Whenever using a log level, one should check if it is actually enabled, or otherwise skip the associate String creation and manipulation, as well as any method calls. An alternative to checking the log level are substituting parameters, formatters or lazy logging with lambdas. The available alternatives depend on the actual logging framework. GuardLogStatement (Priority: 2, Ruleset: Best Practices) https://docs.pmd-code.org/snapshot/pmd_rules_java_bestpractices.html#guardlogstatement

Whenever using a log level, one should check if it is actually enabled, or otherwise skip the associate String creation and manipulation, as well as any method calls. An alternative to checking the log level are substituting parameters, formatters or lazy logging with lambdas. The available alternatives depend on the actual logging framework. GuardLogStatement (Priority: 2, Ruleset: Best Practices) https://docs.pmd-code.org/snapshot/pmd_rules_java_bestpractices.html#guardlogstatement

Whenever using a log level, one should check if it is actually enabled, or otherwise skip the associate String creation and manipulation, as well as any method calls. An alternative to checking the log level are substituting parameters, formatters or lazy logging with lambdas. The available alternatives depend on the actual logging framework. GuardLogStatement (Priority: 2, Ruleset: Best Practices) https://docs.pmd-code.org/snapshot/pmd_rules_java_bestpractices.html#guardlogstatement

Whenever using a log level, one should check if it is actually enabled, or otherwise skip the associate String creation and manipulation, as well as any method calls. An alternative to checking the log level are substituting parameters, formatters or lazy logging with lambdas. The available alternatives depend on the actual logging framework. GuardLogStatement (Priority: 2, Ruleset: Best Practices) https://docs.pmd-code.org/snapshot/pmd_rules_java_bestpractices.html#guardlogstatement

Whenever using a log level, one should check if it is actually enabled, or otherwise skip the associate String creation and manipulation, as well as any method calls. An alternative to checking the log level are substituting parameters, formatters or lazy logging with lambdas. The available alternatives depend on the actual logging framework. GuardLogStatement (Priority: 2, Ruleset: Best Practices) https://docs.pmd-code.org/snapshot/pmd_rules_java_bestpractices.html#guardlogstatement

Whenever using a log level, one should check if it is actually enabled, or otherwise skip the associate String creation and manipulation, as well as any method calls. An alternative to checking the log level are substituting parameters, formatters or lazy logging with lambdas. The available alternatives depend on the actual logging framework. GuardLogStatement (Priority: 2, Ruleset: Best Practices) https://docs.pmd-code.org/snapshot/pmd_rules_java_bestpractices.html#guardlogstatement

Whenever using a log level, one should check if it is actually enabled, or otherwise skip the associate String creation and manipulation, as well as any method calls. An alternative to checking the log level are substituting parameters, formatters or lazy logging with lambdas. The available alternatives depend on the actual logging framework. GuardLogStatement (Priority: 2, Ruleset: Best Practices) https://docs.pmd-code.org/snapshot/pmd_rules_java_bestpractices.html#guardlogstatement

Whenever using a log level, one should check if it is actually enabled, or otherwise skip the associate String creation and manipulation, as well as any method calls. An alternative to checking the log level are substituting parameters, formatters or lazy logging with lambdas. The available alternatives depend on the actual logging framework. GuardLogStatement (Priority: 2, Ruleset: Best Practices) https://docs.pmd-code.org/snapshot/pmd_rules_java_bestpractices.html#guardlogstatement

Whenever using a log level, one should check if it is actually enabled, or otherwise skip the associate String creation and manipulation, as well as any method calls. An alternative to checking the log level are substituting parameters, formatters or lazy logging with lambdas. The available alternatives depend on the actual logging framework. GuardLogStatement (Priority: 2, Ruleset: Best Practices) https://docs.pmd-code.org/snapshot/pmd_rules_java_bestpractices.html#guardlogstatement

Whenever using a log level, one should check if it is actually enabled, or otherwise skip the associate String creation and manipulation, as well as any method calls. An alternative to checking the log level are substituting parameters, formatters or lazy logging with lambdas. The available alternatives depend on the actual logging framework. GuardLogStatement (Priority: 2, Ruleset: Best Practices) https://docs.pmd-code.org/snapshot/pmd_rules_java_bestpractices.html#guardlogstatement

