U.java

import java.nio.ByteBuffer;

public class U {

    public static void main(String[] args) {
        int i = Integer.MAX_VALUE;
        int xint = 1419258235;
        int yint = 1411392235;
        System.out.println("let x = " + xint);
        System.out.println("let y = " + yint);
        System.out.println();
        ByteBuffer xbuf = wrap(xint);
        ByteBuffer ybuf = wrap(yint);
        System.out.println("java thinks the integer x is greater than the integer y");
        System.out.println("    Integer.compare(x, y) => " + Integer.compare(xint, yint));
        System.out.println();
        System.out.println("cass thinks a byte buffer of x is less than a byte buffer of y");
        System.out.println("    xbuf.compareTo(ybuf) => " + xbuf.compareTo(ybuf));
        System.out.println();
        byte x0 = xbuf.get(0);
        byte x1 = xbuf.get(1);
        byte x2 = xbuf.get(2);
        byte x3 = xbuf.get(3);
        byte y0 = ybuf.get(0);
        byte y1 = ybuf.get(1);
        byte y2 = ybuf.get(2);
        byte y3 = ybuf.get(3);
        System.out.println("lets compare each individual byte");
        System.out.println();
        System.out.println("unsigned comparison using Integer.compare(x, y)");
        System.out.format("%4s  %4s\n", "x", "y");
        System.out.println("----------------");
        System.out.format("%4d  %4d  %4d\n", unsigned(x0), unsigned(y0), Integer.compare(unsigned(x0), unsigned(y0)));
        System.out.format("%4d  %4d  %4d <--\n", unsigned(x1), unsigned(y1), Integer.compare(unsigned(x1), unsigned(y1)));
        System.out.format("%4d  %4d  %4d\n", unsigned(x2), unsigned(y2), Integer.compare(unsigned(x2), unsigned(y2)));
        System.out.format("%4d  %4d  %4d\n", unsigned(x3), unsigned(y3), Integer.compare(unsigned(x3), unsigned(y3)));
        System.out.println();
        System.out.println("signed comparison using Byte.compare(x, y)");
        System.out.format("%4s  %4s\n", "x", "y");
        System.out.println("----------------");
        System.out.format("%4d  %4d  %4d\n", x0, y0, Byte.compare(x0, y0));
        System.out.format("%4d  %4d  %4d <--\n", x1, y1, Byte.compare(x1, y1));
        System.out.format("%4d  %4d  %4d\n", x2, y2, Byte.compare(x2, y2));
        System.out.format("%4d  %4d  %4d\n", x3, y3, Byte.compare(x3, y3));
        System.out.println();
        System.out.println("notice anything similar?");

//        System.out.println("--------");
//        System.out.println("xint = " + xint + "\nxint + " + fromBuffer(xbuf));
//        System.out.println("--------");
//        System.out.println("yint = " + yint + "\nyint + " + fromBuffer(ybuf));
//        System.out.println("--------");

//        System.out.println(unsigned((byte) -128));
//        System.out.println(unsigned((byte) 127));
//        System.out.println(unsigned((byte) 1));
//        System.out.println(unsigned((byte) -1));
    }

    public static ByteBuffer wrap(int i) {
        byte a = (byte)((i & 0x000000FF));
        byte b = (byte)((i & 0x0000FF00) >> 8);
        byte c = (byte)((i & 0x00FF0000) >> 16);
        byte d = (byte)((i & 0xFF000000) >> 24);
//        System.out.println(d);
//        System.out.println(c);
//        System.out.println(b);
//        System.out.println(a);
        return ByteBuffer.wrap(new byte[]{d, c, b, a});
    }

    public static int unsigned(byte i) {
        return (i < 0) ? ((int) i) & 0x000000FF : i;
    }

    public static int fromBuffer(ByteBuffer buf) {
        return ((unsigned(buf.get(0)) << 24)
              + (unsigned(buf.get(1)) << 16)
              + (unsigned(buf.get(2)) << 8)
              + (unsigned(buf.get(3))));
    }

}