 0 ; y < height ; y++ , dstoffs+= dst.getWidth(), srcoffs += width ) {        System.arraycopy(srcbuf, srcoffs , dstbuf, dstoffs, width);    }}