checkstyle.xml

<?xml version="1.0"?>
<!DOCTYPE module PUBLIC
    "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
    "http://checkstyle.sourceforge.net/dtds/configuration_1_3.dtd">

<!--
    Checkstyle configuration that checks the Google coding conventions from Google Java Style
    that can be found at https://google.github.io/styleguide/javaguide.html.
    Checkstyle is very configurable. Be sure to read the documentation at
    http://checkstyle.sf.net (or in your downloaded distribution).
    To completely disable a check, just comment it out or delete it from the file.
    Authors: Max Vetrenko, Ruslan Diachenko, Roman Ivanov.
    References:
    'https://source.android.com/setup/contribute/code-style'
    'https://google.github.io/styleguide/javaguide.html'
    'https://github.com/checkstyle/checkstyle/tree/master/src/main/resources'
 -->

<module name="Checker">
    <module name="SuppressionFilter">
        <property name="file" default="suppressions.xml" value="${checkstyleSuppressionsPath}"/>
    </module>
    <property name="charset" value="UTF-8"/>
    <property name="severity" value="warning"/>
    <!--<property name="localeLanguage" value="en"/>-->
    <property name="fileExtensions" value="java"/>
    <!-- Checks for whitespace                               -->
    <!-- See http://checkstyle.sf.net/config_whitespace.html -->
    <module name="FileTabCharacter">
        <property name="eachLine" value="true"/>
    </module>
    <module name="NewlineAtEndOfFile">
        <property name="severity" value="info"/>
    </module>
    <module name="FileLength">
        <property name="severity" value="info"/>
        <property name="max" value="1500"/>
    </module>

    <module name="TreeWalker">
        <!-- 1. Source File Basic-->
        <module name="OuterTypeFilename"/>
        <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="AvoidEscapedUnicodeCharacters">
            <property name="allowEscapesForControlCharacters" value="true"/>
            <property name="allowByTailComment" value="true"/>
            <property name="allowNonPrintableEscapes" value="true"/>
        </module>


        <!-- 2. Source File Structure -->
        <module name="AvoidStarImport">
            <property name="excludes"
                      value="java.io,java.net,java.lang.Math,org.junit,org.junit.Assert"/>
        </module>
        <module name="IllegalImport"/>
        <module name="RedundantImport"/>
        <module name="UnusedImports"/>
        <module name="OneTopLevelClass"/>
        <module name="OverloadMethodsDeclarationOrder">
            <property name="severity" value="ignore"/>
        </module>


        <!-- 3. Formatting -->
        <module name="LineLength">
            <property name="severity" value="ignore"/>
            <property name="max" value="200"/>
            <property name="ignorePattern"
                      value="^package.*|^import.*|a href|href|http://|https://|ftp://|^\{.*\}"/>
        </module>
        <module name="MethodLength">
            <property name="max" value="300"/>
        </module>
        <module name="ParameterNumber">
            <property name="severity" value="ignore"/>
        </module>
        <module name="NoLineWrap"/>
        <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="NeedBraces">
            <property name="allowSingleLineStatement" value="true"/>
        </module>
        <module name="LeftCurly"/>
        <module name="RightCurly">
            <property name="id" value="RightCurlySame"/>
            <property name="tokens"
                      value="LITERAL_TRY, LITERAL_CATCH, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_DO"/>
        </module>
        <module name="RightCurly">
            <property name="id" value="RightCurlyAlone"/>
            <property name="option" value="alone"/>
            <property name="tokens"
                      value="CLASS_DEF, METHOD_DEF, CTOR_DEF, LITERAL_FOR, LITERAL_WHILE, STATIC_INIT, INSTANCE_INIT"/>
        </module>
        <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 not part of a multi-block statement (4.1.3)"/>
            <message key="ws.notPreceded"
                     value="WhitespaceAround: ''{0}'' is not preceded with whitespace."/>
        </module>
        <module name="OneStatementPerLine">
            <property name="severity" value="info"/>
        </module>
        <module name="MultipleVariableDeclarations">
            <property name="severity" value="ignore"/>
        </module>
        <module name="ArrayTypeStyle"/>
        <module name="ModifierOrder">
            <property name="severity" value="ignore"/>
        </module>
        <module name="RedundantModifier">
            <property name="severity" value="ignore"/>
        </module>
        <module name="EmptyLineSeparator">
            <property name="severity" value="ignore"/>
            <property name="allowNoEmptyLineBetweenFields" value="true"/>
        </module>
        <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">
            <!-- ELLIPSIS is EOL until https://github.com/google/styleguide/issues/258 -->
            <property name="id" value="SeparatorWrapEllipsis"/>
            <property name="tokens" value="ELLIPSIS"/>
            <property name="option" value="EOL"/>
        </module>
        <module name="SeparatorWrap">
            <!-- ARRAY_DECLARATOR is EOL until https://github.com/google/styleguide/issues/259 -->
            <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">
            <message key="ws.followed"
                     value="GenericWhitespace ''{0}'' is followed by whitespace."/>
            <message key="ws.preceded"
                     value="GenericWhitespace ''{0}'' is preceded with whitespace."/>
            <message key="ws.illegalFollow"
                     value="GenericWhitespace ''{0}'' should followed by whitespace."/>
            <message key="ws.notPreceded"
                     value="GenericWhitespace ''{0}'' is not preceded with whitespace."/>
        </module>
        <module name="Indentation">
            <property name="severity" value="ignore"/>
            <property name="basicOffset" value="4"/>
            <property name="lineWrappingIndentation" value="8"/>
        </module>
        <module name="AbbreviationAsWordInName">
            <property name="severity" value="ignore"/>
        </module>
        <module name="VariableDeclarationUsageDistance">
            <property name="severity" value="ignore"/>
            <property name="allowedDistance" value="4"/>
        </module>
        <module name="EmptyForIteratorPad"/>
        <module name="MethodParamPad"/>
        <module name="NoWhitespaceBefore">
            <property name="tokens"
                      value="COMMA, SEMI, POST_INC, POST_DEC, DOT, ELLIPSIS, METHOD_REF"/>
            <property name="allowLineBreaks" value="true"/>
        </module>
        <module name="NoWhitespaceAfter"/>
        <module name="ParenPad"/>
        <module name="OperatorWrap">
            <property name="option" value="NL"/>
            <property name="tokens"
                      value="BAND, BOR, BSR, BXOR, DIV, EQUAL, GE, GT, LAND, LE, LITERAL_INSTANCEOF, LOR, LT, MINUS, MOD, NOT_EQUAL, QUESTION, SL, SR, STAR, METHOD_REF "/>
        </module>
        <module name="CommentsIndentation">
            <property name="severity" value="info"/>
        </module>
        <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>


