checkstyle.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.3//EN" "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">
<!--
  Checkstyle configuration that checks the sun coding conventions from:
    - the Java Language Specification at
      http://java.sun.com/docs/books/jls/second_edition/html/index.html
    - the Sun Code Conventions at http://java.sun.com/docs/codeconv/
    - the Javadoc guidelines at
      http://java.sun.com/j2se/javadoc/writingdoccomments/index.html
    - the JDK Api documentation http://java.sun.com/j2se/docs/api/index.html
    - some best practices
  Checkstyle is very configurable. Be sure to read the documentation at
  http://checkstyle.sf.net (or in your downloaded distribution).
  Most Checks are configurable, be sure to consult the documentation.
  To completely disable a check, just comment it out or delete it from the file.
  Finally, it is worth reading the documentation.
-->

<module name="Checker">
    <!-- While Maven supports passing Suppression file information in parameters,
         Intellij's Checkstyle-IDEA plugin only appears to support suppressions
         in checkstyle.xml configuration file, we're configuring the suppression
         file here -->
    <module name="SuppressionFilter">
        <property name="file" value="suppressions.xml"/>
        <property name="optional" value="false"/>
    </module>

    <!-- Enable suppression with @SuppressWarnings annotations -->
    <module name="SuppressWarningsFilter" />

    <!--
        If you set the basedir property below, then all reported file
        names will be relative to the specified directory. See
        http://checkstyle.sourceforge.net/5.x/config.html#Checker
        <property name="basedir" value="${basedir}"/>
    -->

    <!-- Checks that a package-info.java file exists for each package.     -->
    <!-- See http://checkstyle.sf.net/config_javadoc.html#JavadocPackage -->
    <module name="JavadocPackage"/>

    <!-- Checks whether files end with a new line.                        -->
    <!-- See http://checkstyle.sf.net/config_misc.html#NewlineAtEndOfFile -->
    <module name="NewlineAtEndOfFile"/>

    <!-- Checks that property files contain the same keys.         -->
    <!-- See http://checkstyle.sf.net/config_misc.html#Translation -->
    <module name="Translation"/>

    <!-- Checks for Size Violations.                    -->
    <!-- See http://checkstyle.sf.net/config_sizes.html -->
    <module name="FileLength">
        <property name="max" value="2500"/>
    </module>

    <!-- Checks for whitespace                               -->
    <!-- See http://checkstyle.sf.net/config_whitespace.html -->
    <module name="FileTabCharacter"/>

    <!-- Miscellaneous other checks.                   -->
    <!-- See http://checkstyle.sf.net/config_misc.html -->
    <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="TreeWalker">
        <!-- Make annotations available for filtering via SuppressWarningsFilter -->
        <module name="SuppressWarningsHolder" />

        <module name="SuppressWithNearbyCommentFilter">
            <property name="commentFormat" value="checkstyle"/>
            <property name="checkFormat" value=".*"/>
            <property name="influenceFormat" value="0"/>
        </module>

        <!-- Checks for Javadoc comments.                     -->
        <!-- See http://checkstyle.sf.net/config_javadoc.html -->
        <!--TODO: restore javadoc warnings once we're further along-->
        <!--<module name="JavadocMethod">-->
            <!--<property name="allowUndeclaredRTE" value="true"/>-->
            <!--<property name="allowThrowsTagsForSubclasses" value="true"/>-->
            <!--<property name="suppressLoadErrors" value="true"/>-->
            <!--<property name="allowMissingPropertyJavadoc" value="true"/>-->
            <!--<property name="excludeScope" value="private"/>-->
            <!--<property name="ignoreMethodNamesRegex" value="^.*Exception$" />-->
        <!--</module>-->
        <!--<module name="JavadocType" />-->
        <!--<module name="JavadocVariable">-->
            <!--<property name="ignoreNamePattern" value="LOG" />-->
            <!--<property name="scope" value="public" />-->
        <!--</module>-->
        <!--<module name="JavadocStyle" />-->

        <!-- Checks for Naming Conventions.                  -->
        <!-- See http://checkstyle.sf.net/config_naming.html -->
        <module name="ConstantName" />
        <module name="LocalFinalVariableName" />
        <module name="LocalVariableName" />
        <module name="MemberName"/>
        <module name="MethodName" />
        <module name="PackageName" />
        <module name="ParameterName" />
        <module name="StaticVariableName" />
        <module name="TypeName" />

        <!-- Checks for imports                              -->
        <!-- See http://checkstyle.sf.net/config_import.html -->
        <module name="AvoidStarImport">
            <property name="allowStaticMemberImports" value="true"/>
        </module>
        <module name="IllegalImport"/> <!-- defaults to sun.* packages -->
        <module name="RedundantImport"/>
        <module name="UnusedImports"/>

        <!-- Checks for Size Violations.                    -->
        <!-- See http://checkstyle.sf.net/config_sizes.html -->
        <module name="LineLength">
            <property name="max" value="140" />
            <property name="tabWidth" value="4" />
        </module>
        <module name="MethodLength" />
        <module name="ParameterNumber" />

        <!-- Finds methods missing the @Override annotation -->
        <module name="MissingOverride" />

        <!-- 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="eol"/>
        </module>
        <module name="ParenPad"/>
        <module name="TypecastParenPad"/>
        <module name="WhitespaceAfter">
            <property name="tokens" value="COMMA, SEMI"/>
        </module>
        <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"/>
        <module name="LeftCurly"/>
        <module name="NeedBraces">
            <property name="allowSingleLineStatement" value="true"/>
            <property name="allowEmptyLoopBody" value="true" />
        </module>

        <module name="RightCurly"/>

        <!-- Checks for common coding problems               -->
        <!-- See http://checkstyle.sf.net/config_coding.html -->
        <!-- Disagree with AvoidInlineConditionals; we mostly use them in .equals methods and
             they increase readability in those contexts. May be worth revisiting if there's
             a version of this that allows single-line ternary operators but scolds you for
             complicated ones. -->
        <!--<module name="AvoidInlineConditionals"/>-->
        <module name="EmptyStatement"/>
        <module name="EqualsHashCode"/>
        <!-- Disabling this check because it doesn't understand fluent
             setters. -->
        <module name="HiddenField">
            <property name="ignoreSetter" value="true" />
            <property name="ignoreConstructorParameter" value="true" />
            <property name="setterCanReturnItsClass" value="true"/>
        </module>
        <module name="IllegalInstantiation"/>
        <module name="InnerAssignment"/>
        <module name="MagicNumber">
            <property name="constantWaiverParentToken" value="ASSIGN, ARRAY_INIT, EXPR, UNARY_PLUS, UNARY_MINUS, TYPECAST, ELIST, LITERAL_NEW, METHOD_CALL, STAR, DIV, PLUS, MINUS, SL,SR" />
        </module>
        <module name="MissingSwitchDefault"/>
        <module name="SimplifyBooleanExpression"/>
        <module name="SimplifyBooleanReturn"/>

        <!-- Checks for class design                         -->
        <!-- See http://checkstyle.sf.net/config_design.html -->
        <!-- This rule disallows an abstract class from having any behavior,
             so we turned it off. -->
        <!--<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="TodoComment">
            <property name="format" value="(TODO)|(FIXME)|(XXX)"/>
        </module>
        <module name="UpperEll" />
    </module>
</module>