a sample code to unsafe copy from byte[] to double[] (and vice-versa)

UnsafeCopy.java

public static void copyTest(String[] args) {
        Unsafe us = null;
        try {
            Field f = Unsafe.class.getDeclaredField("theUnsafe");

            f.setAccessible(true);
            us = (Unsafe) f.get(null);
            System.err.println(" oh my, I have it : " + us);
        } catch (Exception e) {
            e.printStackTrace();
        }

        int BYTE_ARRAY_OFFSET = us.arrayBaseOffset(byte[].class);
        int DOUBLE_ARRAY_OFFSET = us.arrayBaseOffset(double[].class);
        System.err.println(" Hello w , byte[] " + BYTE_ARRAY_OFFSET + " double [] " + DOUBLE_ARRAY_OFFSET);
        double[] srcArray = new double[1024];
        double[] dstArray = new double[1024];
        byte[] byteArray = new byte[1024*8];
        Random r = new Random();
        int i = 0;
        for(i=0;i<1024;i++){
            srcArray[i] = r.nextDouble();
        }
        us.copyMemory(srcArray, DOUBLE_ARRAY_OFFSET, byteArray, BYTE_ARRAY_OFFSET, 1024*8 );
        us.copyMemory(byteArray, BYTE_ARRAY_OFFSET, dstArray, DOUBLE_ARRAY_OFFSET, 1024*8);

        for(i=0;i<1024;i++) {
            System.err.println(" src : " + srcArray[i] + " desti " + dstArray[i]);
            assert (srcArray[i] == dstArray[i]);
        }
    }