checkstyle.xml

<?xml version="1.0"?>
<!DOCTYPE module PUBLIC
    "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
    "https://checkstyle.org/dtds/configuration_1_3.dtd">
<!--
    Checkstyle configuration
-->
<module name="Checker">

    <!-- https://checkstyle.org/property_types.html -->
    <property name="charset" value="UTF-8"/>
    <property name="fileExtensions" value="java, properties, xml"/>


    <!-- https://checkstyle.org/config_filefilters.html -->
    <!--     Excludes all 'module-info.java' files      -->
    <module name="BeforeExecutionExclusionFileFilter">
        <property name="fileNamePattern" value="module\-info\.java$"/>
    </module>


    <!-- https://checkstyle.org/config_javadoc.html#JavadocPackage     -->
    <!-- Checks that a package-info.java file exists for each package. -->
    <!-- <module name="JavadocPackage"/> -->


    <!-- https://checkstyle.org/config_misc.html#NewlineAtEndOfFile -->
    <!--       Checks whether files end with a new line.            -->
    <module name="NewlineAtEndOfFile"/>


    <!-- https://checkstyle.org/config_misc.html#Translation -->
    <!--   Checks that property files contain the same keys. -->
    <module name="Translation"/>


    <!-- https://checkstyle.org/config_misc.html#UniqueProperties -->
    <!--             Check for duplicate properties.              -->
    <module name="UniqueProperties"/>


    <!-- https://checkstyle.org/config_sizes.html -->
    <!--      Checks for Size Violations.         -->
    <module name="FileLength"/>
    <module name="LineLength">
        <property name="max" value="120"/>
        <property name="fileExtensions" value="java"/>
        <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
    </module>


    <!-- https://checkstyle.org/config_whitespace.html -->
    <!--            Checks for tabs                    -->
    <module name="FileTabCharacter"/>


    <!-- https://checkstyle.org/config_misc.html -->
    <!--      Check for trailing spaces.        -->
    <module name="RegexpSingleline">
        <property name="format" value="\s+$"/>
        <property name="minimum" value="0"/>
        <property name="maximum" value="0"/>
        <property name="message" value="Line has trailing spaces."/>
    </module>


    <!-- https://checkstyle.org/config_filters.html -->
    <!--  Suppression with comments/annotation .    -->
    <module name="SuppressWithPlainTextCommentFilter"/>
    <module name="SuppressWarningsFilter"/>


    <module name="TreeWalker">
        <!-- https://checkstyle.org/config_javadoc.html -->
        <!--         Checks for Javadoc comments.       -->
        <!-- <module name="AtclauseOrder"/> -->
        <!-- <module name="InvalidJavadocPosition"/> -->
        <!--<module name="JavadocContentLocationCheck"/>-->
        <!-- <module name="JavadocMethod"/> -->
        <module name="JavadocMissingLeadingAsteriskCheck"/>
        <module name="JavadocMissingWhitespaceAfterAsterisk"/>
        <!-- <module name="JavadocParagraph"/> -->
        <module name="JavadocStyle">
            <property name="checkFirstSentence" value="false"/>
            <property name="checkEmptyJavadoc" value="true"/>
            <property name="tokens"
                      value="ANNOTATION_DEF, ANNOTATION_FIELD_DEF, CLASS_DEF, CTOR_DEF, ENUM_CONSTANT_DEF, ENUM_DEF, INTERFACE_DEF, METHOD_DEF, VARIABLE_DEF"/>
        </module>
        <!--<module name="JavadocTagContinuationIndentation"/>-->
        <!--<module name="JavadocType">-->
        <!--    <property name="scope" value="public"/>-->
        <!--</module>-->
        <!-- <module name="JavadocVariable"/> -->
        <!-- <module name="MissingJavadocMethod"/> -->
        <!-- <module name="MissingJavadocPackage"/> -->
        <!-- <module name="MissingJavadocType"/> -->
        <module name="NonEmptyAtclauseDescription"/>
        <module name="SingleLineJavadoc"/>
        <!-- <module name="SummaryJavadoc"/> -->
        <!-- <module name="WriteTag"/> -->


        <!-- https://checkstyle.org/config_annotation.html -->
        <!--              Annotations                      -->
        <!-- <module name="AnnotationLocation">-->
        <!--  <property name="id" value="AnnotationLocationMostCases"/>-->
        <!--  <property name="tokens" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF"/>-->
        <!-- </module>-->
        <!-- <module name="AnnotationLocation">-->
        <!--  <property name="id" value="AnnotationLocationVariables"/>-->
        <!--  <property name="tokens" value="VARIABLE_DEF"/>-->
        <!--  <property name="allowSamelineMultipleAnnotations" value="true"/>-->
        <!-- </module>-->
        <!-- <module name="AnnotationOnSameLine"/> -->
        <!-- <module name="AnnotationUseStyle"/> -->
        <!-- <module name="MissingDeprecated"/> -->
        <module name="MissingOverride"/>
        <!-- <module name="PackageAnnotation"/> -->


