checkstyle-openrewrite-recipes

This OpenRewrite recipe automatically fixes Checkstyle violations in your Java project by analyzing the Checkstyle report and applying code transformations to resolve common issues.

Prerequisites

You need a Java project that already has the Checkstyle plugin configured and running.

Setup

First, add the OpenRewrite plugin and our autofix recipe dependency to your build configuration.

Example:

<plugin>
  <groupId>org.openrewrite.maven</groupId>
  <artifactId>rewrite-maven-plugin</artifactId>
  <version>${rewrite.maven.plugin}</version>
  <configuration>
    <activeRecipes>
      <recipe>CheckstyleAutoFix</recipe>
    </activeRecipes>
  </configuration>
  <dependencies>
    <dependency>
      <groupId>com.puppycrawl.tools</groupId>
      <artifactId>checkstyle-openrewrite-recipes</artifactId>
      <version>1.0.0</version>
    </dependency>
  </dependencies>
</plugin>

Configuration

Create a rewrite.yml file in your project root:

---
type: specs.openrewrite.org/v1beta/recipe
name: CheckstyleAutoFix
displayName: Checkstyle Auto Fix
description: Automatically fix Checkstyle violations
recipeList:
  - org.checkstyle.autofix.CheckstyleAutoFix:
      violationReportPath: "target/checkstyle/checkstyle-report.xml"
      configurationPath: "config/checkstyle.xml"
      propertiesPath: "config/checkstyle.properties"

Parameters:

• violationReportPath: Path to Checkstyle XML report (required)
• configurationPath: Path to Checkstyle configuration file (required)
• propertiesPath: Path to Checkstyle properties file (optional)

How to use it

The autofix process works in two steps: first generate a Checkstyle report, then run the autofix recipe.

mvn checkstyle:check    # Generate the violation report
mvn rewrite:run         # Apply the fixes

OpenRewrite Recipe Coverage for Checkstyle Checks

This table tracks the auto-fix support status of OpenRewrite recipes for each Checkstyle check. Organized by Checkstyle categories, it helps contributors identify which checks are:

• Fully supported via auto-fix
• Partially supported
• Not feasible to auto-fix

Status Legend

Status	Meaning
🔵	Implemented – Recipes have been created for these checks
🟡	Partial Coverage – Recipes exist but only cover specific violation scenarios
🟢	Planned – Feasible to implement, but no recipe exists yet
🔴	Not Supported – Cannot be implemented or not feasible to auto-fix
⚪	Pending Review – Automatically detected requires human review to determine feasibility

Annotations

Status	Check	Coverage Notes
🔵	AnnotationLocation
🔵	AnnotationOnSameLine
🔴	AnnotationUseStyle	Standardize annotation syntax
🔵	MissingDeprecated
🔵	MissingOverride
🟢	MissingOverrideOnRecordAccessor
🟢	OpenjdkAnnotationLocation
🟢	PackageAnnotation
🔴	SuppressWarnings	Remove inappropriate suppressions
🔴	SuppressWarningsHolder	Infrastructural module for SuppressWarningsFilter

Block Checks

Status	Check	Coverage Notes
🔴	AvoidNestedBlocks	Requires code restructuring
🟢	EmptyBlock
🟢	EmptyCatchBlock
🟢	LeftCurly
🟢	NeedBraces
🟢	RightCurly

Class Design

Status	Check	Coverage Notes
🔴	DesignForExtension	Requires design decisions (final/abstract)
🔵	FinalClass
🟢	HideUtilityClassConstructor
🟢	InnerTypeLast
🔴	InterfaceIsType	Remove non-type interface members
🔴	MutableException	Make exception fields final
🔴	OneTopLevelClass	Split into separate files
🟢	SealedShouldHavePermitsList
🔴	ThrowsCount	Reduce throws declarations
🔴	VisibilityModifier	Change visibility modifiers

