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="charset" value="UTF-8"/>
    <module name="TreeWalker">
        <module name="ExtendedMissingJavadocMethod">
            <!-- ignore constructors -->
            <property name="tokens" value="INTERFACE_DEF,CLASS_DEF,ENUM_DEF,METHOD_DEF,ANNOTATION_FIELD_DEF"/>
            <property name="scope" value="protected"/>
            <property name="allowMissingPropertyJavadoc" value="true"/>
        </module>
        <module name="JavadocMethod">
            <property name="accessModifiers" value="public,protected"/>
            <property name="allowMissingParamTags" value="false"/>
        </module>
        <module name="ExtendedMissingJavadocType">
            <property name="scope" value="protected"/>
        </module>
        <module name="JavadocStyle"/>
        <module name="JavadocParagraph"/>
        <module name="JavadocContentLocationCheck"/>
        <module name="RequireEmptyLineBeforeBlockTagGroup"/>
    </module>
</module>