src/main/config/checkstyle.xml

<?xml version="1.0" encoding="US-ASCII"?>
<!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="SuppressionFilter">-->
    <!--<property name="file" value="${basedir}/suppressions.xml"/>-->
    <!--</module>-->

    <!-- <module name="NewlineAtEndOfFile"/> doesn't work... -->
    <module name="Translation"/>
    <module name="FileLength"/>
    <module name="FileTabCharacter"/>

    <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."/>
    </module>

    <module name="RegexpHeader">
        <property name="headerFile" value="${checkstyle.header.file}"/>
        <property name="fileExtensions" value="java"/>
        <property name="id" value="header"/>
    </module>
    <!-- Checks for Size Violations.                    -->
    <!-- See http://checkstyle.sf.net/config_sizes.html -->
    <module name="LineLength">
        <property name="max" value="130"/>
    </module>
    <module name="TreeWalker">
        <module name="SuppressionCommentFilter">
            <property name="offCommentFormat" value="CSOFF\: ([\w\|]+)"/>
            <property name="onCommentFormat" value="CSON\: ([\w\|]+)"/>
            <property name="checkFormat" value="$1"/>
        </module>
        <module name="JavadocMethod"/>
        <module name="JavadocType"/>
        <module name="JavadocVariable"/>
        <module name="JavadocStyle"/>

        <!-- Checks for Naming Conventions.                  -->
        <!-- See http://checkstyle.sf.net/config_naming.html -->
        <module name="ConstantName">
            <property name="format" value="^(?:[A-Z][A-Z0-9]*(?:_[A-Z0-9]+)*)|(?:_log)$"/>
        </module>
        <module name="LocalFinalVariableName"/>
        <module name="LocalVariableName"/>
        <module name="MemberName">
            <property name="applyToPrivate" value="false"/>
            <property name="applyToProtected" value="false"/>
            <property name="applyToPackage" value="false"/>
        </module>
        <module name="MemberName">
            <property name="applyToPublic" value="false"/>
            <property name="format" value="^_[a-zA-Z][a-zA-Z0-9]*$"/>
        </module>
        <module name="MethodName"/>
        <module name="PackageName"/>
        <module name="ParameterName"/>
        <module name="StaticVariableName">
            <property name="applyToPrivate" value="false"/>
            <property name="applyToProtected" value="false"/>
            <property name="applyToPackage" value="false"/>
        </module>
        <module name="StaticVariableName">
            <property name="applyToPublic" value="false"/>
            <property name="format" value="^_[a-zA-Z][a-zA-Z0-9]*$"/>
        </module>
        <module name="TypeName"/>


        <!-- Checks for imports                              -->
        <!-- See http://checkstyle.sf.net/config_import.html -->
        <module name="AvoidStarImport"/>
        <module name="IllegalImport"/> <!-- defaults to sun.* packages -->
        <module name="RedundantImport"/>
        <module name="UnusedImports"/>
        <module name="ImportOrder">
            <property name="groups" value="java,javax"/>
            <property name="option" value="bottom"/>
        </module>

        <module name="MethodLength"/>
        <module name="ParameterNumber"/>


        <!-- Checks for whitespace                               -->
        <!-- See http://checkstyle.sf.net/config_whitespace.html -->
        <module name="EmptyForIteratorPad"/>
        <module name="GenericWhitespace"/>
        <module name="MethodParamPad"/>
        <!-- <module name="NoWhitespaceAfter"/> -->
        <!-- <module name="NoWhitespaceBefore"/> -->
        <module name="OperatorWrap">
            <property name="option" value="nl"/>
        </module>
        <module name="ParenPad"/>
        <module name="TypecastParenPad"/>
        <!-- <module name="WhitespaceAfter"/> -->
        <!-- <module name="WhitespaceAround"/> -->

        <!-- Modifier Checks                                    -->
        <!-- See http://checkstyle.sf.net/config_modifiers.html -->
        <module name="ModifierOrder"/>
        <module name="RedundantModifier"/>


        <!-- Checks for blocks. You know, those {}'s         -->
        <!-- See http://checkstyle.sf.net/config_blocks.html -->
        <module name="AvoidNestedBlocks"/>
        <module name="EmptyBlock">
            <property name="option" value="text"/>
        </module>
        <module name="LeftCurly">
            <property name="option" value="nlow"/>
        </module>
        <module name="NeedBraces"/>
        <module name="RightCurly"/>


        <!-- Checks for common coding problems               -->
        <!-- See http://checkstyle.sf.net/config_coding.html -->
        <!-- <module name="AvoidInlineConditionals"/> -->
        <module name="CovariantEquals"/>
        <module name="EmptyStatement"/>
        <module name="EqualsAvoidNull"/>
        <module name="EqualsHashCode"/>
        <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="RedundantThrows">
          <property name="allowUnchecked" value="true"/>
        </module-->
        <module name="SimplifyBooleanExpression"/>
        <module name="SimplifyBooleanReturn"/>
        <module name="NoFinalizer"/>
        <module name="SuperClone"/>
        <module name="IllegalCatch"/>
        <module name="IllegalThrows"/>
        <module name="PackageDeclaration"/>
        <module name="IllegalType">
            <property name="illegalClassNames"
                      value="java.util.GregorianCalendar,
                       java.util.Hashtable,
                       java.util.HashSet,
                       java.util.HashMap,
                       java.util.ArrayList,
                       java.util.LinkedHashMap,
                       java.util.LinkedHashSet,
                       java.util.TreeSet,
                       java.util.TreeMap,
                       java.util.Vector"/>

            <!-- java.util.LinkedList is allowed, since the Deque interface
            exposing useful methods like "removeLast" isn't available
            until 1.6 -->
        </module>
        <module name="ExplicitInitialization"/>
        <module name="FallThrough"/>

        <!-- Checks for class design                         -->
        <!-- See http://checkstyle.sf.net/config_design.html -->
        <!-- <module name="DesignForExtension"/> -->
        <module name="FinalClass"/>
        <module name="HideUtilityClassConstructor"/>
        <module name="InterfaceIsType"/>
        <!-- <module name="VisibilityModifier"/> -->

        <!-- Miscellaneous other checks.                   -->
        <!-- See http://checkstyle.sf.net/config_misc.html -->
        <module name="ArrayTypeStyle"/>
        <!-- module name="FinalParameters"/ -->
        <module name="Regexp">
            <!-- Do not allow System.out calls, use loggers instead -->
            <property name="format" value="System\s*\.\s*(out|err)"/>
            <property name="illegalPattern" value="true"/>
            <property name="ignoreComments" value="true"/>
            <property name="message" value="System.out or System.err (use Logger instead)"/>
        </module>
        <module name="Regexp">
            <!-- Do not allow printStackTrace, use loggers or rethrow -->
            <property name="format" value="\.\s*printStackTrace\s*\(\s*\)"/>
            <property name="illegalPattern" value="true"/>
            <property name="ignoreComments" value="true"/>
            <property name="message" value="printStackTrace() (use Logger or rethrow)"/>
        </module>

        <!-- TODO: add this back: <module name="TodoComment"/> -->
        <module name="UpperEll"/>
        <module name="Indentation">
            <property name="caseIndent" value="4"/>
        </module>

    </module>

</module>