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">

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

    <!-- 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"/>

    <!-- 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."/>
       <property name="severity" value="info"/>
    </module>

    <module name="TreeWalker">

        <!-- Checks for Javadoc comments.                     -->
        <!-- See http://checkstyle.sf.net/config_javadoc.html -->
        <module name="JavadocMethod">
          <property name="scope" value="public"/>
          <property name="allowMissingParamTags" value="true"/>
          <property name="allowMissingThrowsTags" value="true"/>
          <property name="allowMissingReturnTag" value="true"/>
          <property name="allowThrowsTagsForSubclasses" value="true"/>
          <property name="allowUndeclaredRTE" value="true"/>
          <property name="allowMissingPropertyJavadoc" value="true"/>
        </module>
        <module name="JavadocType">
          <property name="scope" value="package"/>
        </module>
        <module name="JavadocVariable">
          <property name="scope" value="package"/>
        </module>
        <module name="JavadocStyle">
          <property name="checkEmptyJavadoc" value="true"/>
        </module>

        <!-- 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">
          <!-- what is a good max value? -->
          <property name="max" value="100"/>
          <!-- ignore lines like "$File: //depot/... $" -->
          <property name="ignorePattern" value="\$File.*\$"/>
          <property name="severity" value="info"/>
        </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"/>
        <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"/>
        <module name="NeedBraces"/>
        <module name="RightCurly"/>


        <!-- Checks for common coding problems               -->
        <!-- See http://checkstyle.sf.net/config_coding.html -->
        <!-- <module name="AvoidInlineConditionals"/> -->
        <module name="DoubleCheckedLocking"/>    <!-- MY FAVOURITE -->
        <module name="EmptyStatement"/>
        <module name="EqualsHashCode"/>
        <module name="HiddenField">
          <property name="ignoreConstructorParameter" value="true"/>
          <property name="ignoreSetter" value="true"/>
          <property name="severity" value="warning"/>
        </module>
        <module name="IllegalInstantiation"/>
        <module name="InnerAssignment"/>
        <module name="MagicNumber">
          <property name="severity" value="warning"/>
        </module>
        <module name="MissingSwitchDefault"/>
        <!-- Problem with finding exception types... -->
        <module name="RedundantThrows">
          <property name="allowUnchecked" value="true"/>
          <property name="suppressLoadErrors" value="true"/>
          <property name="severity" value="info"/>
        </module>
        <module name="SimplifyBooleanExpression"/>
        <module name="SimplifyBooleanReturn"/>

        <!-- 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">
          <property name="protectedAllowed" value="true"/>
        </module>


        <!-- 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"/>
          <property name="severity" value="info"/>
        </module>
        <module name="UpperEll"/>

        <module name="FileContentsHolder"/> <!-- Required by comment suppression filters -->

    </module>

    <!-- Enable suppression comments -->
    <module name="SuppressionCommentFilter">
      <property name="offCommentFormat" value="CHECKSTYLE IGNORE\s+(\S+)"/>
      <property name="onCommentFormat" value="CHECKSTYLE END IGNORE\s+(\S+)"/>
      <property name="checkFormat" value="$1"/>
    </module>
    <module name="SuppressWithNearbyCommentFilter">
      <!-- Syntax is "SUPPRESS CHECKSTYLE name" -->
      <property name="commentFormat" value="SUPPRESS CHECKSTYLE (\w+)"/>
      <property name="checkFormat" value="$1"/>
      <property name="influenceFormat" value="1"/>
    </module>
</module>