checkstyle.xml

<?xml version="1.0"?>
<!--
/*
// Copyright (c) 2015 Intel Corporation 
//
// Licensed 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
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
*/
-->
<!--
  This version of checkstyle is based on the Hadoop and common-math
  checkstyle configurations.  It is a best effort attempt to try to match
  the CODE_CONVENTIONS and Oracle "Code Conventions for the Java
  Programming Language".  See the following link:
  
  http://www.oracle.com/technetwork/java/codeconvtoc-136057.html

  The documentation for checkstyle is available at 

  http://checkstyle.sourceforge.net 
-->

<!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.1//EN" "http://www.puppycrawl.com/dtds/configuration_1_1.dtd">

<module name="Checker">
  <property name="localeLanguage" value="en"/>

  <!-- Checks for headers -->
  <!-- See http://checkstyle.sf.net/config_header.html -->
    <!-- Verify that EVERY source file has the appropriate license -->
  <module name="Header">
    <property name="headerFile" value="${checkstyle.header.file}"/>
  </module>

  <!-- Checks for Javadoc comments (checker).           -->
  <!-- See http://checkstyle.sf.net/config_javadoc.html -->
    <!-- Require package javadoc -->
  <module name="JavadocPackage"/>

  <!-- Miscellaneous other checks (checker).         -->
  <!-- See http://checkstyle.sf.net/config_misc.html -->
    <!-- Require files to end with newline characters -->
  <module name="NewlineAtEndOfFile"/>

  <!-- Checks for whitespace (tree walker)                 -->
  <!-- See http://checkstyle.sf.net/config_whitespace.html -->
    <!-- No tabs allowed! -->
  <module name="FileTabCharacter"/>

  <module name="TreeWalker">
    <property name="cacheFile" value="target/checkstyle-cachefile"/>

    <!-- Checks for blocks. You know, those {}'s         -->
    <!-- See http://checkstyle.sf.net/config_blocks.html -->
      <!-- No empty blocks (i.e. catch) -->
    <module name="EmptyBlock"/>
    <module name="AvoidNestedBlocks"/>
    <module name="LeftCurly"/>
      <!-- No if/else/do/for/while without braces -->
    <module name="NeedBraces"/>
    <module name="RightCurly"/>

    <!-- Checks for class design                         -->
    <!-- See http://checkstyle.sf.net/config_design.html -->
      <!-- Utility class should not be instantiated, they must have a
	   private constructor -->
    <module name="HideUtilityClassConstructor"/>
      <!-- Interfaces must be types (not just constants) -->
    <module name="InterfaceIsType"/>
      <!-- No public fields -->
    <module name="VisibilityModifier">
       <property name="protectedAllowed" value="true"/>
       <property name="publicMemberPattern" value="^$"/>
    </module>

    <!-- Checks for common coding problems               -->
    <!-- See http://checkstyle.sf.net/config_coding.html -->
    <module name="EmptyStatement"/>
      <!-- Require hash code override when equals is -->
    <module name="EqualsHashCode"/>
      <!-- Method parameters and local variables should not hide
	   fields, except in constructors and setters -->
    <module name="HiddenField">
      <property name="ignoreConstructorParameter" value="true" />
      <property name="ignoreSetter" value="true" />
      <property name="tokens" value="VARIABLE_DEF"/>
    </module>
      <!-- Disallow unnecessary instantiation of Boolean, String -->
    <module name="IllegalInstantiation">
      <property name="classes" value="java.lang.Boolean, java.lang.String"/>
    </module>
    <module name="InnerAssignment"/>
      <!-- Switch statements should be complete and with independent cases -->
    <module name="FallThrough" />
    <module name="MissingSwitchDefault" />
    <!-- For hadoop_yarn profile, some YARN exceptions aren't loading in checkstyle -->
    <module name="RedundantThrows">
        <property name="suppressLoadErrors" value="true" />
    </module>
    <module name="SimplifyBooleanExpression"/>
    <module name="SimplifyBooleanReturn"/>
      <!-- Only one statment per line allowed -->
    <module name="OneStatementPerLine"/>
      <!-- Use a consistent way to put declarations -->
    <module name="DeclarationOrder" />
      <!-- Don't add up parentheses when they are not required -->
    <module name="UnnecessaryParentheses" />
      <!-- Don't use too widespread catch (Exception, Throwable,
	   RuntimeException) --> 
    <module name="IllegalCatch" />
      <!-- Don't use = or != for string comparisons -->
    <module name="StringLiteralEquality" />
      <!-- Don't declare multiple variables in the same statement -->
    <module name="MultipleVariableDeclarations" />
      <!-- String literals more than one character long should not be 
	   repeated several times -->
      <!-- the "unchecked" string is also accepted to allow
	   @SuppressWarnings("unchecked") -->
      <!-- Disabling for now until we have a better ignoreStringsRegexp -->
      <!--
    <module name="MultipleStringLiterals" >
      <property name="ignoreStringsRegexp" value='^(("")|(".")|("unchecked"))$'/>
    </module>
      -->

