Reports calls to overridable methods on `this` during object initialization. These are invoked on an incompletely constructed object and can be difficult to debug if overridden. This is because the subclass usually assumes that the superclass is completely initialized in all methods. If that is not the case, bugs can appear in the constructor, for instance, some fields that are still null may cause a NullPointerException or be stored somewhere else to blow up later. To avoid this problem, only use methods that are static, private, or final in constructors. Note that those methods also must not call overridable methods transitively to be safe. ConstructorCallsOverridableMethod (Priority: 1, Ruleset: Error Prone) https://docs.pmd-code.org/pmd-doc-7.10.0/pmd_rules_java_errorprone.html#constructorcallsoverridablemethod

Empty or auto-generated methods in an abstract class should be tagged as abstract. This helps to remove their inapproprate usage by developers who should be implementing their own versions in the concrete subclasses. EmptyMethodInAbstractClassShouldBeAbstract (Priority: 1, Ruleset: Code Style) https://docs.pmd-code.org/pmd-doc-7.10.0/pmd_rules_java_codestyle.html#emptymethodinabstractclassshouldbeabstract

Configurable naming conventions for field declarations. This rule reports variable declarations which do not match the regex that applies to their specific kind ---e.g. constants (static final), enum constant, final field. Each regex can be configured through properties. By default this rule uses the standard Java naming convention (Camel case), and uses the ALL_UPPER convention for constants and enum constants. FieldNamingConventions (Priority: 1, Ruleset: Code Style) https://docs.pmd-code.org/pmd-doc-7.10.0/pmd_rules_java_codestyle.html#fieldnamingconventions

Configurable naming conventions for field declarations. This rule reports variable declarations which do not match the regex that applies to their specific kind ---e.g. constants (static final), enum constant, final field. Each regex can be configured through properties. By default this rule uses the standard Java naming convention (Camel case), and uses the ALL_UPPER convention for constants and enum constants. FieldNamingConventions (Priority: 1, Ruleset: Code Style) https://docs.pmd-code.org/pmd-doc-7.10.0/pmd_rules_java_codestyle.html#fieldnamingconventions

Configurable naming conventions for field declarations. This rule reports variable declarations which do not match the regex that applies to their specific kind ---e.g. constants (static final), enum constant, final field. Each regex can be configured through properties. By default this rule uses the standard Java naming convention (Camel case), and uses the ALL_UPPER convention for constants and enum constants. FieldNamingConventions (Priority: 1, Ruleset: Code Style) https://docs.pmd-code.org/pmd-doc-7.10.0/pmd_rules_java_codestyle.html#fieldnamingconventions

Configurable naming conventions for field declarations. This rule reports variable declarations which do not match the regex that applies to their specific kind ---e.g. constants (static final), enum constant, final field. Each regex can be configured through properties. By default this rule uses the standard Java naming convention (Camel case), and uses the ALL_UPPER convention for constants and enum constants. FieldNamingConventions (Priority: 1, Ruleset: Code Style) https://docs.pmd-code.org/pmd-doc-7.10.0/pmd_rules_java_codestyle.html#fieldnamingconventions

Configurable naming conventions for field declarations. This rule reports variable declarations which do not match the regex that applies to their specific kind ---e.g. constants (static final), enum constant, final field. Each regex can be configured through properties. By default this rule uses the standard Java naming convention (Camel case), and uses the ALL_UPPER convention for constants and enum constants. FieldNamingConventions (Priority: 1, Ruleset: Code Style) https://docs.pmd-code.org/pmd-doc-7.10.0/pmd_rules_java_codestyle.html#fieldnamingconventions

Configurable naming conventions for field declarations. This rule reports variable declarations which do not match the regex that applies to their specific kind ---e.g. constants (static final), enum constant, final field. Each regex can be configured through properties. By default this rule uses the standard Java naming convention (Camel case), and uses the ALL_UPPER convention for constants and enum constants. FieldNamingConventions (Priority: 1, Ruleset: Code Style) https://docs.pmd-code.org/pmd-doc-7.10.0/pmd_rules_java_codestyle.html#fieldnamingconventions

Configurable naming conventions for field declarations. This rule reports variable declarations which do not match the regex that applies to their specific kind ---e.g. constants (static final), enum constant, final field. Each regex can be configured through properties. By default this rule uses the standard Java naming convention (Camel case), and uses the ALL_UPPER convention for constants and enum constants. FieldNamingConventions (Priority: 1, Ruleset: Code Style) https://docs.pmd-code.org/pmd-doc-7.10.0/pmd_rules_java_codestyle.html#fieldnamingconventions

