.checkstyle.xml

<?xml version="1.0"?>
<!DOCTYPE module PUBLIC
        "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
        "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">
<!--
 In order to be compatible with CodeClimate, we have to stay in sync with the version of Checkstyle that they are using.
 This is currently: 8.39. Check the links below to get up-to-date version information.
 https://docs.codeclimate.com/docs/checkstyle
 https://github.com/codeclimate/codeclimate-checkstyle/blob/master/bin/install-checkstyle.sh
-->

<module name="Checker">
    <property name="charset" value="UTF-8" />
    <property name="severity" value="warning" />
    <property name="fileExtensions" value="java" />

    <module name="SuppressWarningsFilter" />

    <module name="LineLength">
        <property name="max" value="120" />
        <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://" />
    </module>

    <module name="TreeWalker">
        <module name="SuppressWarningsHolder" />
        <module name="SuppressionCommentFilter">
            <property name="offCommentFormat" value="CHECKSTYLE:OFF" />
            <property name="onCommentFormat" value="CHECKSTYLE:ON" />
        </module>

        <!-- The rules are kept by the groups defined in https://checkstyle.org/checks.html
             the checks are held alphabetically per group -->

        <!-- Annotations -->
        <module name="AnnotationLocation">
            <property name="tokens" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF" />
        </module>
        <module name="AnnotationLocation">
            <property name="tokens" value="VARIABLE_DEF" />
            <property name="allowSamelineMultipleAnnotations" value="true" />
        </module>
        <module name="AnnotationUseStyle" />
        <module name="MissingDeprecated" />

        <!-- Block checks -->
        <module name="AvoidNestedBlocks" />
        <module name="EmptyBlock">
            <property name="option" value="TEXT" />
            <property name="tokens" value="LITERAL_WHILE, LITERAL_TRY, LITERAL_FINALLY, LITERAL_DO, LITERAL_IF, LITERAL_ELSE, LITERAL_FOR, INSTANCE_INIT, STATIC_INIT, LITERAL_SWITCH, LITERAL_SYNCHRONIZED, LITERAL_CASE, LITERAL_DEFAULT" />
        </module>
        <module name="EmptyCatchBlock">
            <property name="exceptionVariableName" value="ignore|ignored" />
        </module>
        <module name="LeftCurly" />
        <module name="NeedBraces" />
        <module name="RightCurly">
            <property name="option" value="same" />
            <property name="tokens" value="LITERAL_TRY, LITERAL_CATCH, LITERAL_IF, LITERAL_ELSE, LITERAL_FOR, LITERAL_DO" />
        </module>
        <module name="RightCurly">
            <property name="option" value="alone" />
            <property name="tokens" value="LITERAL_FINALLY, CLASS_DEF, METHOD_DEF, CTOR_DEF, LITERAL_WHILE, STATIC_INIT, INSTANCE_INIT, ANNOTATION_DEF, ENUM_DEF, INTERFACE_DEF, RECORD_DEF, COMPACT_CTOR_DEF" />
        </module>

        <!-- Class design -->
        <module name="FinalClass" />
        <module name="HideUtilityClassConstructor" />
        <module name="InnerTypeLast" />
        <module name="InterfaceIsType" />
        <module name="MutableException" />
        <module name="OneTopLevelClass" />
        <module name="VisibilityModifier" />

        <!-- Coding -->
        <module name="AvoidDoubleBraceInitialization" />
        <module name="AvoidNoArgumentSuperConstructorCall" />
        <module name="CovariantEquals" />
        <module name="DeclarationOrder" />
        <module name="DefaultComesLast" />
        <module name="EmptyStatement" />
        <module name="EqualsAvoidNull" />
        <module name="EqualsHashCode" />
        <module name="FallThrough" />
        <module name="IllegalCatch" />
        <module name="IllegalInstantiation">
            <property name="classes" value="java.lang.Boolean, java.lang.Integer, java.lang.Long, java.lang.String"/>
        </module>
        <module name="IllegalThrows" />
        <module name="IllegalToken" />
        <module name="IllegalTokenText">
            <property name="tokens" value="STRING_LITERAL, CHAR_LITERAL" />
            <property name="format" value="\\u00(08|09|0(a|A)|0(c|C)|0(d|D)|22|27|5(C|c))|\\(0(10|11|12|14|15|42|47)|134)" />
            <property name="message" value="Avoid using corresponding octal or Unicode escape." />
        </module>
        <module name="IllegalType" />
        <module name="InnerAssignment" />
        <module name="MagicNumber" />
        <module name="MissingSwitchDefault" />
        <module name="ModifiedControlVariable" />
        <module name="MultipleVariableDeclarations" />
        <module name="NestedForDepth" />
        <module name="NestedIfDepth" />
        <module name="NestedTryDepth" />
        <module name="NoArrayTrailingComma" />
        <module name="NoClone" />
        <module name="NoEnumTrailingComma" />
        <module name="NoFinalizer" />
        <module name="OneStatementPerLine" />
        <module name="OverloadMethodsDeclarationOrder" />
        <module name="PackageDeclaration" />
        <module name="ParameterAssignment" />
        <module name="SimplifyBooleanExpression" />
        <module name="SimplifyBooleanReturn" />
        <module name="StringLiteralEquality" />
        <module name="UnnecessaryParentheses" />
        <module name="UnnecessarySemicolonAfterOuterTypeDeclaration" />
        <module name="UnnecessarySemicolonAfterTypeMemberDeclaration" />
        <module name="UnnecessarySemicolonInEnumeration" />
        <module name="UnnecessarySemicolonInTryWithResources" />
        <!-- Checkstyle 9.3: <module name="UnusedLocalVariable" /> -->
        <module name="VariableDeclarationUsageDistance" />

