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
🟢	Full Coverage – Complete auto-fix capability for all violation scenarios
🟡	Partial Coverage – Auto-fix available for some violation scenarios
🔴	Won't Be Covered – Auto-fix not feasible or not planned

Annotations

Status	Check	Recipe	Coverage Notes
🟢	AnnotationLocation	TBD
🟢	AnnotationOnSameLine	TBD
🔴	AnnotationUseStyle		Standardize annotation syntax
🟢	MissingDeprecated	TBD
🟢	MissingOverride	TBD
🟢	PackageAnnotation	TBD
🔴	SuppressWarnings		Remove inappropriate suppressions

Block Checks

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

Class Design

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

Coding

Status	Check	Recipe	Coverage Notes
🟢	ArrayTrailingComma	TBD
🔴	AvoidDoubleBraceInitialization		Requires refactoring initialization logic
🔴	AvoidInlineConditionals		Requires extracting to if-else statements
🟢	AvoidNoArgumentSuperConstructorCall	TBD
🟢	ConstructorsDeclarationGrouping	TBD
🔴	CovariantEquals		Requires implementing proper equals(Object)
🟢	DeclarationOrder	TBD
🟢	DefaultComesLast	TBD
🟢	EmptyStatement	EmptyStatement
🟢	EqualsAvoidNull	TBD
🔴	EqualsHashCode		Implement proper equals/hashCode pair
🟢	ExplicitInitialization	TBD
🔴	FallThrough		Add break statements or intentional comments
🟢	FinalLocalVariable	FinalLocalVariable
🔴	HiddenField		Rename variables or use this. prefix
🔴	IllegalCatch		Change catch block exception types
🔴	IllegalInstantiation		Replace with factory methods
🔴	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	TBD
🟢	MissingSwitchDefault	TBD
🔴	ModifiedControlVariable		Restructure loop logic
🔴	MultipleStringLiterals		Extract to constants
🟢	MultipleVariableDeclarations	TBD
🔴	NestedForDepth		Requires loop restructuring
🔴	NestedIfDepth		Requires conditional restructuring
🔴	NestedTryDepth		Requires exception handling restructuring
🟢	NoArrayTrailingComma	TBD
🔴	NoClone		Remove clone() method
🟢	NoEnumTrailingComma	TBD
🔴	NoFinalizer

Headers

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

Imports

Status	Check	Recipe	Coverage Notes
🟢	AvoidStarImport	TBD
🟢	AvoidStaticImport	TBD
🟢	CustomImportOrder	TBD
🔴	IllegalImport		Replace with allowed imports
🔴	ImportControl		Restructure imports per rules
🟢	ImportOrder	TBD
🟢	RedundantImport	RedundantImport
🟢	UnusedImports	TBD

Javadoc Comments

Status	Check	Recipe	Coverage Notes
🟢	AtclauseOrder	TBD
🟢	InvalidJavadocPosition	TBD
🟢	JavadocBlockTagLocation	TBD
🟢	JavadocContentLocation	TBD
🟢	JavadocLeadingAsteriskAlign	TBD
🔴	JavadocMethod		Add/fix method documentation
🟢	JavadocMissingLeadingAsterisk	TBD
🟢	JavadocMissingWhitespaceAfterAsterisk	TBD
🔴	JavadocPackage		Create package-info.java
🟢	JavadocParagraph	TBD
🟢	JavadocStyle	TBD
🟢	JavadocTagContinuationIndentation	TBD
🔴	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
🟢	RequireEmptyLineBeforeBlockTagGroup	TBD
🟢	SingleLineJavadoc	TBD
🔴	SummaryJavadoc		Rewrite summary sentences
🔴	WriteTag		Add/fix custom Javadoc tags

Metrics

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

Modifiers

Status	Check	Recipe	Coverage Notes
🟢	ClassMemberImpliedModifier	TBD
🟢	InterfaceMemberImpliedModifier	TBD
🟢	ModifierOrder	TBD
🟢	RedundantModifier	TBD

Naming Conventions

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

Regexp

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