From 2d7363b27360e36fdd62546c0f9d0b1d78133f29 Mon Sep 17 00:00:00 2001
From: Jonathan Eagles <jeagles@gmail.com>
Date: Fri, 1 May 2015 13:11:50 -0500
Subject: [PATCH] HADOOP-11889. Make checkstyle runnable from root project
 (Gera Shegalov via jeagles)

---
 hadoop-build-tools/pom.xml                    |  28 +++
 .../checkstyle-noframes-sorted.xsl            |   0
 .../main/resources/checkstyle}/checkstyle.xml |   5 +-
 .../checkstyle-noframes-sorted.xsl            | 178 ------------------
 .../hadoop-hdfs/dev-support/checkstyle.xml    | 169 -----------------
 hadoop-project-dist/pom.xml                   |  11 --
 hadoop-project/pom.xml                        |   6 -
 .../hadoop-azure/src/config/checkstyle.xml    |   1 -
 hadoop-tools/hadoop-distcp/pom.xml            |   7 -
 pom.xml                                       |  32 ++++
 10 files changed, 63 insertions(+), 374 deletions(-)
 create mode 100644 hadoop-build-tools/pom.xml
 rename {hadoop-common-project/hadoop-common/src/test => hadoop-build-tools/src/main/resources/checkstyle}/checkstyle-noframes-sorted.xsl (100%)
 rename {hadoop-common-project/hadoop-common/dev-support => hadoop-build-tools/src/main/resources/checkstyle}/checkstyle.xml (98%)
 delete mode 100644 hadoop-hdfs-project/hadoop-hdfs/dev-support/checkstyle-noframes-sorted.xsl
 delete mode 100644 hadoop-hdfs-project/hadoop-hdfs/dev-support/checkstyle.xml

diff --git a/hadoop-build-tools/pom.xml b/hadoop-build-tools/pom.xml
new file mode 100644
index 0000000000..1931072aff
--- /dev/null
+++ b/hadoop-build-tools/pom.xml
@@ -0,0 +1,28 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  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. See accompanying LICENSE file.
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<parent>
+  <artifactId>hadoop-main</artifactId>
+  <groupId>org.apache.hadoop</groupId>
+  <version>3.0.0-SNAPSHOT</version>
+</parent>
+<modelVersion>4.0.0</modelVersion>
+
+<artifactId>hadoop-build-tools</artifactId>
+  <description>Apache Hadoop Build Tools Project</description>
+  <name>Apache Hadoop Build Tools</name>
+</project>
\ No newline at end of file
diff --git a/hadoop-common-project/hadoop-common/src/test/checkstyle-noframes-sorted.xsl b/hadoop-build-tools/src/main/resources/checkstyle/checkstyle-noframes-sorted.xsl
similarity index 100%
rename from hadoop-common-project/hadoop-common/src/test/checkstyle-noframes-sorted.xsl
rename to hadoop-build-tools/src/main/resources/checkstyle/checkstyle-noframes-sorted.xsl
diff --git a/hadoop-common-project/hadoop-common/dev-support/checkstyle.xml b/hadoop-build-tools/src/main/resources/checkstyle/checkstyle.xml
similarity index 98%
rename from hadoop-common-project/hadoop-common/dev-support/checkstyle.xml
rename to hadoop-build-tools/src/main/resources/checkstyle/checkstyle.xml
index 4caa03f05d..de7319c9e1 100644
--- a/hadoop-common-project/hadoop-common/dev-support/checkstyle.xml
+++ b/hadoop-build-tools/src/main/resources/checkstyle/checkstyle.xml
@@ -114,7 +114,9 @@
 
         <!-- Checks for Size Violations.                    -->
         <!-- See http://checkstyle.sf.net/config_sizes.html -->
-        <module name="LineLength"/>
+        <module name="LineLength">
+          <property name="ignorePattern" value="^import"/>
+        </module>
         <module name="MethodLength"/>
         <module name="ParameterNumber"/>
 
