For classes that only have static methods, consider making them utility classes. Note that this doesn't apply to abstract classes, since their subclasses may well include non-static methods. Also, if you want this class to be a utility class, remember to add a private constructor to prevent instantiation. (Note, that this use was known before PMD 5.1.0 as UseSingleton). UseUtilityClass (Priority: 1, Ruleset: Design) https://docs.pmd-code.org/snapshot/pmd_rules_java_design.html#useutilityclass