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">

<!--
  - Some of the checks are commented out. This is because they require newer version of Checkstyle, which in turn
  - requires Java 7. This project currently builds with Java 6 and uses the latest Checkstyle version that supports it.
  -->
<module name="Checker">
    <property name="charset" value="UTF-8"/>

    <module name="SuppressionFilter">
        <property name="file" value="checkstyle-suppressions.xml"/>
    </module>

    <!-- no tabs -->
    <module name="FileTabCharacter">
        <property name="eachLine" value="true"/>
    </module>

    <!-- no trailing spaces -->
    <module name="RegexpSingleline">
        <property name="format" value="\s+$"/>
        <property name="message" value="Line has trailing spaces."/>
    </module>

    <!-- mandatory newline at end of file -->
    <module name="NewlineAtEndOfFile">
        <property name="lineSeparator" value="lf"/>
    </module>

    <module name="TreeWalker">
        <property name="cacheFile" value="target/cachefile"/>
        <property name="tabWidth" value="4"/>

        <!-- line length -->
        <module name="LineLength">
            <property name="max" value="120"/>
            <property name="ignorePattern" value="^package|^import|href|http://|https://|ftp://|&quot;\p{Punct}*$"/>
        </module>

        <!-- imports -->
        <module name="AvoidStarImport"/>
        <module name="RedundantImport"/>
        <module name="UnusedImports"/>
        <module name="IllegalImport">
            <property name="illegalPkgs" value="sun, junit.framework, org.custommonkey.xmlunit.XMLAssert"/>
        </module>

        <!-- code shape -->
        <module name="DesignForExtension"/>
        <module name="OneTopLevelClass"/>
        <module name="OneStatementPerLine"/>
        <module name="MultipleVariableDeclarations"/>
        <module name="ArrayTypeStyle"/>
        <module name="MissingSwitchDefault"/>
        <module name="DefaultComesLast"/>
        <module name="FallThrough"/>
        <module name="UpperEll"/>
        <module name="RedundantModifier"/>
        <module name="CovariantEquals"/>
        <module name="EqualsHashCode"/>
        <module name="MutableException"/>
        <module name="NoFinalizer"/>
        <module name="ModifierOrder"/>
        <module name="OverloadMethodsDeclarationOrder"/>
        <module name="HideUtilityClassConstructor"/>
        <module name="InnerAssignment"/>
        <module name="PackageAnnotation"/>
        <module name="AnnotationLocation">
            <property name="tokens" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF"/>
            <property name="allowSamelineSingleParameterlessAnnotation" value="false"/>
        </module>
        <module name="AnnotationLocation">
            <property name="tokens" value="VARIABLE_DEF"/>
            <property name="allowSamelineMultipleAnnotations" value="true"/>
        </module>
        <module name="EmptyStatement"/>
        <module name="EmptyBlock">
            <!--
              - This is only needed because current Checkstyle version defaults to including LITERAL_CATCH here.
              - Once the EmptyCatchBlock below is uncommented, which can only happen in a newer Checkstyle version
              - that no longer includes LITERAL_CATCH here by default, this declaration can be removed.
              -->
            <property name="tokens" value="LITERAL_DO, LITERAL_ELSE, LITERAL_FINALLY, LITERAL_IF, LITERAL_FOR, LITERAL_TRY, LITERAL_WHILE, INSTANCE_INIT, STATIC_INIT, LITERAL_SWITCH"/>
        </module>
<!--
        <module name="EmptyCatchBlock">
            <property name="exceptionVariableName" value="expected|ignored"/>
        </module>
-->
<!--
        <module name="NeedBraces">
            <property name="tokens" value="LITERAL_IF"/>
            <property name="allowSingleLineStatement" value="true"/>
        </module>
-->
        <module name="NeedBraces">
            <property name="tokens" value="LITERAL_DO, LITERAL_ELSE, LITERAL_FOR, LITERAL_WHILE"/>
        </module>
        <module name="LeftCurly">
            <property name="maxLineLength" value="120"/>
<!--
            <property name="ignoreEnums" value="false"/>
-->
        </module>
        <module name="RightCurly">
            <property name="option" value="same"/>
            <property name="tokens" value="LITERAL_TRY, LITERAL_CATCH, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE"/>
        </module>
        <module name="RightCurly">
            <property name="option" value="alone"/>
            <property name="tokens" value="CLASS_DEF, METHOD_DEF, CTOR_DEF, LITERAL_FOR, LITERAL_WHILE, LITERAL_DO, STATIC_INIT, INSTANCE_INIT"/>
        </module>