Node.js 20 actions are deprecated. The following actions are running on Node.js 20 and may not work as expected: actions/checkout@v3, actions/setup-java@v3, pmd/pmd-github-action@v2. Actions will be forced to run with Node.js 24 by default starting June 2nd, 2026. Node.js 20 will be removed from the runner on September 16th, 2026. Please check if updated versions of these actions are available that support Node.js 24. To opt into Node.js 24 now, set the FORCE_JAVASCRIPT_ACTIONS_TO_NODE24=true environment variable on the runner or in your workflow file. Once Node.js 24 becomes the default, you can temporarily opt out by setting ACTIONS_ALLOW_USE_UNSECURE_NODE_VERSION=true. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

Calls to a collection's `toArray(E[])` method should specify a target array of zero size. This allows the JVM to optimize the memory allocation and copying as much as possible. Previous versions of this rule (pre PMD 6.0.0) suggested the opposite, but current JVM implementations perform always better, when they have full control over the target array. And allocation an array via reflection is nowadays as fast as the direct allocation. See also [Arrays of Wisdom of the Ancients](https://shipilev.net/blog/2016/arrays-wisdom-ancients/) Note: If you don't need an array of the correct type, then the simple `toArray()` method without an array is faster, but returns only an array of type `Object[]`. OptimizableToArrayCall (Priority: 3, Ruleset: Performance) https://docs.pmd-code.org/snapshot/pmd_rules_java_performance.html#optimizabletoarraycall

A logger should normally be defined private static final and be associated with the correct class. `private final Log log;` is also allowed for rare cases where loggers need to be passed around, with the restriction that the logger needs to be passed into the constructor. ProperLogger (Priority: 3, Ruleset: Error Prone) https://docs.pmd-code.org/snapshot/pmd_rules_java_errorprone.html#properlogger

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: 3, 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: 3, Ruleset: Code Style) https://docs.pmd-code.org/snapshot/pmd_rules_java_codestyle.html#controlstatementbraces

Catching Throwable errors is not recommended since its scope is very broad. It includes runtime issues such as OutOfMemoryError that should be exposed and managed separately. **Deprecated:** This rule is deprecated since PMD 7.18.0 and will be removed with PMD 8.0.0. This rule has been subsumed by {% rule AvoidCatchingGenericException %}, which is now configurable as to which exceptions cause a violation. AvoidCatchingThrowable (Priority: 3, Ruleset: Error Prone) https://docs.pmd-code.org/snapshot/pmd_rules_java_errorprone.html#avoidcatchingthrowable

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: 3, Ruleset: Code Style) https://docs.pmd-code.org/snapshot/pmd_rules_java_codestyle.html#controlstatementbraces

Parenthesized expressions are used to override the default operator precedence rules. Parentheses whose removal would not change the relative nesting of operators are unnecessary, because they don't change the semantics of the enclosing expression. Some parentheses that strictly speaking are unnecessary, may still be considered useful for readability. This rule allows to ignore violations on two kinds of unnecessary parentheses: - "Clarifying" parentheses, which separate operators of difference precedence. While unnecessary, they make precedence rules explicit, which may be useful for rarely used operators. For example: ```java (a + b) & c // is equivalent to `a + b & c`, but probably clearer ``` Unset the property `ignoreClarifying` to report them. - "Balancing" parentheses, which are unnecessary but visually balance out another pair of parentheses around an equality operator. For example, those two expressions are equivalent: ```java (a == null) != (b == null) a == null != (b == null) ``` The parentheses on the right are required, and the parentheses on the left are just more visually pleasing. Unset the property `ignoreBalancing` to report them. UselessParentheses (Priority: 4, Ruleset: Code Style) https://docs.pmd-code.org/snapshot/pmd_rules_java_codestyle.html#uselessparentheses

Reports usages of primitive wrapper constructors. They are deprecated since Java 9 and should not be used. Even before Java 9, they can be replaced with usage of the corresponding static `valueOf` factory method (which may be automatically inserted by the compiler since Java 1.5). This has the advantage that it may reuse common instances instead of creating a new instance each time. Note that for `Boolean`, the named constants `Boolean.TRUE` and `Boolean.FALSE` are preferred instead of `Boolean.valueOf`. PrimitiveWrapperInstantiation (Priority: 3, Ruleset: Best Practices) https://docs.pmd-code.org/snapshot/pmd_rules_java_bestpractices.html#primitivewrapperinstantiation

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: 3, Ruleset: Code Style) https://docs.pmd-code.org/snapshot/pmd_rules_java_codestyle.html#controlstatementbraces