        <!-- Headers -->

        <!-- Imports -->
        <module name="AvoidStarImport" />
        <module name="RedundantImport" />
        <module name="UnusedImports" />

        <!-- Javadoc comments -->
        <module name="AtclauseOrder">
            <property name="tagOrder" value="@param, @return, @throws, @see, @deprecated" />
            <property name="target" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF, VARIABLE_DEF" />
        </module>
        <module name="InvalidJavadocPosition" />
        <module name="JavadocBlockTagLocation" />
        <module name="JavadocContentLocation" />
        <module name="JavadocMethod">
            <property name="scope" value="package" />
            <property name="tokens" value="METHOD_DEF, ANNOTATION_FIELD_DEF" />
        </module>
        <module name="JavadocMissingLeadingAsterisk" />
        <module name="JavadocMissingWhitespaceAfterAsterisk" />
        <module name="JavadocStyle" />
        <module name="JavadocTagContinuationIndentation" />
        <module name="JavadocType" />
        <module name="JavadocVariable">
            <property name="scope" value="package" />
        </module>
        <module name="MissingJavadocMethod">
            <property name="scope" value="package" />
            <property name="minLineCount" value="4" />
            <property name="allowedAnnotations" value="Override, Test" />
            <property name="tokens" value="METHOD_DEF, ANNOTATION_FIELD_DEF" />
        </module>
        <module name="MissingJavadocType">
            <property name="scope" value="package" />
        </module>
        <module name="NonEmptyAtclauseDescription" />
        <module name="RequireEmptyLineBeforeBlockTagGroup" />
        <module name="SingleLineJavadoc">
            <property name="ignoredTags" value="@return" />
        </module>

        <!-- Metrics -->
        <module name="BooleanExpressionComplexity">
            <property name="max" value="5" />
        </module>
        <module name="CyclomaticComplexity">
            <property name="max" value="15" />
        </module>
        <module name="JavaNCSS">
            <property name="methodMaximum" value="40" />
            <property name="classMaximum" value="1000" />
        </module>

        <!-- Miscellaneous -->
        <module name="ArrayTypeStyle" />
        <module name="AvoidEscapedUnicodeCharacters">
            <property name="allowEscapesForControlCharacters" value="true" />
            <property name="allowByTailComment" value="true" />
            <property name="allowNonPrintableEscapes" value="true" />
        </module>
        <module name="CommentsIndentation" />
        <module name="Indentation" />
        <module name="NoCodeInFile" />
        <module name="OuterTypeFilename" />
        <module name="TodoComment">
            <property name="format" value="(?i)(TODO|FIXME)" />
        </module>
        <module name="UpperEll" />

        <!-- Modifiers -->
        <module name="ModifierOrder" />
        <module name="RedundantModifier" />

        <!-- Naming conventions -->
        <module name="AbbreviationAsWordInName">
            <property name="ignoreFinal" value="false" />
            <property name="ignoreStatic" value="false" />
            <property name="allowedAbbreviationLength" value="0" />
        </module>
        <module name="CatchParameterName" />
        <module name="ClassTypeParameterName" />
        <module name="ConstantName" />
        <module name="InterfaceTypeParameterName" />
        <module name="LambdaParameterName" />
        <module name="LocalFinalVariableName" />
        <module name="LocalVariableName" />
        <module name="MemberName" />
        <module name="MethodName" />
        <module name="MethodTypeParameterName" />
        <module name="PackageName">
            <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$" />
        </module>
        <module name="ParameterName" />
        <module name="StaticVariableName" />
        <module name="TypeName" />

        <!-- Regexp -->

        <!-- Size violations -->

        <!-- Whitespace -->
        <module name="EmptyLineSeparator">
            <property name="allowNoEmptyLineBetweenFields" value="true" />
        </module>
        <module name="GenericWhitespace" />
        <module name="MethodParamPad" />
        <module name="NoLineWrap" />
        <module name="NoWhitespaceAfter">
            <!-- Override to exclude ARRAY_INIT and to add LITERAL_SYNCHRONIZED, METHOD_REF -->
            <property name="tokens" value="AT, INC, DEC, UNARY_MINUS, UNARY_PLUS, BNOT, LNOT, DOT, ARRAY_DECLARATOR, INDEX_OP, LITERAL_SYNCHRONIZED, METHOD_REF" />
        </module>
        <module name="NoWhitespaceBefore">
            <!-- Override to exclude ELLIPSIS and to add METHOD_REF -->
            <property name="tokens" value="COMMA, SEMI, POST_INC, POST_DEC, LABELED_STAT, METHOD_REF" />
        </module>
        <!-- Checkstyle 8.45: <module name="NoWhitespaceBeforeCaseDefaultColon" /> -->
        <module name="OperatorWrap" />
        <module name="ParenPad" />
        <module name="SeparatorWrap">
            <property name="tokens" value="DOT" />
            <property name="option" value="nl" />
        </module>
        <module name="SeparatorWrap">
            <property name="tokens" value="COMMA" />
            <property name="option" value="EOL" />
        </module>
        <module name="SingleSpaceSeparator" />
        <module name="TypecastParenPad" />
        <module name="WhitespaceAfter" />
        <module name="WhitespaceAround" />
    </module>

    <module name="FileTabCharacter" />
    <module name="NewlineAtEndOfFile" />
</module>