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="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="SuppressionFilter">
        <property name="file" value="${org.checkstyle.sun.suppressionfilter.config}"
                  default="checkstyle-suppressions.xml"/>
        <property name="optional" value="true"/>
    </module>

    <module name="NewlineAtEndOfFile"/>

    <module name="LineLength">
        <property name="max" value="120"/>
        <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://"/>
    </module>

    <module name="FileTabCharacter"/>

    <module name="RegexpMultiline">
        <property name="id" value="blankStartLineControlFlowStatement"/>
        <property name="message"
                  value="Blank line at start of control flow statement(condition, looping, exception) should be removed"/>
        <property name="format" value="(?:\s|^)(?:if|else|while|for|do|try|catch|finally)\s.*\{\s*\n\s*\n"/>
        <property name="fileExtensions" value="java"/>
    </module>

    <module name="RegexpMultiline">
        <property name="id" value="blankStartLineMethods"/>
        <property name="message" value="Blank line at start of method should be removed"/>
        <property name="format" value="(?:\s|^)(private|protected|public)(?!.*\brecord\b).*\(.*\).*\{\s*\n\s*\n"/>
        <property name="fileExtensions" value="java"/>
    </module>

    <module name="RegexpMultiline">
        <property name="id" value="blankEndLine"/>
        <property name="message" value="Blank line at end of block should be removed"/>
        <property name="format" value="(?&lt;!\{\s{0,99}$)^$(?=^\s{0,99}\})"/>
        <property name="fileExtensions" value="groovy,java"/>
    </module>

    <module name="SuppressWarningsFilter"/>

    <module name="TreeWalker">

        <!-- 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"/>
        <module name="LambdaParameterName"/>
        <module name="CatchParameterName"/>

        <!-- Checks for whitespace -->
        <module name="EmptyForIteratorPad"/>
        <module name="GenericWhitespace"/>
        <module name="MethodParamPad"/>
        <module name="NoWhitespaceAfter"/>
        <module name="NoWhitespaceBefore"/>
        <module name="ParenPad"/>
        <module name="TypecastParenPad"/>
        <module name="WhitespaceAfter"/>
        <module name="WhitespaceAround">
            <property name="allowEmptyTypes" value="true"/>
        </module>

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

        <!-- Checks for blocks -->
        <module name="AvoidNestedBlocks"/>
        <module name="EmptyBlock"/>
        <module name="LeftCurly"/>
        <module name="NeedBraces"/>
        <module name="RightCurly"/>

        <!-- Checks for common coding problems -->
        <module name="MultipleVariableDeclarations"/>

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

        <!-- Checks for unused and redundant imports -->
        <module name="UnusedImports"/>
        <module name="RedundantImport"/>

        <!-- Other -->
        <module name="EmptyLineSeparator">
            <property name="allowNoEmptyLineBetweenFields" value="true"/>
            <property name="allowMultipleEmptyLines" value="false"/>
            <property name="allowMultipleEmptyLinesInsideClassMembers" value="false"/>
        </module>

        <module name="UnnecessaryParentheses"/>
        <module name="OneTopLevelClass"/>
        <module name="NoArrayTrailingComma"/>
        <module name="NoEnumTrailingComma"/>
        <module name="UnnecessarySemicolonAfterTypeMemberDeclaration"/>
        <module name="UnnecessarySemicolonInEnumeration"/>
        <module name="UnnecessarySemicolonInTryWithResources"/>

        <module name="SuppressWarningsHolder"/>

        <module name="AvoidDoubleBraceInitialization"/>
        <module name="AvoidNoArgumentSuperConstructorCall"/>
        <module name="NoEnumTrailingComma"/>
        <module name="UnnecessarySemicolonAfterOuterTypeDeclaration"/>
        <module name="NoCodeInFile"/>
        <module name="NoWhitespaceBeforeCaseDefaultColon"/>
        <module name="UnusedLocalVariable"/>

        <module name="SimplifyBooleanReturn"/>
        <module name="SimplifyBooleanExpression"/>
        <module name="EqualsAvoidNull"/>

        <module name="NestedForDepth">
            <property name="max" value="2"/>
        </module>
        <module name="NestedIfDepth">
            <property name="max" value="2"/>
        </module>
        <module name="NestedTryDepth">
            <property name="max" value="2"/>
        </module>

        <!-- JDK 21-->
        <!--        <module name="ConstructorsDeclarationGrouping"/>-->
        <!--        <module name="MissingNullCaseInSwitch"/>-->
        <!--        <module name="WhenShouldBeUsed"/>-->
        <!--        <module name="SealedShouldHavePermitsList"/>-->
    </module>

</module>