checkstyle.xml

<?xml version="1.0"?>
<!DOCTYPE module PUBLIC
    "-//Puppy Crawl//DTD Check Configuration 1.2//EN"
    "http://www.puppycrawl.com/dtds/configuration_1_2.dtd">
<module name="Checker">
  <module name="NewlineAtEndOfFile"/>

  <module name="FileLength"/>

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

  <module name="RegexpSingleline">
    <property name="format" value="\s+$"/>
    <property name="message" value="Line has trailing spaces."/>
  </module>

  <!-- use eclipse-style supression comments -->
  <module name="SuppressionCommentFilter">
    <property name="offCommentFormat" value="@formatter:off"/>
    <property name="onCommentFormat" value="@formatter:on"/>
  </module>

  <module name="SuppressionFilter">
    <property name="file" value="${basedir}/suppressions.xml"/>
  </module>

  <module name="TreeWalker">
    <property name="cacheFile" value="${basedir}/.cache/checkstyle-cache"/>

    <module name="LineLength">
      <property name="max" value="100"/>
    </module>

    <module name="FileContentsHolder"/>
    <module name="LocalFinalVariableName"/>
    <module name="LocalVariableName"/>
    <module name="MemberName"/>
    <module name="MethodName"/>
    <module name="PackageName"/>
    <module name="ParameterName"/>
    <module name="StaticVariableName"/>
    <module name="TypeName"/>
    <module name="AvoidStarImport"/>
    <module name="IllegalImport"/>
    <module name="RedundantImport"/>
    <module name="UnusedImports"/>
    <module name="MethodLength"/>
    <module name="EmptyForIteratorPad"/>
    <module name="MethodParamPad"/>
    <module name="NoWhitespaceAfter"/>
    <module name="NoWhitespaceBefore"/>
    <module name="ParenPad"/>
    <module name="TypecastParenPad"/>
    <module name="WhitespaceAfter"/>
    <module name="WhitespaceAround"/>
    <module name="ModifierOrder"/>
    <module name="LeftCurly"/>
    <module name="NeedBraces"/>
    <module name="RightCurly"/>
    <module name="EmptyStatement"/>
    <module name="EqualsHashCode"/>
    <module name="IllegalInstantiation"/>
    <module name="MissingSwitchDefault"/>
    <module name="SimplifyBooleanExpression"/>
    <module name="ArrayTypeStyle"/>
    <module name="UpperEll"/>
  </module>

  <module name="Header">
    <property name="headerFile" value="${basedir}/tools/java.header"/>
    <property name="ignoreLines" value="2"/>
    <property name="fileExtensions" value="java"/>
  </module>
</module>