        <!-- 4. Naming -->
        <module name="MethodName">
            <property name="severity" value="ignore"/>
            <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9_]*$"/>
            <message key="name.invalidPattern"
                     value="Method name ''{0}'' must match pattern ''{1}''."/>
        </module>
        <module name="PackageName">
            <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$"/>
            <message key="name.invalidPattern"
                     value="Package name ''{0}'' must match pattern ''{1}''."/>
        </module>
        <module name="TypeName">
            <property name="format" value="^[A-Z][a-zA-Z0-9_]*$"/>
            <message key="name.invalidPattern"
                     value="Type name ''{0}'' must match pattern ''{1}''."/>
        </module>
        <module name="MemberName">
            <property name="severity" value="ignore"/>
            <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9]*$"/>
            <property name="applyToPublic" value="true"/>
            <property name="applyToPackage" value="false"/>
            <property name="applyToPrivate" value="false"/>
            <property name="applyToProtected" value="false"/>
            <message key="name.invalidPattern"
                     value="Member name ''{0}'' must match pattern ''{1}''."/>
        </module>
        <module name="MemberName">
            <property name="severity" value="ignore"/>
            <property name="format" value="^m[A-Z][a-zA-Z0-9]*$"/>
            <property name="applyToPublic" value="false"/>
            <property name="applyToProtected" value="true"/>
            <property name="applyToPackage" value="true"/>
            <property name="applyToPrivate" value="true"/>
            <message key="name.invalidPattern"
                     value="Member name ''{0}'' must match pattern ''{1}''."/>
        </module>
        <module name="ParameterName">
            <property name="severity" value="ignore"/>
            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
            <message key="name.invalidPattern"
                     value="Parameter name ''{0}'' must match pattern ''{1}''."/>
        </module>
        <module name="LambdaParameterName">
            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
            <message key="name.invalidPattern"
                     value="Lambda parameter name ''{0}'' must match pattern ''{1}''."/>
        </module>
        <module name="CatchParameterName">
            <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
            <message key="name.invalidPattern"
                     value="Catch parameter name ''{0}'' must match pattern ''{1}''."/>
        </module>
        <module name="LocalVariableName">
            <property name="severity" value="info"/>
            <property name="tokens" value="VARIABLE_DEF"/>
            <property name="format" value="^[a-z]([a-zA-Z0-9][a-zA-Z0-9]*)?$"/>
            <message key="name.invalidPattern"
                     value="Local variable name ''{0}'' must match pattern ''{1}''."/>
        </module>
        <module name="ClassTypeParameterName">
            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
            <message key="name.invalidPattern"
                     value="Class type name ''{0}'' must match pattern ''{1}''."/>
        </module>
        <module name="MethodTypeParameterName">
            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
            <message key="name.invalidPattern"
                     value="Method type name ''{0}'' must match pattern ''{1}''."/>
        </module>
        <module name="InterfaceTypeParameterName">
            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
            <message key="name.invalidPattern"
                     value="Interface type name ''{0}'' must match pattern ''{1}''."/>
        </module>
        <module name="ConstantName"/>
        <module name="LocalFinalVariableName"/>
        <module name="StaticVariableName"/>


