src/resources/checkstyle.xml

<?xml version="1.0"?>
<!--
  ~ Licensed to the Apache Software Foundation (ASF) under one or more
  ~ contributor license agreements.  See the NOTICE file distributed with
  ~ this work for additional information regarding copyright ownership.
  ~ The ASF licenses this file to You under the Apache License, Version 2.0
  ~ (the "License"); you may not use this file except in compliance with
  ~ the License.  You may obtain a copy of the License at
  ~
  ~     http://www.apache.org/licenses/LICENSE-2.0
  ~
  ~ Unless required by applicable law or agreed to in writing, software
  ~ distributed under the License is distributed on an "AS IS" BASIS,
  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  ~ See the License for the specific language governing permissions and
  ~ limitations under the License.
  -->

<!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.3//EN" "http://checkstyle.sourceforge.net/dtds/configuration_1_3.dtd">
<module name="Checker">
    <property name="charset" value="UTF-8" />
    <property name="severity" value="warning" />
    <property name="fileExtensions" value="java, properties, xml" />
    <module name="Header">
        <property name="fileExtensions" value="java" />
    </module>
    <module name="FileTabCharacter">
        <property name="eachLine" value="true" />
    </module>
    <module name="FileLength" />
    <module name="NewlineAtEndOfFile">
        <property name="lineSeparator" value="lf" />
    </module>
    <module name="Translation" />
    <module name="UniqueProperties" />
    <module name="SeverityMatchFilter" />
    
    <module name="TreeWalker">
        
        <!-- Naming Conventions -->
        <module name="PackageName">
            <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$" />
        </module>
        <module name="TypeName" />
        <module name="MethodName" />
        <module name="InterfaceTypeParameterName" />
        <module name="ClassTypeParameterName" />
        <module name="MethodTypeParameterName" />
        <module name="ConstantName" />
        <module name="StaticVariableName" />
        <module name="MemberName" />
        <module name="LocalVariableName" />
        <module name="LocalFinalVariableName" />
        <module name="ParameterName" />
        <module name="CatchParameterName" />
        <module name="AbbreviationAsWordInName">
            <property name="allowedAbbreviationLength" value="6" />
        </module>
        
        <!-- Size Violations -->
        <module name="AnonInnerLength" />
        <module name="MethodLength" />
        <module name="LineLength">
            <property name="max" value="200" />
        </module>
        <module name="MethodCount" />
        <module name="ExecutableStatementCount">
            <property name="max" value="50" />
        </module>
        <module name="OuterTypeNumber" />
        <module name="ParameterNumber" />
        
        <!-- Whitespace -->
        <module name="EmptyForInitializerPad" />
        <module name="EmptyForIteratorPad" />
        <module name="MethodParamPad" />
        <module name="ParenPad" />
        <module name="TypecastParenPad" />
        <module name="NoLineWrap" />
        <module name="OperatorWrap" />
        <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="GenericWhitespace" />
        <module name="NoWhitespaceBefore" />
        <module name="NoWhitespaceAfter" />
        <module name="WhitespaceAround" />
        <module name="WhitespaceAfter" />
        <module name="SingleSpaceSeparator" />
        <module name="EmptyLineSeparator">
            <property name="allowMultipleEmptyLines" value="false" />
            <property name="allowMultipleEmptyLinesInsideClassMembers" value="false" />
        </module>
        
        <!-- Imports -->
        <module name="AvoidStarImport" />
        <module name="AvoidStaticImport">
            <property name="excludes" value="org.junit.Assert.*,org.hamcrest.Matchers.*,org.hamcrest.CoreMatchers.*,org.mockito.Mockito.*,org.mockito.ArgumentMatchers.*" />
        </module>
        <module name="IllegalImport" />
        <module name="RedundantImport" />
        <module name="UnusedImports" />
        <module name="CustomImportOrder" />
        
        <!-- 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="AnnotationUseStyle" />
        <module name="MissingOverride" />
        <module name="SuppressWarnings" />
        <module name="MissingDeprecated" />
        <module name="SuppressWarningsHolder" />
        
        <!-- Modifiers -->
        <module name="ModifierOrder" />
        <module name="RedundantModifier" />
        
