checkstyle.xml

<?xml version="1.0"?><!DOCTYPE module PUBLIC
    "-//Puppy Crawl//DTD Check Configuration 1.2//EN"
    "https://www.puppycrawl.com/dtds/configuration_1_2.dtd">

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

    <!-- Trailing spaces -->
    <module name="RegexpSingleline">
        <property name="format" value="\s+$" />
        <property name="message" value="Line has trailing spaces." />
    </module>

    <module name="TreeWalker">
        <!--<property name="cacheFile" value="${checkstyle.cache.file}"/>-->

        <!-- Checks for Javadoc comments.                     -->
        <!-- See https://checkstyle.sf.net/config_javadoc.html -->
        <!--module name="JavadocMethod"/-->
        <!--module name="JavadocType"/-->
        <!--module name="JavadocVariable"/-->
        <!--module name="JavadocStyle"/-->

        <!-- Checks for Naming Conventions.                  -->
        <!-- See https://checkstyle.sf.net/config_naming.html -->
        <module name="ConstantName" />
        <module name="LocalFinalVariableName" />
        <module name="LocalVariableName" />
        <module name="MemberName" />
        <module name="MethodName" />
        <module name="PackageName" />
        <module name="ParameterName" />
        <module name="StaticVariableName" />
        <module name="TypeName" />

        <!-- Checks for imports                              -->
        <!-- See https://checkstyle.sf.net/config_import.html -->
        <module name="AvoidStarImport" />
        <module name="IllegalImport" /> <!-- defaults to sun.* packages -->
        <module name="RedundantImport" />
        <module name="UnusedImports">
            <property name="processJavadoc" value="true" />
        </module>

        <!-- Checks for Size Violations.                    -->
        <!-- See https://checkstyle.sf.net/config_sizes.html -->
        <module name="LineLength">
            <property name="max" value="100" />
        </module>
        <!--<module name="MethodLength"/>-->
        <!--module name="ParameterNumber"/-->

        <!-- Checks for whitespace                               -->
        <!-- See https://checkstyle.sf.net/config_whitespace.html -->
        <module name="GenericWhitespace" />
        <module name="EmptyForIteratorPad" />
        <module name="MethodParamPad" />
        <module name="NoWhitespaceAfter">
            <property name="tokens" value="BNOT, DEC, DOT, INC, LNOT, UNARY_MINUS, UNARY_PLUS" />
        </module>
        <module name="NoWhitespaceBefore" />
        <module name="OperatorWrap" />
        <module name="ParenPad" />
        <module name="TypecastParenPad" />
        <module name="WhitespaceAfter" />
        <module name="WhitespaceAround" />

        <!-- Modifier Checks                                    -->
        <!-- See https://checkstyle.sf.net/config_modifiers.html -->
        <module name="ModifierOrder" />
        <module name="RedundantModifier" />

        <!-- Checks for blocks. You know, those {}'s         -->
        <!-- See https://checkstyle.sf.net/config_blocks.html -->
        <!--module name="AvoidNestedBlocks"/-->
        <!--module name="EmptyBlock"/-->
        <module name="LeftCurly" />
        <!--module name="NeedBraces"/-->
        <module name="RightCurly" />

        <!-- Checks for common coding problems               -->
        <!-- See https://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="MissingSwitchDefault" />
        <module name="SimplifyBooleanExpression" />
        <module name="SimplifyBooleanReturn" />

        <!-- Checks for class design                         -->
        <!-- See https://checkstyle.sf.net/config_design.html -->
        <!--module name="DesignForExtension"/-->
        <!--module name="FinalClass"/-->
        <!--module name="HideUtilityClassConstructor"/-->
        <module name="InterfaceIsType" />
        <!--module name="VisibilityModifier"/-->

        <!-- Miscellaneous other checks.                   -->
        <!-- See https://checkstyle.sf.net/config_misc.html -->
        <module name="ArrayTypeStyle" />
        <!--module name="FinalParameters"/-->
        <!--module name="TodoComment"/-->
        <module name="UpperEll" />
    </module>
</module>