codestyle.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">
    <!-- Checks for whitespace -->
    <module name="FileTabCharacter"/>

    <!-- Checks for line length -->
    <module name="LineLength">
        <property name="max" value="120"/>
        <property name="ignorePattern" value="^ *\*.+$"/>
    </module>

    <!-- TreeWalker children require Java Parser -->
    <module name="TreeWalker">
        <!-- Checks for Javadoc comments -->
        <module name="JavadocMethod">
            <property name="accessModifiers" value="public"/>
        </module>
        <module name="MissingJavadocMethodCheck">
            <property name="allowMissingPropertyJavadoc" value="true"/>
        </module>
        <module name="JavadocType">
            <property name="scope" value="public"/>
        </module>
        <module name="JavadocStyle">
            <property name="scope" value="public"/>
            <property name="checkFirstSentence" value="false"/>
        </module>

        <!-- Checks for Naming Conventions -->
        <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 -->
        <module name="AvoidStarImport"/>
        <module name="IllegalImport"/> <!-- defaults to sun.* packages -->
        <module name="RedundantImport"/>
        <module name="UnusedImports"/>

        <!-- Checks for Size Violations -->
        <module name="MethodLength">
            <property name="max" value="50"/>
            <property name="countEmpty" value="false"/>
        </module>
        <module name="ParameterNumber"/>

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

        <!-- Checks for blocks. You know, those {}'s  -->
        <module name="AvoidNestedBlocks"/>
        <module name="LeftCurly">
            <property name="option" value="eol"/>
        </module>
        <module name="NeedBraces">
            <property name="allowSingleLineStatement" value="false"/>
        </module>
        <module name="RightCurly"/>

        <!-- Checks for common coding problems -->
        <module name="EmptyStatement"/>
        <module name="EqualsHashCode"/>
        <module name="MissingSwitchDefault"/>
        <module name="SimplifyBooleanExpression"/>
        <module name="SimplifyBooleanReturn"/>

        <!-- Checks for class design -->
        <module name="FinalClass"/>
        <module name="InterfaceIsType"/>
        <module name="VisibilityModifier">
            <property name="protectedAllowed" value="true"/>
        </module>

        <!-- Miscellaneous other checks -->
        <module name="ArrayTypeStyle"/>

        <!-- Number of method parameters -->
        <module name="ParameterNumber">
            <property name="max" value="12"/>
        </module>
    </module>
</module>