public static boolean startWith(String source, String target) {
		if (source == null || target == null) {
			throw new IllegalArgumentException();
		}
		char[] sourceCharArray = source.toCharArray();
		char[] targetCharArray = target.toCharArray();
		for (int i = 0, len = targetCharArray.length; i < len; i++) {
			if (sourceCharArray[i] != targetCharArray[i]) {
				return false;
			}
		}
		return true;
	}