jodd-core/src/main/java/jodd/util/StringUtil.java
public static String suffix(String string, final String suffix) {
		if (!string.endsWith(suffix)) {
			string += suffix;
		}
		return string;
	}
public static String suffix(String string, final String suffix) {
		if (!string.endsWith(suffix)) {
			string += suffix;
		}
		return string;
	}
Appends suffix if doesn't exist.