make/conf/checkstyle-langtools.xml

<?xml version="1.0"?>
<!DOCTYPE module PUBLIC
          "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
          "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">

<!--
   Checks for initial langtools code conventions, we are starting with
   imports and import orders and this will grow to encompass other
   violations over time. 
-->

<module name="Checker">
    
    <!-- Checks for whitespace. -->
    <module name="FileTabCharacter">
        <property name="fileExtensions" value=".java"/>
    </module>

    <!-- Miscellaneous other checks.                   -->
    <module name="RegexpSingleline">
        <property name="format" value="\s+$"/>
        <property name="minimum" value="0"/>
        <property name="maximum" value="0"/>
        <property name="message" value="Line has trailing spaces."/>
        <property name="fileExtensions" value=".java .html"/>
    </module>

    <module name="TreeWalker">
    <!-- Checks for imports                              -->
    <!--
        <module name="AvoidStarImport"/>
        <module name="IllegalImport"/>
    -->
        <module name="GenericWhitespace"/>
        <module name="RedundantImport"/>
        <module name="UnusedImports"/>  
        <module name="ImportOrder">
            <property name="groups" value="java, javax, org, com"/>
            <property name="ordered" value="true"/>
            <property name="separated" value="true"/>
        </module>        
        <module name="EmptyForInitializerPad">
            <property name="option" value="space"/>
        </module>
        <module name="WhitespaceAfter"/>
    </module>
</module>