src/main/checkstyle/checks.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE module PUBLIC
    "-//Puppy Crawl//DTD Check Configuration 1.2//EN"
    "http://www.puppycrawl.com/dtds/configuration_1_2.dtd">

<module name="Checker">

  <!-- limit source file size -->
  <module name="FileLength">
    <property name="max" value="2000"/>
  </module>

  <!-- require a header -->
  <module name="RegexpHeader">
    <property name="headerFile" value="${checkstyle.header.file}"/>
    <property name="fileExtensions" value="java"/>
  </module>

  <!-- forbid tab characters in source files -->
  <module name="FileTabCharacter"/>

  <module name="SuppressionCommentFilter">
    <property name="offCommentFormat" value="CheckStyle\:([\w\|]+) OFF"/>
    <property name="onCommentFormat" value="CheckStyle\:([\w\|]+) ON"/>
    <property name="checkFormat" value="$1"/>
  </module>
  <module name="NewlineAtEndOfFile">
    <property name="fileExtensions" value="java"/>
  </module>
  <module name="TreeWalker">
    <property name="tabWidth" value="2"/>

    <module name="FileContentsHolder"/>

    <!--  annotations -->
    <module name="AnnotationUseStyle"/>
    <module name="MissingDeprecated"/>
    <module name="MissingOverride"/>
    <module name="SuppressWarnings"/>

    <!-- javadocs -->
    <module name="JavadocType">
      <property name="authorFormat" value="\S+"/>
    </module>
    <module name="JavadocMethod">
      <property name="allowThrowsTagsForSubclasses" value="true"/>
      <property name="allowUndeclaredRTE" value="true"/>
    </module>
    <module name="JavadocVariable"/>
    <module name="JavadocStyle">
      <property name="checkFirstSentence" value="false"/>
    </module>

    <!-- naming -->
    <module name="AbstractClassName">
      <property name="format" value="^Abstract.*$"/>
    </module>
    <module name="ClassTypeParameterName"/>
    <module name="ConstantName"/>
    <module name="LocalFinalVariableName"/>
    <module name="LocalVariableName"/>
    <module name="MemberName"/>
    <module name="MethodName"/>
    <module name="MethodTypeParameterName"/>
    <module name="PackageName"/>
    <module name="ParameterName"/>
    <module name="StaticVariableName"/>
    <module name="TypeName"/>

    <!-- imports -->
    <module name="AvoidStarImport"/>
    <module name="AvoidStaticImport"/>
    <module name="IllegalImport"/>
    <module name="RedundantImport"/>
    <module name="UnusedImports"/>
    <module name="ImportOrder">
      <property name="groups" value="java,javax"/>
      <property name="ordered" value="true"/>
      <property name="option" value="bottom"/>
    </module>

    <!-- sizes -->
    <module name="LineLength">
      <property name="ignorePattern" value="(^.*\$.*\$.*$)|(^import .*)"/>
      <property name="max" value="120"/>
    </module>
    <module name="MethodLength">
      <property name="max" value="300"/>
    </module>
    <module name="AnonInnerLength">
      <property name="max" value="30"/>
    </module>
    <module name="ParameterNumber"/>
    <module name="OuterTypeNumber"/>

    <!-- whitespace -->
    <module name="GenericWhitespace"/>
    <module name="EmptyForInitializerPad"/>
    <module name="EmptyForIteratorPad"/>
    <module name="MethodParamPad"/>
    <module name="NoWhitespaceAfter"/>
    <module name="NoWhitespaceBefore">
      <property name="allowLineBreaks" value="true"/>
      <property name="tokens"
                value="SEMI,DOT,POST_DEC,POST_INC"/>
    </module>
    <module name="OperatorWrap">
      <property name="option" value="eol"/>
      <property name="tokens"
                value="BAND,BOR,BSR,BXOR,DIV,EQUAL,GE,GT,LAND,LE,
                       LITERAL_INSTANCEOF,LOR,LT,MINUS,MOD,NOT_EQUAL,PLUS,
                       SL,SR,STAR"/>
    </module>
    <module name="ParenPad"/>
    <module name="TypecastParenPad"/>
    <module name="WhitespaceAfter"/>
    <module name="WhitespaceAround">
      <property name="tokens"
                value="ASSIGN,BAND,BAND_ASSIGN,BOR,BOR_ASSIGN,BSR,BSR_ASSIGN,
                       BXOR,BXOR_ASSIGN,COLON,DIV,DIV_ASSIGN,EQUAL,GE,GT,LAND,
                       LE,LITERAL_ASSERT,LITERAL_CATCH,LITERAL_DO,
                       LITERAL_ELSE,LITERAL_FINALLY,LITERAL_FOR,LITERAL_IF,
                       LITERAL_RETURN,LITERAL_SYNCHRONIZED,LITERAL_TRY,
                       LITERAL_WHILE,LOR,LT,MINUS,MINUS_ASSIGN,MOD,MOD_ASSIGN,
                       NOT_EQUAL,PLUS_ASSIGN,QUESTION,SL,
                       SL_ASSIGN,SR,SR_ASSIGN,STAR,STAR_ASSIGN"/>
    </module>