        <!-- Coding -->
        <module name="ArrayTrailingComma" />
        <module name="CovariantEquals" />
        <module name="DefaultComesLast" />
        <module name="DeclarationOrder" />
        <module name="EmptyStatement" />
        <module name="EqualsAvoidNull" />
        <module name="EqualsHashCode" />
        <module name="ExplicitInitialization" />
        <module name="FallThrough" />
        <module name="IllegalInstantiation" />
        <module name="IllegalCatch" />
        <module name="IllegalThrows" />
        <module name="IllegalType">
            <property name="tokens" value="METHOD_DEF,PARAMETER_DEF,VARIABLE_DEF" />
        </module>
        <module name="IllegalTokenText">
            <property name="tokens" value="STRING_LITERAL, CHAR_LITERAL" />
            <property name="format" value="\\u00(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="Consider using special escape sequence instead of octal value or Unicode escaped value." />
        </module>
        <module name="MissingSwitchDefault" />
        <module name="ModifiedControlVariable" />
        <module name="MultipleVariableDeclarations" />
        <module name="NestedForDepth" />
        <module name="NestedIfDepth" />
        <module name="NestedTryDepth" />
        <module name="NoClone" />
        <module name="NoFinalizer" />
        <module name="SuperClone" />
        <module name="SuperFinalize" />
        <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="VariableDeclarationUsageDistance" />
        
        <!-- Block Checks -->
        <module name="EmptyBlock" />
        <module name="EmptyCatchBlock">
            <property name="exceptionVariableName" value="expected|ignore" />
        </module>
        <module name="AvoidNestedBlocks" />
        <module name="NeedBraces" />
        <module name="LeftCurly" />
        <module name="RightCurly" />
        
        <!-- Class Design -->
        <module name="DesignForExtension" />
        <module name="FinalClass" />
        <!-- cannot recognize for lombok @NoArgsConstructor(access = AccessLevel.PRIVATE), just ignore -->
        <!--<module name="HideUtilityClassConstructor"/>-->
        <module name="OneTopLevelClass" />
        <module name="InterfaceIsType" />
        <module name="InnerTypeLast" />
        <module name="VisibilityModifier" />
        <module name="MutableException" />
        <module name="ThrowsCount" />
        
        <!-- Metrics -->
        <module name="BooleanExpressionComplexity" />
        <module name="ClassDataAbstractionCoupling">
            <property name="max" value="10" />
        </module>
        <module name="ClassFanOutComplexity" />
        <module name="CyclomaticComplexity" />
        <module name="NPathComplexity" />
        <module name="JavaNCSS" />
        
        <!-- Miscellaneous -->
        <module name="ArrayTypeStyle" />
        <module name="UpperEll" />
        <module name="AvoidEscapedUnicodeCharacters" />
        <module name="DescendantToken" />
        <module name="FinalParameters" />
        <module name="Indentation" />
        <module name="OuterTypeFilename" />
        <module name="TodoComment" />
        <module name="TrailingComment" />
        <module name="UncommentedMain">
            <property name="excludedClasses" value="\.Bootstrap" />
        </module>
        
        <!-- Javadoc Comments -->
        <module name="AtclauseOrder">
            <property name="tagOrder" value="@param, @return, @throws, @deprecated" />
        </module>
        <module name="NonEmptyAtclauseDescription" />
        <module name="JavadocParagraph" />
        <module name="JavadocStyle" />
        <module name="JavadocTagContinuationIndentation" />
        <module name="SingleLineJavadoc" />
        <module name="SummaryJavadoc" />
        <!--
        <module name="JavadocType">
            <property name="scope" value="public"/>
        </module>
        -->
        <module name="JavadocMethod">
            <property name="scope" value="public" />
            <property name="allowedAnnotations" value="Override, Test, Before, After, BeforeClass, AfterClass, Parameterized, Parameters" />
            <property name="ignoreMethodNamesRegex" value="^assert.*$|^verify.*$" />
            <property name="tokens" value="METHOD_DEF, ANNOTATION_FIELD_DEF" />
        </module>
        
        <!-- Filters -->
        <module name="SuppressionCommentFilter" />
        <module name="SuppressWithNearbyCommentFilter" />
    </module>
</module>