        <!-- https://checkstyle.org/config_naming.html -->
        <!--      Checks for Naming Conventions.       -->
        <!-- <module name="AbbreviationAsWordInName"/> -->
        <!-- <module name="AbstractClassName"/> -->
        <module name="CatchParameterName"/>
        <module name="ClassTypeParameterName"/>
        <module name="ConstantName"/>
        <module name="IllegalIdentifierName"/>
        <module name="InterfaceTypeParameterName"/>
        <module name="LambdaParameterName"/>
        <module name="LocalVariableName"/>
        <module name="MemberName"/>
        <module name="MethodName"/>
        <module name="MethodTypeParameterName"/>
        <module name="PackageName"/>
        <module name="ParameterName"/>
        <module name="PatternVariableName"/>
        <module name="RecordTypeParameterName"/>
        <module name="RecordComponentName"/>
        <module name="StaticVariableName"/>
        <module name="TypeName"/>


        <!-- https://checkstyle.org/config_imports.html -->
        <!--            Checks for imports              -->
        <module name="AvoidStarImport"/>
        <!-- <module name="AvoidStaticImport"/> -->
        <!-- <module name="CustomImportOrder"/> -->
        <module name="IllegalImport"/> <!-- defaults to sun.* packages -->
        <!-- <module name="ImportControl"/> -->
        <module name="ImportOrder">
            <property name="option" value="under"/>
            <property name="sortStaticImportsAlphabetically" value="true"/>
        </module>
        <module name="RedundantImport"/>
        <module name="UnusedImports"/>


        <!-- https://checkstyle.org/config_sizes.html -->
        <!--      Checks for Size Violations.         -->
        <module name="AnonInnerLength">
            <property name="max" value="40"/>
        </module>
        <!-- <module name="ExecutableStatementCount"/> -->
        <module name="LambdaBodyLength">
            <property name="max" value="40"/>
        </module>
        <!-- <module name="MethodCount"/> -->
        <module name="MethodLength"/>
        <module name="OuterTypeNumber"/>
        <module name="ParameterNumber"/>
        <module name="RecordComponentNumber"/>


        <!-- https://checkstyle.org/config_whitespace.html -->
        <!--          Checks for whitespace                -->
        <!-- <module name="EmptyForInitializerPad"/> -->
        <module name="EmptyForIteratorPad"/>
        <module name="EmptyLineSeparator">
            <property name="allowNoEmptyLineBetweenFields" value="true"/>
        </module>
        <module name="GenericWhitespace"/>
        <module name="MethodParamPad"/>
        <module name="NoLineWrap"/>
        <module name="NoWhitespaceAfter"/>
        <module name="NoWhitespaceBefore"/>
        <module name="NoWhitespaceBeforeCaseDefaultColon"/>
        <module name="OperatorWrap"/>
        <module name="ParenPad"/>
        <module name="SeparatorWrap">
            <property name="id" value="SeparatorWrapDot"/>
            <property name="tokens" value="DOT"/>
            <property name="option" value="nl"/>
        </module>
        <module name="SeparatorWrap">
            <property name="id" value="SeparatorWrapComma"/>
            <property name="tokens" value="COMMA"/>
            <property name="option" value="EOL"/>
        </module>
        <module name="SeparatorWrap">
            <property name="id" value="SeparatorWrapEllipsis"/>
            <property name="tokens" value="ELLIPSIS"/>
            <property name="option" value="EOL"/>
        </module>
        <module name="SeparatorWrap">
            <property name="id" value="SeparatorWrapArrayDeclarator"/>
            <property name="tokens" value="ARRAY_DECLARATOR"/>
            <property name="option" value="EOL"/>
        </module>
        <module name="SeparatorWrap">
            <property name="id" value="SeparatorWrapMethodRef"/>
            <property name="tokens" value="METHOD_REF"/>
            <property name="option" value="nl"/>
        </module>
        <!-- <module name="SingleSpaceSeparator"/> -->
        <module name="TypecastParenPad"/>
        <module name="WhitespaceAfter"/>
        <module name="WhitespaceAround">
            <property name="allowEmptyConstructors" value="true"/>
            <property name="allowEmptyLambdas" value="true"/>
            <property name="allowEmptyMethods" value="true"/>
            <property name="allowEmptyTypes" value="true"/>
            <property name="allowEmptyLoops" value="true"/>
            <message key="ws.notFollowed"
                     value="WhitespaceAround: ''{0}'' is not followed by whitespace. Empty blocks may only be represented as '{}' when it's ctor, method, type, lambda or loop"/>
            <message key="ws.notPreceded"
                     value="WhitespaceAround: ''{0}'' is not preceded with whitespace."/>
        </module>