Coding

Status	Check	Coverage Notes
🔵	ArrayTrailingComma
🔴	AvoidDoubleBraceInitialization	Requires refactoring initialization logic
🔴	AvoidInlineConditionals	Requires extracting to if-else statements
🔵	AvoidNoArgumentSuperConstructorCall
🔵	ConstructorsDeclarationGrouping
🔴	CovariantEquals	Requires implementing proper equals(Object)
🟢	DeclarationOrder
🟢	DefaultComesLast
🔵	EmptyStatement
🟢	EqualsAvoidNull
🔴	EqualsHashCode	Implement proper equals/hashCode pair
🟢	ExplicitInitialization
⚪	ExpressionOverBlockLambda
🔴	FallThrough	Add break statements or intentional comments
🔵	FinalLocalVariable
🔴	HiddenField	Rename variables or use this. prefix
🔴	IllegalCatch	Change catch block exception types
🔴	IllegalInstantiation	Replace with factory methods
🔴	IllegalSymbol
🔴	IllegalThrows	Change throws declarations
🔴	IllegalToken	Replace illegal tokens
🔴	IllegalTokenText	Change token text
🔴	IllegalType	Replace with allowed types
🔴	InnerAssignment	Extract assignments to separate statements
🔴	MagicNumber	Extract to named constants
🔴	MatchXpath	Context-dependent XPath violations
🔴	MissingCtor	Add explicit constructor
🟢	MissingNullCaseInSwitch
🔵	MissingSwitchDefault
🔴	ModifiedControlVariable	Restructure loop logic
🔴	MultipleStringLiterals	Extract to constants
🟢	MultipleVariableDeclarations
🔴	NestedForDepth	Requires loop restructuring
🔴	NestedIfDepth	Requires conditional restructuring
🔴	NestedTryDepth	Requires exception handling restructuring
🟢	NoArrayTrailingComma
🔴	NoClone	Remove clone() method
🟢	NoEnumTrailingComma
🔴	NoFinalizer	Remove finalize() method
🟢	OneStatementPerLine
🟢	OverloadMethodsDeclarationOrder
🟢	PackageDeclaration
🔴	ParameterAssignment
🔴	PatternVariableAssignment
🟢	RequireThis
🔴	ReturnCount
🟢	SimplifyBooleanExpression
🟢	SimplifyBooleanReturn
🟢	StringLiteralEquality
🔴	SuperClone
🟢	SuperFinalize
🟢	TextBlockGoogleStyleFormatting
🟢	UnnecessaryTypeArgumentsWithRecordPattern
🟢	UnnecessaryNullCheckWithInstanceOf
🔵	UnnecessaryParentheses
🟢	UnnecessarySemicolonAfterOuterTypeDeclaration
🟢	UnnecessarySemicolonAfterTypeMemberDeclaration
🟢	UnnecessarySemicolonInEnumeration
🟢	UnnecessarySemicolonInTryWithResources
🟢	UnusedCatchParameterShouldBeUnnamed
🟢	UnusedLambdaParameterShouldBeUnnamed
🔵	UnusedLocalVariable
⚪	UnusedPrivateField
🟢	UnusedTryResourceShouldBeUnnamed
🔵	UseEnhancedSwitch
🔴	VariableDeclarationUsageDistance
🔴	WhenShouldBeUsed

Headers

Status	Check	Coverage Notes
🟡	Header	only java files are fixed.
🔴	MultiFileRegexpHeader	Fix header content
🔴	RegexpHeader	Fix header content

Imports

Status	Check	Coverage Notes
⚪	AvoidModuleImport
🔵	AvoidStarImport
🟢	AvoidStaticImport
🟢	CustomImportOrder
🔴	IllegalImport	Replace with allowed imports
🔴	ImportControl	Restructure imports per rules
🟢	ImportOrder
⚪	ModuleImportOrder
🔵	RedundantImport
⚪	UnnecessaryFullyQualifiedType
🔵	UnusedImports

Javadoc Comments

Status	Check	Coverage Notes
🟢	AtclauseOrder
🟢	IllegalBlockTag
⚪	InappropriateJavadocBlockTagsOnField
⚪	InappropriateJavadocBlockTagsOnPackage
⚪	InappropriateJavadocBlockTagsOnType
🟢	InvalidJavadocPosition
🟢	JavadocBlockTagLocation
🟢	JavadocContentLocation
⚪	JavadocEndCommentDelimiter
🟢	JavadocLeadingAsteriskAlign
⚪	JavadocLinkFirstOccurrence
⚪	JavadocLinkWellKnownApi
🔴	JavadocMethod	Add/fix method documentation
🟢	JavadocMissingLeadingAsterisk
🟢	JavadocMissingWhitespaceAfterAsterisk
⚪	JavadocNoErrorInThrowsTag
🔴	JavadocPackage	Create package-info.java
🟢	JavadocParagraph
⚪	JavadocParamOrder
🔴	JavadocRegexp	Context-dependent pattern matching
🟢	JavadocTagContinuationIndentation
⚪	JavadocThrowsOrder
🔴	JavadocType	Add/fix type documentation
🔴	JavadocVariable	Add variable documentation
🔴	MissingJavadocMethod	Add method documentation
🔴	MissingJavadocPackage	Add package documentation
🔴	MissingJavadocType	Add type documentation
🔴	NonEmptyAtclauseDescription	Add tag descriptions
⚪	PreferCodeOrSnippetJavadocInlineTag
🟢	PreferLiteralJavadocInlineTag
🟢	RequireEmptyLineBeforeBlockTagGroup
🟢	SingleLineJavadoc
🔴	SummaryJavadoc	Rewrite summary sentences
🔴	WriteTag	Add/fix custom Javadoc tags