    <!-- Checks for imports                              -->
    <!-- See http://checkstyle.sf.net/config_import.html -->
    <module name="RedundantImport"/>
      <!-- Import should be explicit, really needed and only from pure
	   java packages --> 
    <module name="AvoidStarImport" />
    <module name="UnusedImports" />
    <module name="IllegalImport" />

    <!-- Checks for Javadoc comments (tree walker).       -->
    <!-- See http://checkstyle.sf.net/config_javadoc.html -->
      <!-- Javadoc must be formatted correctly -->
    <module name="JavadocStyle">
      <property name="checkFirstSentence" value="false"/>
    </module>
      <!-- Must have class / interface header comments -->
    <module name="JavadocType"/>
      <!-- Require method javadocs, allow undeclared RTE, allow missing 
	   javadoc on getters and setters  -->
    <module name="JavadocMethod">
      <property name="allowUndeclaredRTE" value="true"/>
      <property name="allowMissingThrowsTags" value="true"/> 
      <property name="allowMissingPropertyJavadoc" value="true"/>
    </module>
      <!-- Require field javadoc -->
    <module name="JavadocVariable"/>   

    <!-- Miscellaneous other checks (tree walker).     -->
    <!-- See http://checkstyle.sf.net/config_misc.html -->
      <!-- Java style arrays -->
    <module name="ArrayTypeStyle"/>
      <!-- Indentation -->
    <module name="Indentation">
      <property name="caseIndent" value="0"/>
      <property name="basicOffset" value="4"/>
      <property name="braceAdjustment" value="0"/>
    </module>
      <!-- Turn this on to see what needs to be done
    <module name="TodoComment"/>
       -->
    <module name="UpperEll"/>

    <!-- Modifier Checks                                    -->
    <!-- See http://checkstyle.sf.net/config_modifiers.html -->
      <!-- Use a consistent way to put modifiers -->
    <module name="ModifierOrder"/>
    <module name="RedundantModifier"/>

    <!-- Checks for Naming Conventions.                  -->
    <!-- See http://checkstyle.sf.net/config_naming.html -->
      <!-- Constant names should obey the traditional all uppercase 
	   naming convention -->
    <module name="ConstantName"/>
    <module name="LocalFinalVariableName"/>
    <module name="LocalVariableName"/>
    <module name="MemberName"/>
    <module name="MethodName"/>
    <module name="PackageName"/>
    <module name="ParameterName"/>
    <module name="StaticVariableName">
      <property name="format" value="^[A-Z0-9_]*$"/>
    </module>
    <module name="TypeName"/>

    <!-- Checks for regexp expressions.                  -->
    <!-- See http://checkstyle.sf.net/config_regexp.html -->    
      <!-- No trailing whitespace -->
    <module name="Regexp">
      <property name="format" value="[ \t]+$"/>
      <property name="illegalPattern" value="true"/>
      <property name="message" value="Trailing whitespace"/>
    </module> 
      <!-- No System.out.println() statements -->
    <module name="Regexp">
      <!-- No sysouts -->
      <property name="format" value="System\.out\.println"/>
      <property name="illegalPattern" value="true"/>
    </module>
      <!-- Authors should be in pom.xml file -->
    <module name="Regexp">
      <property name="format" value="@author"/>
      <property name="illegalPattern" value="true"/>
      <property name="message" value="developers names should be in pom file"/>
    </module>

    <!-- Checks for Size Violations.                    -->
    <!-- See http://checkstyle.sf.net/config_sizes.html -->
      <!-- Lines cannot exceed 120 chars -->
    <module name="LineLength">
      <property name="max" value="120"/>
      <property name="ignorePattern" value="^import"/>
    </module>
      <!-- Over time, we will revised this down -->
    <module name="MethodLength">
      <property name="max" value="200"/>
    </module>
    <module name="ParameterNumber">
      <property name="max" value="8"/>
    </module>

    <!-- Checks for whitespace (tree walker)                 -->
    <!-- See http://checkstyle.sf.net/config_whitespace.html -->
    <module name="EmptyForIteratorPad"/>
      <!-- Spacing around methods -->
    <module name="MethodParamPad">
      <property name="option" value="nospace"/>
      <property name="allowLineBreaks" value="true"/>
     </module>
      <!-- No whitespace before a token -->
    <module name="NoWhitespaceBefore"/>
      <!-- Whitespace after tokens is required -->
    <module name="WhitespaceAfter"/>
      <!-- Whitespace around tokens is required -->
    <module name="WhitespaceAround"/>
    <module name="ParenPad"/>
    <module name="TypecastParenPad"/>
      <!-- No extra whitespace around types -->
    <module name="GenericWhitespace"/>
    <!-- Operator must be at end of wrapped line -->
    <module name="OperatorWrap">
      <property name="option" value="eol"/>
    </module>

    <!-- Required for SuppressionCommentFilter below -->
    <module name="FileContentsHolder"/>
  </module>
  
  <!-- Setup special comments to suppress specific checks from source files -->
  <module name="SuppressionCommentFilter">
    <property name="offCommentFormat" value="CHECKSTYLE\: stop ([\w\|]+)"/>
    <property name="onCommentFormat"  value="CHECKSTYLE\: resume ([\w\|]+)"/>
    <property name="checkFormat"      value="$1"/>
  </module>
</module>