    <!-- modifiers -->
    <module name="ModifierOrder"/>
    <module name="RedundantModifier"/>

    <!-- blocks -->
    <module name="EmptyBlock"/>
    <module name="LeftCurly">
      <property name="option" value="nl"/>
      <property name="tokens"
                value="CLASS_DEF,CTOR_DEF,INTERFACE_DEF,METHOD_DEF"/>
    </module>
    <module name="NeedBraces"/>
    <module name="RightCurly"/>
    <module name="AvoidNestedBlocks"/>

    <!-- coding -->
    <module name="ArrayTrailingComma"/>
    <module name="CovariantEquals"/>
    <module name="EmptyStatement"/>
    <module name="EqualsAvoidNull"/>
    <module name="EqualsHashCode"/>
    <module name="FinalLocalVariable"/>
    <module name="HiddenField"/>
    <module name="IllegalInstantiation">
      <property name="classes" value="java.lang.Boolean"/>
    </module>
    <module name="InnerAssignment"/>
    <module name="MagicNumber"/>
    <module name="MissingSwitchDefault"/>
    <module name="SimplifyBooleanExpression"/>
    <module name="SimplifyBooleanReturn"/>
    <module name="StringLiteralEquality"/>
    <module name="NestedIfDepth">
      <property name="max" value="5"/>
    </module>
    <module name="NestedTryDepth">
      <property name="max" value="5"/>
    </module>
    <module name="SuperClone"/>
    <module name="SuperFinalize"/>
    <module name="PackageDeclaration"/>
    <module name="ReturnCount"/>
    <module name="IllegalType">
      <property name="illegalClassNames"
                value="java.util.GregorianCalendar, java.util.Hashtable,
                       java.util.HashSet, java.util.HashMap,
                       java.util.ArrayList, java.util.LinkedList,
                       java.util.LinkedHashMap, java.util.LinkedHashSet,
                       java.util.TreeSet, java.util.TreeMap, java.util.Vector"/>
    </module>
    <module name="DeclarationOrder"/>
    <module name="ParameterAssignment"/>
    <module name="ExplicitInitialization"/>
    <module name="DefaultComesLast"/>
    <module name="FallThrough"/>
    <module name="MultipleVariableDeclarations"/>
    <module name="RequireThis">
      <property name="checkFields" value="false"/>
      <property name="checkMethods" value="false"/>
    </module>
    <module name="UnnecessaryParentheses"/>

    <!-- design -->
    <module name="VisibilityModifier">
      <property name="protectedAllowed" value="true"/>
    </module>
    <module name="FinalClass"/>
    <module name="InterfaceIsType"/>
    <module name="HideUtilityClassConstructor"/>
    <module name="MutableException"/>
    <module name="ThrowsCount">
      <property name="max" value="2"/>
    </module>

    <!-- prevent trailing whitespace -->
    <module name="Regexp">
      <property name="format" value="[ \t]+$"/>
      <property name="illegalPattern" value="true"/>
      <property name="message" value="Trailing whitespace"/>
    </module>

    <!-- misc -->
    <module name="UpperEll"/>
    <module name="ArrayTypeStyle"/>
    <module name="FinalParameters"/>
    <module name="Indentation">
      <property name="basicOffset" value="2"/>
      <property name="caseIndent" value="0"/>
      <property name="throwsIndent" value="2"/>
      <property name="arrayInitIndent" value="2"/>
      <property name="lineWrappingIndentation" value="2"/>
    </module>
    <module name="TrailingComment"/>

  </module>
</module>