        <!-- https://checkstyle.org/config_modifier.html -->
        <!--             Modifier Checks                 -->
        <!-- <module name="ClassMemberImpliedModifier"/> -->
        <!-- <module name="InterfaceMemberImpliedModifier"/> -->
        <!--<module name="ModifierOrder"/>-->
        <module name="RedundantModifier"/>


        <!-- https://checkstyle.org/config_blocks.html -->
        <!-- Checks for blocks. You know, those {}'s   -->
        <module name="AvoidNestedBlocks">
            <property name="allowInSwitchCase" value="true"/>
        </module>
        <module name="EmptyBlock">
            <property name="option" value="TEXT"/>
            <property name="tokens" value="LITERAL_TRY, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_SWITCH"/>
        </module>
        <module name="LeftCurly"/>
        <module name="NeedBraces"/>
        <module name="RightCurly"/>


        <!-- https://checkstyle.org/config_coding.html -->
        <!--      Checks for common coding problems    -->
        <!-- <module name="ArrayTrailingComma"/> -->
        <!-- <module name="AvoidDoubleBraceInitialization"/> -->
        <!-- <module name="AvoidInlineConditionals"/> -->
        <module name="AvoidNoArgumentSuperConstructorCall"/>
        <module name="ConstructorsDeclarationGrouping"/>
        <module name="CovariantEquals"/>
        <!--<module name="DeclarationOrder"/>-->
        <module name="DefaultComesLast"/>
        <module name="EmptyStatement"/>
        <!-- <module name="EqualsAvoidNull"/> -->
        <module name="EqualsHashCode"/>
        <!-- <module name="ExplicitInitialization"/> -->
        <module name="FallThrough"/>
        <!-- <module name="FinalLocalVariable"/> -->
        <module name="HiddenField">
            <property name="tokens" value="VARIABLE_DEF"/>
        </module>
        <!-- <module name="IllegalCatch"/> -->
        <module name="IllegalInstantiation">
            <property name="classes" value="java.lang.Boolean"/>
        </module>
        <!-- <module name="IllegalThrows"/> -->
        <!-- <module name="IllegalToken"/> -->
        <!-- <module name="IllegalTokenText"/> -->
        <!-- <module name="IllegalType"/> -->
        <module name="InnerAssignment"/>
        <module name="MagicNumber">
            <property name="ignoreHashCodeMethod" value="true"/>
            <property name="ignoreAnnotation" value="true"/>
            <message key="magic.number"
                     value="Most likely the value ''{0}'' is a configuration one. You should move it to configuration file instead of source code."/>
        </module>
        <!-- <module name="MissingCtor"/> -->
        <module name="MissingSwitchDefault"/>
        <module name="ModifiedControlVariable"/>
        <module name="MultipleStringLiterals">
            <!-- Allow zero-length and 1-character strings -->
            <property name="ignoreStringsRegexp" value='^(("")|(".")|("..")|("..>"))$'/>
        </module>
        <module name="MultipleVariableDeclarations"/>
        <module name="NestedForDepth">
            <property name="max" value="2"/>
        </module>
        <module name="NestedIfDepth">
            <property name="max" value="2"/>
        </module>
        <module name="NestedTryDepth">
            <property name="max" value="2"/>
        </module>
        <!--<module name="NoArrayTrailingComma"/>-->
        <!--<module name="NoEnumTrailingComma"/>-->
        <module name="NoClone"/>
        <module name="NoFinalizer"/>
        <module name="OneStatementPerLine"/>
        <!--<module name="OverloadMethodsDeclarationOrder"/>-->
        <module name="PackageDeclaration"/>
        <module name="ParameterAssignment"/>
        <!-- <module name="RequireThis"/> -->
        <module name="ReturnCount">
            <property name="max" value="4"/>
        </module>
        <module name="SimplifyBooleanExpression"/>
        <module name="SimplifyBooleanReturn"/>
        <module name="StringLiteralEquality"/>
        <module name="SuperClone"/>
        <module name="SuperFinalize"/>
        <!-- <module name="UnnecessaryParentheses"/> -->
        <!-- <module name="UnnecessarySemicolonInEnumeration"/> -->
        <!-- <module name="UnnecessarySemicolonInTryWithResources"/> -->
        <!-- <module name="UnnecessarySemicolonAfterOuterTypeDeclaration"/> -->
        <!-- <module name="UnusedLocalVariable"/> -->
        <!-- <module name="VariableDeclarationUsageDistance"/> -->

