src/main/config/checkstyle.xml

<?xml version="1.0"?>
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 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
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 * distributed under the License is distributed on an "AS IS" BASIS,
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 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
 -->

<!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.2//EN"
                        "http://www.puppycrawl.com/dtds/configuration_1_2.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">

    <!-- Checks that a package.html file exists for each package.     -->
    <!-- See http://checkstyle.sf.net/config_javadoc.html#PackageHtml -->
    <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 -->
    <!-- JEXL-20: tried every combination on a Mac to no avail...
    <module name="NewlineAtEndOfFile">
        <property name="lineSeparator" value="lf"/>
    </module>
    -->

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


    <!-- Checks for Headers                              -->
    <!-- See http://checkstyle.sf.net/config_header.html -->
    <module name="Header">
        <!-- The follow property value demonstrates the ability     -->
        <!-- to have access to ANT properties. In this case it uses -->
        <!-- the ${basedir} property to allow Checkstyle to be run  -->
        <!-- from any directory within a project. See property      -->
        <!-- expansion,                                             -->
        <!-- http://checkstyle.sf.net/config.html#properties        -->
        <!-- <property                                              -->
        <!--     name="headerFile"                                  -->
        <!--     value="${basedir}/java.header"/>                   -->
        <property name="headerFile" value="${checkstyle.header.file}"/>
        <property name="ignoreLines" value="2"/>
        <property name="fileExtensions" value="java,xml"/>
    </module>
               
    <!-- See http://checkstyle.sf.net/config_sizes.html -->
    <module name="FileLength"/>

    <module name="TreeWalker">

        <property name="cacheFile" value="${checkstyle.cache.file}"/>

        <!-- Checks for Javadoc comments.                     -->
        <!-- See http://checkstyle.sf.net/config_javadoc.html -->
        <!-- JEXL-20: many of those by API choice -->
        <module name="JavadocMethod">
           <property name="allowUndeclaredRTE" value="true"/>
        </module>
        <module name="JavadocType"/>
        <module name="JavadocVariable"/>
        <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"/>
        <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">
            <!--  JEXL: added max, ignore @version and @see -->
            <property name="max" value="120"/>
            <property name="ignorePattern" value="@version"/>
            <property name="ignorePattern" value="@see"/>
        </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="NoWhitespaceAfter"/> -->
        <!-- <module name="NoWhitespaceBefore"/> -->
        <!-- <module name="WhitespaceAfter"/> -->
        <!-- <module name="WhitespaceAround"/> -->
        <module name="OperatorWrap"/>
        <module name="ParenPad"/>
        <module name="TypecastParenPad"/>


        <!-- Modifier Checks                                    -->
        <!-- See http://checkstyle.sf.net/config_modifiers.html -->
        <module name="ModifierOrder"/>
        <!-- too agressive 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 -->
        <!-- JEXL: module name="AvoidInlineConditionals"/-->
        <module name="EmptyStatement"/>
        <module name="EqualsHashCode"/>
        <module name="HiddenField"/>
        <module name="IllegalInstantiation"/>
        <module name="InnerAssignment"/>
        <module name="MagicNumber">
            <property name="ignoreNumbers" value="-1, 0, 1, 2, 3"/>
        </module>
        <module name="MissingSwitchDefault"/>
        <!-- JEXL-20: used in introspection -->
        <!--<module name="RedundantThrows"/>-->
        <module name="SimplifyBooleanExpression"/>
        <module name="SimplifyBooleanReturn"/>

        <!-- Checks for class design                         -->
        <!-- See http://checkstyle.sf.net/config_design.html -->
        <!-- JEXL: module name="DesignForExtension"/-->
        <!-- JEXL: module name="FinalClass"/-->
        <!-- JEXL: module name="HideUtilityClassConstructor"/-->
        <module name="InterfaceIsType"/>
        <module name="VisibilityModifier">
            <property name="packageAllowed" value="true"/>
            <property name="protectedAllowed" value="false"/>
        </module>


        <!-- Miscellaneous other checks.                   -->
        <!-- See http://checkstyle.sf.net/config_misc.html -->
        <module name="ArrayTypeStyle"/>
        <!-- JEXL: module name="FinalParameters"/-->
        <!-- JEXL: module name="GenericIllegalRegexp">
            <property name="format" value="\s+$"/>
            <property name="message" value="Line has trailing spaces."/>
        </module-->
        <!--module name="TodoComment"/-->
        <module name="UpperEll"/>
        
        <!-- used for suppression comment filter -->
        <module name="FileContentsHolder"/>
    </module>

    <module name="SuppressionCommentFilter">
        <property name="offCommentFormat" value="CSOFF\: ([\w\|]+)"/>
        <property name="onCommentFormat" value="CSON\: ([\w\|]+)"/>
        <property name="checkFormat" value="$1"/>
    </module>

</module>