        <!-- names -->
        <module name="PackageName">
            <property name="format" value="^[a-z][a-zA-Z0-9]*(\.[a-z][a-zA-Z0-9]*)*$"/>
        </module>
        <module name="TypeName">
            <property name="format" value="^[A-Z_][a-zA-Z0-9_]*$"/> <!-- underscore only in exceptional situations -->
        </module>
        <module name="ClassTypeParameterName">
            <property name="format" value="^([A-Z][A-Z0-9]*)|([A-Z][a-zA-Z0-9]*Type)$"/>
        </module>
        <module name="InterfaceTypeParameterName">
            <property name="format" value="^([A-Z][A-Z0-9]*)|([A-Z][a-zA-Z0-9]*Type)$"/>
        </module>
        <module name="ConstantName">
            <property name="format" value="^([A-Z][A-Z0-9]*(_[A-Z0-9]+)*)|(log)$"/>
        </module>
        <module name="StaticVariableName">
            <property name="format" value="^[a-z_][a-zA-Z0-9_]*$"/> <!-- underscore only in exceptional situations -->
        </module>
        <module name="MemberName">
            <property name="format" value="^[a-z_][a-zA-Z0-9_]*$"/> <!-- underscore only in exceptional situations -->
        </module>
        <module name="MethodName">
            <property name="format" value="^[a-z_][a-zA-Z0-9_]*$"/> <!-- underscore only in exceptional situations -->
        </module>
        <module name="MethodTypeParameterName">
            <property name="format" value="^([A-Z][A-Z0-9]*)|([A-Z][a-zA-Z0-9]*Type)$"/>
        </module>
        <module name="ParameterName">
            <property name="format" value="^[a-z_][a-zA-Z0-9_]*$"/> <!-- underscore only in exceptional situations -->
        </module>
        <module name="LocalVariableName">
            <property name="format" value="^[a-z_][a-zA-Z0-9_]*$"/> <!-- underscore only in exceptional situations -->
            <property name="allowOneCharVarInForLoop" value="true"/>
        </module>
        <module name="LocalFinalVariableName">
            <property name="format" value="^[a-z_][a-zA-Z0-9_]*$"/> <!-- underscore only in exceptional situations -->
        </module>

        <!-- whitespace -->
        <module name="NoLineWrap"/>
        <module name="NoWhitespaceBefore">
            <property name="allowLineBreaks" value="true"/>
        </module>
        <module name="NoWhitespaceAfter">
            <property name="allowLineBreaks" value="true"/>
        </module>
        <module name="WhitespaceAfter"/>
        <module name="WhitespaceAround">
            <property name="allowEmptyConstructors" value="true"/>
            <property name="ignoreEnhancedForColon" value="false"/>
        </module>
        <module name="EmptyLineSeparator">
            <property name="allowNoEmptyLineBetweenFields" value="true"/>
        </module>
        <module name="SeparatorWrap">
            <property name="tokens" value="DOT"/>
            <property name="option" value="nl"/>
        </module>
        <module name="SeparatorWrap">
            <property name="tokens" value="COMMA"/>
            <property name="option" value="eol"/>
        </module>
        <module name="OperatorWrap"/>
        <module name="GenericWhitespace"/>
        <module name="Indentation">
            <property name="arrayInitIndent" value="8"/>
        </module>
        <module name="MethodParamPad"/>
        <module name="ParenPad"/>
        <module name="TypecastParenPad"/>

        <!-- javadoc -->
        <module name="JavadocParagraph"/>
        <module name="AtclauseOrder"/>
        <module name="NonEmptyAtclauseDescription"/>
    </module>
</module>