Configurable naming conventions for field declarations. This rule reports variable declarations which do not match the regex that applies to their specific kind ---e.g. constants (static final), enum constant, final field. Each regex can be configured through properties. By default this rule uses the standard Java naming convention (Camel case), and uses the ALL_UPPER convention for constants and enum constants. FieldNamingConventions (Priority: 1, Ruleset: Code Style) https://docs.pmd-code.org/pmd-doc-7.10.0/pmd_rules_java_codestyle.html#fieldnamingconventions

The abstract class does not contain any abstract methods. An abstract class suggests an incomplete implementation, which is to be completed by subclasses implementing the abstract methods. If the class is intended to be used as a base class only (not to be instantiated directly) a protected constructor can be provided to prevent direct instantiation. AbstractClassWithoutAbstractMethod (Priority: 3, Ruleset: Best Practices) https://docs.pmd-code.org/pmd-doc-7.10.0/pmd_rules_java_bestpractices.html#abstractclasswithoutabstractmethod

Reports non-final fields whose value never changes once object initialization ends, and hence may be marked final. Note that this rule does not enforce that the field value be deeply immutable itself. An object can still have mutable state, even if all its member fields are declared final. This is referred to as shallow immutability. For more information on mutability, see *Effective Java, 3rd Edition, Item 17: Minimize mutability*. Limitations: We can only check private fields for now. ImmutableField (Priority: 3, Ruleset: Design) https://docs.pmd-code.org/pmd-doc-7.10.0/pmd_rules_java_design.html#immutablefield

Reports non-final fields whose value never changes once object initialization ends, and hence may be marked final. Note that this rule does not enforce that the field value be deeply immutable itself. An object can still have mutable state, even if all its member fields are declared final. This is referred to as shallow immutability. For more information on mutability, see *Effective Java, 3rd Edition, Item 17: Minimize mutability*. Limitations: We can only check private fields for now. ImmutableField (Priority: 3, Ruleset: Design) https://docs.pmd-code.org/pmd-doc-7.10.0/pmd_rules_java_design.html#immutablefield

Reports method and constructor parameters that can be made final because they are never reassigned within the body of the method. This rule ignores unused parameters so as not to overlap with the rule {% rule java/bestpractices/UnusedFormalParameter %}. It will also ignore the parameters of abstract methods. MethodArgumentCouldBeFinal (Priority: 3, Ruleset: Code Style) https://docs.pmd-code.org/pmd-doc-7.10.0/pmd_rules_java_codestyle.html#methodargumentcouldbefinal

Reports method and constructor parameters that can be made final because they are never reassigned within the body of the method. This rule ignores unused parameters so as not to overlap with the rule {% rule java/bestpractices/UnusedFormalParameter %}. It will also ignore the parameters of abstract methods. MethodArgumentCouldBeFinal (Priority: 3, Ruleset: Code Style) https://docs.pmd-code.org/pmd-doc-7.10.0/pmd_rules_java_codestyle.html#methodargumentcouldbefinal

Reports method and constructor parameters that can be made final because they are never reassigned within the body of the method. This rule ignores unused parameters so as not to overlap with the rule {% rule java/bestpractices/UnusedFormalParameter %}. It will also ignore the parameters of abstract methods. MethodArgumentCouldBeFinal (Priority: 3, Ruleset: Code Style) https://docs.pmd-code.org/pmd-doc-7.10.0/pmd_rules_java_codestyle.html#methodargumentcouldbefinal

Identical `catch` branches use up vertical space and increase the complexity of code without adding functionality. It's better style to collapse identical branches into a single multi-catch branch. IdenticalCatchBranches (Priority: 3, Ruleset: Code Style) https://docs.pmd-code.org/pmd-doc-7.10.0/pmd_rules_java_codestyle.html#identicalcatchbranches

Reports method and constructor parameters that can be made final because they are never reassigned within the body of the method. This rule ignores unused parameters so as not to overlap with the rule {% rule java/bestpractices/UnusedFormalParameter %}. It will also ignore the parameters of abstract methods. MethodArgumentCouldBeFinal (Priority: 3, Ruleset: Code Style) https://docs.pmd-code.org/pmd-doc-7.10.0/pmd_rules_java_codestyle.html#methodargumentcouldbefinal

Reports method and constructor parameters that can be made final because they are never reassigned within the body of the method. This rule ignores unused parameters so as not to overlap with the rule {% rule java/bestpractices/UnusedFormalParameter %}. It will also ignore the parameters of abstract methods. MethodArgumentCouldBeFinal (Priority: 3, Ruleset: Code Style) https://docs.pmd-code.org/pmd-doc-7.10.0/pmd_rules_java_codestyle.html#methodargumentcouldbefinal