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">
    <module name="RegexpMultiline">
        <property name="format" value="(?s:(\r\n|\r).*)" />
        <property name="message"
            value="CRLF and CR line endings are prohibited, but this file uses them." />
    </module>
    <module name="TreeWalker">
        <module name="CustomImportOrder">
            <property name="customImportOrderRules"
                value="STATIC###STANDARD_JAVA_PACKAGE###SPECIAL_IMPORTS###THIRD_PARTY_PACKAGE" />
            <property name="specialImportsRegExp"
                value="^org\." />
            <property name="thirdPartyPackageRegExp"
                value="^com\." />
            <property name="sortImportsInGroupAlphabetically"
                value="true" />
            <property name="separateLineBetweenGroups"
                value="true" />
        </module>
        <module name="UnusedImports"/>
    </module>
</module>