@@ -158,7 +160,6 @@
         <module name="IllegalInstantiation"/>
         <module name="InnerAssignment"/>
         <module name="MissingSwitchDefault"/>
-        <module name="RedundantThrows"/>
         <module name="SimplifyBooleanExpression"/>
         <module name="SimplifyBooleanReturn"/>
 
diff --git a/hadoop-hdfs-project/hadoop-hdfs/dev-support/checkstyle-noframes-sorted.xsl b/hadoop-hdfs-project/hadoop-hdfs/dev-support/checkstyle-noframes-sorted.xsl
deleted file mode 100644
index 5f9e93ba27..0000000000
--- a/hadoop-hdfs-project/hadoop-hdfs/dev-support/checkstyle-noframes-sorted.xsl
+++ /dev/null
@@ -1,178 +0,0 @@
-<xsl:stylesheet	xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
-<xsl:output method="html" indent="yes"/>
-<xsl:decimal-format decimal-separator="." grouping-separator="," />
-
-<xsl:key name="files" match="file" use="@name" />
-
-<!-- Checkstyle XML Style Sheet by Stephane Bailliez <sbailliez@apache.org>         -->
-<!-- Part of the Checkstyle distribution found at http://checkstyle.sourceforge.net -->
-<!-- Usage (generates checkstyle_report.html):                                      -->
-<!--    <checkstyle failonviolation="false" config="${check.config}">               -->
-<!--      <fileset dir="${src.dir}" includes="**/*.java"/>                          -->
-<!--      <formatter type="xml" toFile="${doc.dir}/checkstyle_report.xml"/>         -->
-<!--    </checkstyle>                                                               -->
-<!--    <style basedir="${doc.dir}" destdir="${doc.dir}"                            -->
-<!--            includes="checkstyle_report.xml"                                    -->
-<!--            style="${doc.dir}/checkstyle-noframes-sorted.xsl"/>                 -->
-
-<xsl:template match="checkstyle">
-	<html>
-		<head>
-		<style type="text/css">
-    .bannercell {
-      border: 0px;
-      padding: 0px;
-    }
-    body {
-      margin-left: 10;
-      margin-right: 10;
-      font:normal 80% arial,helvetica,sanserif;
-      background-color:#FFFFFF;
-      color:#000000;
-    }
-    .a td {
-      background: #efefef;
-    }
-    .b td {
-      background: #fff;
-    }
-    th, td {
-      text-align: left;
-      vertical-align: top;
-    }
-    th {
-      font-weight:bold;
-      background: #ccc;
-      color: black;
-    }
-    table, th, td {
-      font-size:100%;
-      border: none
-    }
-    table.log tr td, tr th {
-
-    }
-    h2 {
-      font-weight:bold;
-      font-size:140%;
-      margin-bottom: 5;
-    }
-    h3 {
-      font-size:100%;
-      font-weight:bold;
-      background: #525D76;
-      color: white;
-      text-decoration: none;
-      padding: 5px;
-      margin-right: 2px;
-      margin-left: 2px;
-      margin-bottom: 0;
-    }
-		</style>
-		</head>
-		<body>
-			<a name="top"></a>
-      <!-- jakarta logo -->
-      <table border="0" cellpadding="0" cellspacing="0" width="100%">
-      <tr>
-        <td class="bannercell" rowspan="2">
-          <!--a href="http://jakarta.apache.org/">
-          <img src="http://jakarta.apache.org/images/jakarta-logo.gif" alt="http://jakarta.apache.org" align="left" border="0"/>
-          </a-->
-        </td>
-    		<td class="text-align:right"><h2>CheckStyle Audit</h2></td>
-    		</tr>
-    		<tr>
-    		<td class="text-align:right">Designed for use with <a href='http://checkstyle.sourceforge.net/'>CheckStyle</a> and <a href='http://jakarta.apache.org'>Ant</a>.</td>
-    		</tr>
-      </table>
-    	<hr size="1"/>
-
-			<!-- Summary part -->
-			<xsl:apply-templates select="." mode="summary"/>
-			<hr size="1" width="100%" align="left"/>
-
-			<!-- Package List part -->
-			<xsl:apply-templates select="." mode="filelist"/>
-			<hr size="1" width="100%" align="left"/>
-
-			<!-- For each package create its part -->
-            <xsl:apply-templates select="file[@name and generate-id(.) = generate-id(key('files', @name))]" />
-
-			<hr size="1" width="100%" align="left"/>
-
-
-		</body>
-	</html>
-</xsl:template>
-
-
-
-	<xsl:template match="checkstyle" mode="filelist">
-		<h3>Files</h3>
-		<table class="log" border="0" cellpadding="5" cellspacing="2" width="100%">