        <!-- https://checkstyle.org/config_design.html -->
        <!--       Checks for class design             -->
        <!-- <module name="DesignForExtension"/> -->
        <module name="FinalClass">
            <property name="severity" value="warning"/>
            <message key="final.class"
                     value="Private ctor in non-final class. Inspect the code and make sure it's intended."/>
        </module>
        <module name="HideUtilityClassConstructor"/>
        <module name="SuppressionXpathSingleFilter">
            <property name="checks" value="HideUtilityClassConstructor"/>
            <property name="query" value="//*[MODIFIERS//*[@text = 'UtilityClass' or @text='NoArgsConstructor' or @text = 'SpringBootApplication']]/descendant-or-self::node()"/>
        </module>
        <module name="InnerTypeLast"/>
        <!--<module name="InterfaceIsType"/>-->
        <module name="MutableException"/>
        <module name="OneTopLevelClass"/>
        <!-- <module name="ThrowsCount"/> -->
        <!-- <module name="VisibilityModifier"/> -->


        <!-- Miscellaneous other checks.                   -->
        <!-- https://checkstyle.org/config_misc.html -->
        <module name="ArrayTypeStyle"/>
        <!-- <module name="AvoidEscapedUnicodeCharacters"/> -->
        <!-- <module name="CommentsIndentation"/> -->
        <!-- <module name="DescendantToken"/> -->
        <!-- <module name="FinalParameters"/> -->
        <module name="NoCodeInFile"/>

        <!-- https://github.com/checkstyle/checkstyle/issues/3122 -->
        <!-- https://github.com/checkstyle/checkstyle/issues/3342 -->
        <!-- this module is broken for a long time, I'm not sure if we should use it -->
        <!-- <module name="Indentation"/> -->

        <!-- <module name="OrderedProperties"/> -->
        <module name="OuterTypeFilename"/>
        <!-- <module name="TodoComment" /> -->
        <!-- <module name="TrailingComment"/> -->
        <module name="UncommentedMain">
            <property name="excludedClasses" value="Application|Main"/>
        </module>
        <module name="UpperEll"/>


        <!-- https://checkstyle.org/config_metrics.html -->
        <!--         Checks for Code Metrics.           -->
        <!-- <module name="BooleanExpressionComplexity"/> -->
        <!-- <module name="ClassDataAbstractionCoupling"/> -->
        <!-- <module name="ClassFanOutComplexity"/> -->
        <module name="CyclomaticComplexity">
            <property name="max" value="16"/>
        </module>
        <!-- <module name="JavaNCSS"/> -->
        <!-- <module name="NPathComplexity"/> -->


        <!-- https://checkstyle.org/config_regexp.html -->
        <!--      Checks for forbidden code.           -->
        <module name="RegexpSinglelineJava">
            <property name="format" value="\.printStackTrace"/>
            <property name="ignoreComments" value="true"/>
            <property name="message" value="Using printStackTrace is a bad practice. Use a logger instead."/>
        </module>
        <module name="RegexpSinglelineJava">
            <property name="format" value="System\.out\.print"/>
            <property name="ignoreComments" value="true"/>
            <property name="message" value="Using System.out for logging is a bad practice. Use a logger instead."/>
        </module>
        <module name="RegexpSinglelineJava">
            <property name="format" value="javax\.annotation\.Nonnull|javax\.annotation\.Nullable|javax\.annotation\.ParametersAreNonnullByDefault|javax\.annotation\.ParametersAreNullableByDefault|org\.springframework\.lang\.Nullable|org\.springframework\.lang\.NonNull|org\.springframework\.lang\.NonNullApi|org\.springframework\.lang\.NonNullFields|edu\.umd\.cs\.findbugs\.annotations\.Nullable|edu\.umd\.cs\.findbugs\.annotations\.NonNull"/>
            <property name="ignoreComments" value="true"/>
            <property name="message" value="Use org.jspecify.* for nullability."/>
        </module>


        <!-- https://checkstyle.org/config_filters.html -->
        <!-- Comments/annotation suppression.           -->
        <module name="SuppressionCommentFilter"/>
        <!-- <module name="SuppressWarnings"/> -->
        <module name="SuppressWarningsHolder"/>
        <module name="SuppressWithNearbyCommentFilter"/>

    </module>

</module>