checkstyle-configuration.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="severity" value="error"/>
    <property name="fileExtensions" value="java"/>
    <!-- Excludes all 'module-info.java' files -->
    <module name="BeforeExecutionExclusionFileFilter">
        <property name="fileNamePattern" value="module\-info\.java$"/>
    </module>
    <module name="FileTabCharacter"/>
    <module name="RegexpSingleline">
        <property name="format" value="\s+$"/>
        <property name="minimum" value="0"/>
        <property name="maximum" value="0"/>
        <property name="message" value="Line has trailing spaces."/>
    </module>
    <module name="TreeWalker">
        <module name="InvalidJavadocPosition"/>
        <module name="RedundantImport"/>
        <module name="UnusedImports">
            <property name="processJavadoc" value="true"/>
        </module>
        <module name="GenericWhitespace"/>
        <module name="MethodParamPad"/>
        <module name="ParenPad"/>
        <module name="TypecastParenPad"/>
        <module name="NoWhitespaceAfter"/>
        <module name="NoWhitespaceBefore"/>
        <module name="WhitespaceAround">
            <property name="tokens"
                      value="ASSIGN,DIV_ASSIGN,PLUS_ASSIGN,MINUS_ASSIGN,STAR_ASSIGN,
                      MOD_ASSIGN,SR_ASSIGN,BSR_ASSIGN,SL_ASSIGN,BXOR_ASSIGN,
                      BOR_ASSIGN,BAND_ASSIGN, LCURLY,RCURLY"/>
        </module>
        <module name="ModifierOrder"/>
        <module name="AvoidNestedBlocks"/>
        <module name="LeftCurly"/>
        <module name="NeedBraces"/>
        <module name="RightCurly"/>
        <module name="EmptyStatement"/>
        <module name="EqualsHashCode"/>
        <!-- Checks that a local variable does not shadow a field defined in the same class. -->
        <module name="HiddenField">
            <property name="tokens" value="VARIABLE_DEF"/>
        </module>
        <module name="IllegalInstantiation"/>
        <module name="SimplifyBooleanExpression"/>
        <module name="SimplifyBooleanReturn"/>
        <module name="InterfaceIsType"/>
        <!-- Checks comments are indented at the same level as surrounding code -->
        <module name="CommentsIndentation"/>
        <!-- Checks that array type definitions use Java style (e.g., char[] arr vs char arr[] -->
        <module name="ArrayTypeStyle"/>
        <!-- Checks that long constants are defined with an upper ell -->
        <module name="UpperEll"/>
    </module>
</module>