        <!-- 5. Programming Practise -->
        <module name="NoFinalizer"/>
        <module name="EmptyCatchBlock">
            <property name="exceptionVariableName" value="expected|ignored"/>
        </module>
        <module name="MissingSwitchDefault"/>
        <module name="FallThrough"/>
        <module name="UpperEll">
        </module>
        <!-- Checks for common coding problems               -->
        <!-- See http://checkstyle.sf.net/config_coding.html -->
        <!--<module name="AvoidInlineConditionals"/>-->
        <module name="CovariantEquals"/>
        <module name="EmptyStatement"/>
        <!--<module name="EqualsAvoidNull"/>-->
        <module name="EqualsHashCode"/>
        <!--<module name="HiddenField"/>-->
        <module name="IllegalInstantiation"/>
        <!--<module name="InnerAssignment"/>-->
        <!--<module name="MagicNumber"/>-->
        <module name="SimplifyBooleanExpression"/>
        <module name="SimplifyBooleanReturn"/>
        <!-- Checks for class design                         -->
        <!-- See http://checkstyle.sf.net/config_design.html -->
        <!--<module name="DesignForExtension"/>-->
        <!--<module name="FinalClass"/>-->
        <!--<module name="HideUtilityClassConstructor"/>-->
        <!--<module name="InterfaceIsType"/>-->
        <!--<module name="VisibilityModifier"/>-->
        <!-- Others -->
        <module name="StringLiteralEquality"/>
        <module name="NestedForDepth">
            <property name="max" value="2"/>
        </module>
        <module name="NestedIfDepth">
            <property name="max" value="3"/>
        </module>
        <module name="ReturnCount">
            <property name="severity" value="ignore"/>
            <property name="max" value="3"/>
        </module>
        <module name="NestedTryDepth ">
            <property name="max" value="3"/>
        </module>
        <module name="SuperClone"/>
        <module name="SuperFinalize"/>
        <module name="UncommentedMain">
            <property name="excludedClasses" value=".*[Application,Test]$"/>
        </module>

        <!-- 6. Javadoc -->
        <module name="NonEmptyAtclauseDescription">
            <property name="severity" value="ignore"/>
        </module>
        <module name="JavadocTagContinuationIndentation">
            <property name="severity" value="ignore"/>
        </module>
        <module name="SummaryJavadoc">
            <property name="severity" value="ignore"/>
            <property name="forbiddenSummaryFragments"
                      value="^@return the *|^This method returns |^A [{]@code [a-zA-Z0-9]+[}]( is a )"/>
        </module>
        <module name="JavadocParagraph">
            <property name="severity" value="ignore"/>
        </module>
        <module name="AtclauseOrder">
            <property name="severity" value="ignore"/>
            <property name="tagOrder" value="@param, @return, @throws, @deprecated"/>
            <property name="target"
                      value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF, VARIABLE_DEF"/>
        </module>
        <module name="JavadocMethod">
            <property name="severity" value="ignore"/>
            <property name="scope" value="public"/>
            <property name="allowMissingParamTags" value="true"/>
            <property name="allowMissingThrowsTags" value="true"/>
            <property name="allowMissingReturnTag" value="true"/>
            <property name="minLineCount" value="2"/>
            <property name="allowedAnnotations" value="Override, Test"/>
            <property name="allowThrowsTagsForSubclasses" value="true"/>
        </module>
        <module name="SingleLineJavadoc">
            <property name="severity" value="ignore"/>
            <property name="ignoreInlineTags" value="false"/>
        </module>


        <!-- *. Others -->
        <module name="RegexpSinglelineJava">
            <property name="severity" value="ignore"/>
            <!-- . matches any character, so we need to
                 escape it and use \. to match dots. -->
            <property name="format" value="System\.(out)|(err)\.print(ln)?\("/>
            <property name="ignoreComments" value="true"/>
        </module>
        <module name="Regexp">
            <property name="format" value="System\.out\.println"/>
            <property name="illegalPattern" value="true"/>
        </module>
    </module>
</module>