checkstyle.xml

<?xml version="1.0"?>
<!DOCTYPE module PUBLIC "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN" "https://checkstyle.org/dtds/configuration_1_3.dtd">

<!-- You have to explicitly indicate to Codacy to load this file
at the project's patterns page on codacy.com.
Otherwise, Codacy will use its default patterns and configuration. -->
<module name="Checker">
    <property name="charset" value="UTF-8" />
    <property name="severity" value="warning"/>

    <module name="JavadocPackage"/>

    <module name="NewlineAtEndOfFile">
        <property name="fileExtensions" value="java, xml, yml"/>
    </module>
    <module name="TreeWalker">
        <module name="OneTopLevelClass"/>
        <module name="OverloadMethodsDeclarationOrder"/>
        <module name="PackageDeclaration"/>
        <module name="PackageName"/>
        <module name="ParameterNumber"/>
        <module name="RedundantImport"/>
        <module name="CyclomaticComplexity"/>
        <module name="RedundantModifier"/>
        <module name="ThrowsCount"/>
        <module name="TodoComment"/>
        <module name="UnusedImports"/>
        <module name="VariableDeclarationUsageDistance"/>
        <module name="VisibilityModifier"/>
        <module name="MissingJavadocPackage"/>
        <module name="OneStatementPerLine"/>
        <module name="DeclarationOrder"/>
        <module name="ModifierOrder"/>
        <module name="MultipleStringLiterals"/>
        <module name="MultipleVariableDeclarations"/>
        <module name="NPathComplexity"/>
        <module name="NestedForDepth"/>
        <module name="NestedTryDepth"/>
        <module name="ExecutableStatementCount">
            <property name="max" value="30"/>
        </module>
        <module name="AnonInnerLength">
            <property name="max" value="20"/>
        </module>
        <module name="BooleanExpressionComplexity">
            <property name="max" value="3"/>
        </module>
        <module name="FinalClass" />
        <module name="HideUtilityClassConstructor" />
        <module name="IllegalThrows" />
        <module name="InnerTypeLast" />
        <module name="MethodCount" />
        <module name="MethodLength" />
        <module name="ModifiedControlVariable" />
    </module>
    <module name="FileLength" />

    <!-- Tone down the checking for test code -->
    <module name="SuppressionSingleFilter">
        <property name="checks" value="JavadocPackage"/>
        <property name="files" value=".*[\\/]src[\\/](test|it)[\\/]" />
    </module>

    <!-- Classes implementing the Null Object Pattern usually have methods with a single instruction
    declared in a single line. -->
    <module name="SuppressionSingleFilter">
        <property name="checks" value="OneStatementPerLine"/>
        <property name="files" value=".*\/.*Null.*\.java" />
    </module>
</module>