Metrics

Status	Check	Coverage Notes
🔴	BooleanExpressionComplexity	Requires breaking down complex expressions
🔴	ClassDataAbstractionCoupling	Requires architectural changes
🔴	ClassFanOutComplexity	Requires architectural refactoring
🔴	CyclomaticComplexity	Requires method decomposition
🔴	JavaNCSS	Requires code simplification
🔴	NPathComplexity	Requires method decomposition

Miscellaneous

Status	Check	Coverage Notes
🟢	ArrayTypeStyle
🔴	AvoidEscapedUnicodeCharacters	Need to determine appropriate replacements
🟢	CommentsIndentation
⚪	ModuleDirectiveOrder
🟢	MultilineCommentLeadingAsteriskPresence
🔴	DescendantToken	Context-dependent token restrictions
🟢	FinalParameters
🔵	HexLiteralCase
🟢	Indentation
🟢	LineEnding
🔵	NewlineAtEndOfFile
🔴	NoCodeInFile	Add code or remove file
🔵	NumericalPrefixesInfixesSuffixesCharacterCase
🔴	OrderedProperties	Reorder properties
🔴	OuterTypeFilename	Rename file or class
🔴	TodoComment	Resolve TODO comments
🟢	TrailingComment
🔴	Translation	Fix property file translations
🟢	UncommentedMain
🔴	UniqueProperties	Remove duplicate properties
🔵	UpperEll

Modifiers

Status	Check	Coverage Notes
🟢	AnnotatedDeclarationVisibility
🟢	ClassMemberImpliedModifier
🟢	InterfaceMemberImpliedModifier
🟢	ModifierOrder
🟢	RedundantModifier

Naming Conventions

Status	Check	Coverage Notes
🔴	AbbreviationAsWordInName	Requires semantic understanding of abbreviations and context
🟡	AbstractClassName	Partially covered by renaming abstract class names to match the configured pattern.
🟢	CatchParameterName
🟢	ClassTypeParameterName
🟢	ConstantName
🔴	GoogleMethodName	Requires manual renaming
🔴	GoogleNonConstantFieldName
🔴	IllegalIdentifierName	Rename identifiers
🟢	InterfaceTypeParameterName
🟢	LambdaParameterName
🟢	LocalFinalVariableName
🟢	LocalVariableName
🟢	MemberName
🟢	MethodName
🟢	MethodTypeParameterName
🔴	PackageName	Rename package
🟢	ParameterName
🟢	PatternVariableName
🟢	RecordComponentName
🟢	RecordTypeParameterName
🟢	StaticVariableName
🟢	TypeName

Regexp

Status	Check	Coverage Notes
🔴	Regexp	Context-dependent pattern matching
🔴	RegexpMultiline	Context-dependent pattern fixes
🔴	RegexpOnFilename	Rename files
🔴	RegexpSingleline	Context-dependent line fixes
🔴	RegexpSinglelineJava	Context-dependent Java line fixes

Size Violations

Status	Check	Coverage Notes
🔴	AnonInnerLength	Requires refactoring to named classes
🔴	ExecutableStatementCount	Requires method decomposition
🔴	FileLength	Requires file splitting
🔴	LambdaBodyLength	Extract lambda to method
🔴	LineLength	Requires line breaking decisions
🔴	MethodCount	Requires class decomposition
🔴	MethodLength	Requires method decomposition
🔴	OuterTypeNumber	Split types into separate files
🔴	ParameterNumber	Reduce parameter count
🔴	RecordComponentNumber	Reduce record components

Whitespace

Status	Check	Coverage Notes
🟢	ArrayBracketNoWhitespace
🔵	EmptyForInitializerPad
🔵	EmptyForIteratorPad
🟢	EmptyLineSeparator
🟢	FileTabCharacter
🟢	GenericWhitespace
🟢	MethodParamPad
🔴	NoLineWrap	Requires line unwrapping decisions
🔵	NoWhitespaceAfter
🟢	NoWhitespaceBefore
🟢	NoWhitespaceBeforeCaseDefaultColon
🟢	OperatorWrap
🟢	ParenPad
🟢	SeparatorWrap
🟢	SingleSpaceSeparator
🟢	TypeBodyPadding
🟢	TypecastParenPad
🟢	WhitespaceAfter
🟢	WhitespaceAround
🟢	WhitespaceBeforeEmptyBody