Avoid unnecessary if-then-else statements when returning a boolean. The result of the conditional test can be returned instead. SimplifyBooleanReturns (Priority: 1, Ruleset: Design) https://docs.pmd-code.org/snapshot/pmd_rules_java_design.html#simplifybooleanreturns

Enforce a policy for braces on control statements. It is recommended to use braces on 'if ... else' statements and loop statements, even if they are optional. This usually makes the code clearer, and helps prepare the future when you need to add another statement. That said, this rule lets you control which statements are required to have braces via properties. From 6.2.0 on, this rule supersedes WhileLoopMustUseBraces, ForLoopMustUseBraces, IfStmtMustUseBraces, and IfElseStmtMustUseBraces. ControlStatementBraces (Priority: 1, Ruleset: Code Style) https://docs.pmd-code.org/snapshot/pmd_rules_java_codestyle.html#controlstatementbraces

Enforce a policy for braces on control statements. It is recommended to use braces on 'if ... else' statements and loop statements, even if they are optional. This usually makes the code clearer, and helps prepare the future when you need to add another statement. That said, this rule lets you control which statements are required to have braces via properties. From 6.2.0 on, this rule supersedes WhileLoopMustUseBraces, ForLoopMustUseBraces, IfStmtMustUseBraces, and IfElseStmtMustUseBraces. ControlStatementBraces (Priority: 1, Ruleset: Code Style) https://docs.pmd-code.org/snapshot/pmd_rules_java_codestyle.html#controlstatementbraces

Enforce a policy for braces on control statements. It is recommended to use braces on 'if ... else' statements and loop statements, even if they are optional. This usually makes the code clearer, and helps prepare the future when you need to add another statement. That said, this rule lets you control which statements are required to have braces via properties. From 6.2.0 on, this rule supersedes WhileLoopMustUseBraces, ForLoopMustUseBraces, IfStmtMustUseBraces, and IfElseStmtMustUseBraces. ControlStatementBraces (Priority: 1, Ruleset: Code Style) https://docs.pmd-code.org/snapshot/pmd_rules_java_codestyle.html#controlstatementbraces

Enforce a policy for braces on control statements. It is recommended to use braces on 'if ... else' statements and loop statements, even if they are optional. This usually makes the code clearer, and helps prepare the future when you need to add another statement. That said, this rule lets you control which statements are required to have braces via properties. From 6.2.0 on, this rule supersedes WhileLoopMustUseBraces, ForLoopMustUseBraces, IfStmtMustUseBraces, and IfElseStmtMustUseBraces. ControlStatementBraces (Priority: 1, Ruleset: Code Style) https://docs.pmd-code.org/snapshot/pmd_rules_java_codestyle.html#controlstatementbraces

Enforce a policy for braces on control statements. It is recommended to use braces on 'if ... else' statements and loop statements, even if they are optional. This usually makes the code clearer, and helps prepare the future when you need to add another statement. That said, this rule lets you control which statements are required to have braces via properties. From 6.2.0 on, this rule supersedes WhileLoopMustUseBraces, ForLoopMustUseBraces, IfStmtMustUseBraces, and IfElseStmtMustUseBraces. ControlStatementBraces (Priority: 1, Ruleset: Code Style) https://docs.pmd-code.org/snapshot/pmd_rules_java_codestyle.html#controlstatementbraces

Enforce a policy for braces on control statements. It is recommended to use braces on 'if ... else' statements and loop statements, even if they are optional. This usually makes the code clearer, and helps prepare the future when you need to add another statement. That said, this rule lets you control which statements are required to have braces via properties. From 6.2.0 on, this rule supersedes WhileLoopMustUseBraces, ForLoopMustUseBraces, IfStmtMustUseBraces, and IfElseStmtMustUseBraces. ControlStatementBraces (Priority: 1, Ruleset: Code Style) https://docs.pmd-code.org/snapshot/pmd_rules_java_codestyle.html#controlstatementbraces

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/snapshot/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/snapshot/pmd_rules_java_multithreading.html#avoidusingvolatile