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="cacheFile" value="${checkstyle.cache.file}" />
    <property name="severity" value="warning" />
    <property name="fileExtensions" value="java, properties, xml, fxml" />

    <!-- BeforeExecutionFileFilters is required for sources that are based on java9 -->
    <module name="BeforeExecutionExclusionFileFilter">
        <property name="fileNamePattern"
            value="module\-info\.java$" />
    </module>

    <module name="FileTabCharacter">
        <property name="eachLine" value="false" />
    </module>

    <module name="TreeWalker">
        <property name="tabWidth" value="4"/>

        <module name="GenericWhitespace"/>
        <module name="EmptyForInitializerPad"/>
        <module name="EmptyForIteratorPad"/>

        <module name="NoWhitespaceBefore"/>
        <module name="NoWhitespaceBeforeCaseDefaultColon"/>
        <module name="NoWhitespaceBefore">
            <property name="tokens" value="DOT"/>
            <property name="tokens" value="METHOD_REF"/>
            <property name="allowLineBreaks" value="true"/>
        </module>

        <module name="SingleSpaceSeparator">
            <property name="validateComments" value="false"/>
        </module>
        <module name="TypecastParenPad"/>
        
        <module name="EmptyLineSeparator">
            <property name="tokens" value="IMPORT"/>
            <property name="tokens" value="STATIC_IMPORT"/>
            <property name="tokens" value="INTERFACE_DEF"/>
            <property name="tokens" value="INSTANCE_INIT"/>
            <property name="tokens" value="RECORD_DEF"/>
            <property name="allowNoEmptyLineBetweenFields" value="false"/>
            <property name="allowMultipleEmptyLinesInsideClassMembers" value="true"/>
        </module>

        <module name="NoWhitespaceAfter">
            <property name="tokens" value="ARRAY_INIT"/>
            <property name="tokens" value="AT"/>
            <property name="tokens" value="BNOT"/>
            <property name="tokens" value="DEC"/>
            <property name="tokens" value="DOT"/>
            <property name="tokens" value="INC"/>
            <property name="tokens" value="LNOT"/>
            <property name="tokens" value="UNARY_MINUS"/>
            <property name="tokens" value="UNARY_PLUS"/>
            <property name="tokens" value="ARRAY_DECLARATOR"/>
            <property name="tokens" value="INDEX_OP"/>
            <property name="tokens" value="METHOD_REF"/>
        </module>    

        <module name="EmptyBlock">
            <property name="tokens" value="LITERAL_CATCH"/>
            <property name="tokens" value="LITERAL_DEFAULT"/>
            <property name="tokens" value="LITERAL_CASE"/>
            <property name="tokens" value="INSTANCE_INIT"/>
            <property name="tokens" value="STATIC_INIT"/>
            <property name="tokens" value="LITERAL_DO"/>
            <property name="tokens" value="LITERAL_ELSE"/>
            <property name="tokens" value="LITERAL_FINALLY"/>
            <property name="tokens" value="LITERAL_FOR"/>
            <property name="tokens" value="LITERAL_IF"/>
            <property name="tokens" value="LITERAL_SWITCH"/>
            <property name="tokens" value="LITERAL_TRY"/>
            <property name="tokens" value="LITERAL_SYNCHRONIZED"/>
            <property name="tokens" value="LITERAL_WHILE"/>
            <property name="option" value="text"/>
        </module>

        <module name="OperatorWrap"/>
        <module name="WhitespaceAfter"/>
        <module name="WhitespaceAround"/>
    </module>
</module>