GuidUtil

GuidUtil.java

global with sharing class GuidUtil {
	private static String kHexChars = '0123456789abcdef';

	global static String NewGuid() {
		String returnValue = '';
		Integer nextByte = 0;
		for (Integer i=0; i<16; i++) {
			if (i==4 || i==6 || i==8 || i==10) 
				returnValue += '-';
			nextByte = (Math.round(Math.random() * 255)-128) & 255;
			if (i==6) {
				nextByte = nextByte & 15;
				nextByte = nextByte | (4 << 4);
			}
			if (i==8) {
				nextByte = nextByte & 63;
				nextByte = nextByte | 128;
			}
			returnValue += getCharAtIndex(kHexChars, nextByte >> 4);
			returnValue += getCharAtIndex(kHexChars, nextByte & 15);
		}
		return returnValue;
	}

	global static String getCharAtIndex(String str, Integer index) {
		if (str == null) return null;
		if (str.length() <= 0) return str;    
		if (index == str.length()) return null;    
		return str.substring(index, index+1);
	}
}