public static String substringBeforeLast(String sourceStr, String expr) {
		if (isEmpty(sourceStr) || expr == null) {
			return sourceStr;
		}
		if (expr.length() == 0) {
			return sourceStr;
		}
		int pos = sourceStr.lastIndexOf(expr);
		if (pos == -1) {
			return sourceStr;
		}
		return sourceStr.substring(0, pos);
	}