checkstyle.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE module PUBLIC
    "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
    "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">

<module name="Checker">
    <property name="charset" value="UTF-8"/>
    <module name="TreeWalker">
        <module name="AnnotationLocation">
            <property name="allowSamelineSingleParameterlessAnnotation" value="false"/>
        </module>
        <module name="AnnotationUseStyle"/>
        <module name="MissingDeprecated"/>
        <module name="MissingOverride"/>
        <module name="AvoidNestedBlocks">
            <property name="allowInSwitchCase" value="true"/>
        </module>
        <module name="LeftCurly">
            <property name="ignoreEnums" value="false"/>
        </module>
        <module name="NeedBraces"/>
        <module name="RightCurly"/>
        <module name="HideUtilityClassConstructor"/>
        <module name="OneTopLevelClass"/>
        <module name="VisibilityModifier"/>
        <module name="CovariantEquals"/>
        <module name="DeclarationOrder"/>
        <module name="DefaultComesLast"/>
        <module name="EmptyStatement"/>
        <module name="EqualsAvoidNull"/>
        <module name="EqualsHashCode"/>
        <module name="ExplicitInitialization"/>
        <module name="FinalLocalVariable"/>
        <module name="IllegalInstantiation">
            <property name="classes" value="java.lang.Boolean"/>
        </module>
        <module name="IllegalTokenText">
            <property name="tokens" value="NUM_INT,NUM_LONG"/>
            <property name="format" value="^0[^lx]"/>
            <property name="ignoreCase" value="true"/>
        </module>
        <module name="IllegalType">
            <property name="illegalClassNames" value="java.util.HashSet, java.util.HashMap, java.util.TreeSet, java.util.TreeMap"/>
        </module>
        <module name="InnerAssignment"/>
        <module name="MissingSwitchDefault"/>
        <module name="MultipleVariableDeclarations"/>
        <module name="NoFinalizer"/>
        <module name="OneStatementPerLine"/>
        <module name="OverloadMethodsDeclarationOrder"/>
        <module name="PackageDeclaration"/>
        <module name="SimplifyBooleanExpression"/>
        <module name="SimplifyBooleanReturn"/>
        <module name="StringLiteralEquality"/>
        <module name="UnnecessaryParentheses"/>
        <module name="AvoidStarImport"/>
        <module name="IllegalImport">
            <property name="illegalPkgs" value="sun, junit.framework"/>
        </module>
        <module name="RedundantImport"/>
        <module name="UnusedImports"/>
        <module name="ArrayTypeStyle"/>
        <module name="CommentsIndentation"/>
        <!-- Comparing this with null (i.e. this == null and this != null): -->
        <module name="DescendantToken">
            <property name="tokens" value="EQUAL,NOT_EQUAL"/>
            <property name="limitedTokens" value="LITERAL_THIS,LITERAL_NULL"/>
            <property name="maximumNumber" value="1"/>
            <property name="maximumDepth" value="1"/>
            <property name="sumTokenCounts" value="true"/>
        </module>
        <!--The initialiser in for performs no setup (where a while statement could be used instead): -->
        <module name="DescendantToken">
            <property name="tokens" value="FOR_INIT"/>
            <property name="limitedTokens" value="EXPR"/>
            <property name="minimumNumber" value="1"/>
        </module>
        <module name="OuterTypeFilename"/>
        <module name="UpperEll"/>
        <module name="ModifierOrder"/>
        <module name="RedundantModifier"/>
        <module name="ClassTypeParameterName"/>
        <module name="ConstantName"/>
        <module name="InterfaceTypeParameterName"/>
        <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]*)*$"/>
        </module>
        <module name="ParameterName"/>
        <module name="StaticVariableName"/>
        <module name="TypeName"/>
        <module name="OuterTypeNumber"/>
        <module name="GenericWhitespace"/>
        <module name="MethodParamPad"/>
        <!--<module name="ParenPad"/> disabled due to the bug in the NetBeans (nb-javac)
        "try with resources formatting adding extra space" https://github.com/apache/netbeans/issues/3720
        Let's make our life easier, just skip this check temporarily -->
        <module name="TypecastParenPad"/>
        <module name="WhitespaceAfter"/>
        <module name="WhitespaceAround">
            <property name="tokens" value="ASSIGN"/>
        </module>
    </module>
    <module name="LineLength">
        <property name="max" value="120"/>
        <property name="ignorePattern" value="^ *\* *[^ ]+$"/>
    </module>
    <module name="NewlineAtEndOfFile">
        <property name="lineSeparator" value="lf"/>
    </module>
    <module name="UniqueProperties"/>
    <!-- the check to find trailing whitespace at the end of a line: -->
    <module name="RegexpSingleline">
        <!-- \s matches whitespace character, $ matches end of line. -->
        <property name="format" value="\s+$"/>
    </module>
    <module name="FileTabCharacter">
        <property name="eachLine" value="true"/>
    </module>
</module>