checkstyle.xml

<?xml version="1.0"?>
<!DOCTYPE module PUBLIC
    "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
    "https://checkstyle.org/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"/>

    <!-- Excludes all 'module-info.java' files -->
    <module name="BeforeExecutionExclusionFileFilter">
        <property name="fileNamePattern" value="module\-info\.java$"/>
    </module>

    <!-- Whitespace -->
    <module name="FileTabCharacter">
        <property name="eachLine" value="true"/>
    </module>

    <module name="TreeWalker">
        <!-- Naming Conventions -->
        <module name="TypeName"/>
        <module name="MethodName"/>
        <module name="PackageName"/>
        <module name="ConstantName"/>
        <module name="LocalFinalVariableName"/>
        <module name="LocalVariableName"/>
        <module name="MemberName"/>
        <module name="ParameterName"/>
        <module name="StaticVariableName"/>

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

        <!-- Size Violations -->
        <module name="MethodLength">
            <property name="tokens" value="METHOD_DEF"/>
            <property name="max" value="150"/>
        </module>
        <module name="ParameterNumber">
            <property name="max" value="7"/>
        </module>
        <module name="LineLength">
            <property name="max" value="120"/>
            <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
        </module>

        <!-- Whitespace -->
        <module name="EmptyForIteratorPad"/>
        <module name="GenericWhitespace"/>
        <module name="MethodParamPad"/>
        <module name="NoWhitespaceAfter"/>
        <module name="NoWhitespaceBefore"/>
        <module name="OperatorWrap"/>
        <module name="ParenPad"/>
        <module name="TypecastParenPad"/>
        <module name="WhitespaceAfter"/>
        <module name="WhitespaceAround"/>

        <!-- Modifier Checks -->
        <module name="ModifierOrder"/>
        <module name="RedundantModifier"/>

        <!-- Blocks -->
        <module name="AvoidNestedBlocks"/>
        <module name="EmptyBlock"/>
        <module name="LeftCurly"/>
        <module name="NeedBraces"/>
        <module name="RightCurly"/>

        <!-- Common Coding Problems -->
        <module name="EmptyStatement"/>
        <module name="EqualsHashCode"/>
        <module name="HiddenField">
            <property name="ignoreConstructorParameter" value="true"/>
            <property name="ignoreSetter" value="true"/>
        </module>
        <module name="IllegalInstantiation"/>
        <module name="InnerAssignment"/>
        <module name="MagicNumber">
            <property name="ignoreNumbers" value="-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 100, 1000"/>
        </module>
        <module name="MissingSwitchDefault"/>
        <module name="SimplifyBooleanExpression"/>
        <module name="SimplifyBooleanReturn"/>

        <!-- Class Design -->
        <module name="DesignForExtension"/>
        <module name="FinalClass"/>
        <module name="HideUtilityClassConstructor"/>
        <module name="InterfaceIsType"/>
        <module name="VisibilityModifier"/>

        <!-- Miscellaneous -->
        <module name="ArrayTypeStyle"/>
        <module name="FinalParameters"/>
        <module name="TodoComment"/>
        <module name="UpperEll"/>
    </module>
</module>