Fields in interfaces and annotations are automatically `public static final`, and methods are `public abstract`. Classes, interfaces or annotations nested in an interface or annotation are automatically `public static` (all nested interfaces and annotations are automatically static). Nested enums are automatically `static`. For historical reasons, modifiers which are implied by the context are accepted by the compiler, but are superfluous. UnnecessaryModifier (Priority: 1, Ruleset: Code Style) https://docs.pmd-code.org/pmd-doc-7.14.0/pmd_rules_java_codestyle.html#unnecessarymodifier

Use of the keyword 'volatile' is generally used to fine tune a Java application, and therefore, requires a good expertise of the Java Memory Model. Moreover, its range of action is somewhat misknown. Therefore, the volatile keyword should not be used for maintenance purpose and portability. AvoidUsingVolatile (Priority: 1, Ruleset: Multithreading) https://docs.pmd-code.org/pmd-doc-7.14.0/pmd_rules_java_multithreading.html#avoidusingvolatile

Fields in interfaces and annotations are automatically `public static final`, and methods are `public abstract`. Classes, interfaces or annotations nested in an interface or annotation are automatically `public static` (all nested interfaces and annotations are automatically static). Nested enums are automatically `static`. For historical reasons, modifiers which are implied by the context are accepted by the compiler, but are superfluous. UnnecessaryModifier (Priority: 1, Ruleset: Code Style) https://docs.pmd-code.org/pmd-doc-7.14.0/pmd_rules_java_codestyle.html#unnecessarymodifier

Reports classes that may be made final because they cannot be extended from outside their compilation unit anyway. This is because all their constructors are private, so a subclass could not call the super constructor. ClassWithOnlyPrivateConstructorsShouldBeFinal (Priority: 1, Ruleset: Design) https://docs.pmd-code.org/pmd-doc-7.14.0/pmd_rules_java_design.html#classwithonlyprivateconstructorsshouldbefinal

Configurable naming conventions for formal parameters of methods and lambdas. This rule reports formal parameters which do not match the regex that applies to their specific kind (e.g. lambda parameter, or final formal parameter). Each regex can be configured through properties. By default this rule uses the standard Java naming convention (Camel case). FormalParameterNamingConventions (Priority: 1, Ruleset: Code Style) https://docs.pmd-code.org/pmd-doc-7.14.0/pmd_rules_java_codestyle.html#formalparameternamingconventions

Configurable naming conventions for formal parameters of methods and lambdas. This rule reports formal parameters which do not match the regex that applies to their specific kind (e.g. lambda parameter, or final formal parameter). Each regex can be configured through properties. By default this rule uses the standard Java naming convention (Camel case). FormalParameterNamingConventions (Priority: 1, Ruleset: Code Style) https://docs.pmd-code.org/pmd-doc-7.14.0/pmd_rules_java_codestyle.html#formalparameternamingconventions

Avoid the use of value in annotations when it's the only element. UnnecessaryAnnotationValueElement (Priority: 1, Ruleset: Code Style) https://docs.pmd-code.org/pmd-doc-7.14.0/pmd_rules_java_codestyle.html#unnecessaryannotationvalueelement

Configurable naming conventions for formal parameters of methods and lambdas. This rule reports formal parameters which do not match the regex that applies to their specific kind (e.g. lambda parameter, or final formal parameter). Each regex can be configured through properties. By default this rule uses the standard Java naming convention (Camel case). FormalParameterNamingConventions (Priority: 1, Ruleset: Code Style) https://docs.pmd-code.org/pmd-doc-7.14.0/pmd_rules_java_codestyle.html#formalparameternamingconventions

Uncommented Empty Constructor finds instances where a constructor does not contain statements, but there is no comment. By explicitly commenting empty constructors it is easier to distinguish between intentional (commented) and unintentional empty constructors. UncommentedEmptyConstructor (Priority: 1, Ruleset: Documentation) https://docs.pmd-code.org/pmd-doc-7.14.0/pmd_rules_java_documentation.html#uncommentedemptyconstructor