-      <tr>
-        <th>Name</th>
-        <th>Errors</th>
-      </tr>
-          <xsl:for-each select="file[@name and generate-id(.) = generate-id(key('files', @name))]">
-                <xsl:sort data-type="number" order="descending" select="count(key('files', @name)/error)"/>
-				<xsl:variable name="errorCount" select="count(error)"/>
-				<tr>
-          <xsl:call-template name="alternated-row"/>
-					<td><a href="#f-{@name}"><xsl:value-of select="@name"/></a></td>
-					<td><xsl:value-of select="$errorCount"/></td>
-				</tr>
-			</xsl:for-each>
-		</table>
-	</xsl:template>
-
-
-	<xsl:template match="file">
-    <a name="f-{@name}"></a>
-    <h3>File <xsl:value-of select="@name"/></h3>
-
-    <table class="log" border="0" cellpadding="5" cellspacing="2" width="100%">
-    	<tr>
-    	  <th>Error Description</th>
-    	  <th>Line</th>
-      </tr>
-        <xsl:for-each select="key('files', @name)/error">
-          <xsl:sort data-type="number" order="ascending" select="@line"/>
-    	<tr>
-        <xsl:call-template name="alternated-row"/>
-    	  <td><xsl:value-of select="@message"/></td>
-    	  <td><xsl:value-of select="@line"/></td>
-    	</tr>
-    	</xsl:for-each>
-    </table>
-    <a href="#top">Back to top</a>
-	</xsl:template>
-
-
-	<xsl:template match="checkstyle" mode="summary">
-		<h3>Summary</h3>
-        <xsl:variable name="fileCount" select="count(file[@name and generate-id(.) = generate-id(key('files', @name))])"/>
-		<xsl:variable name="errorCount" select="count(file/error)"/>
-		<table class="log" border="0" cellpadding="5" cellspacing="2" width="100%">
-		<tr>
-			<th>Files</th>
-			<th>Errors</th>
-		</tr>
-		<tr>
-		  <xsl:call-template name="alternated-row"/>
-			<td><xsl:value-of select="$fileCount"/></td>
-			<td><xsl:value-of select="$errorCount"/></td>
-		</tr>
-		</table>
-	</xsl:template>
-
-  <xsl:template name="alternated-row">
-    <xsl:attribute name="class">
-      <xsl:if test="position() mod 2 = 1">a</xsl:if>
-      <xsl:if test="position() mod 2 = 0">b</xsl:if>
-    </xsl:attribute>
-  </xsl:template>
-</xsl:stylesheet>
-
-
diff --git a/hadoop-hdfs-project/hadoop-hdfs/dev-support/checkstyle.xml b/hadoop-hdfs-project/hadoop-hdfs/dev-support/checkstyle.xml
deleted file mode 100644
index eda4a47163..0000000000
--- a/hadoop-hdfs-project/hadoop-hdfs/dev-support/checkstyle.xml
+++ /dev/null
@@ -1,169 +0,0 @@
-<?xml version="1.0"?>
-<!DOCTYPE module PUBLIC
-    "-//Puppy Crawl//DTD Check Configuration 1.2//EN"
-    "http://www.puppycrawl.com/dtds/configuration_1_2.dtd">
-
-<!--
-
-  Checkstyle configuration for Hadoop that is based on the sun_checks.xml file
-  that is bundled with Checkstyle and includes checks for:
-
-    - 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"/>
-
-    <!-- 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"/>
-
-    <module name="FileLength"/>
-    <module name="FileTabCharacter"/>
-
-    <module name="TreeWalker">
-
-        <!-- Checks for Javadoc comments.                     -->
-        <!-- See http://checkstyle.sf.net/config_javadoc.html -->
-        <module name="JavadocType">
-          <property name="scope" value="public"/>
-          <property name="allowMissingParamTags" value="true"/>
-        </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 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"/>                   -->
-        <!-- </module> -->
-
-        <!-- Following interprets the header file as regular expressions. -->
-        <!-- <module name="RegexpHeader"/>                                -->
-
-
-        <!-- Checks for imports                              -->
-        <!-- See http://checkstyle.sf.net/config_import.html -->
-        <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"/>
-        <module name="MethodLength"/>
-        <module name="ParameterNumber"/>
-
-
-        <!-- Checks for whitespace                               -->
-        <!-- See http://checkstyle.sf.net/config_whitespace.html -->
-        <module name="EmptyForIteratorPad"/>
-        <module name="MethodParamPad"/>
-        <module name="NoWhitespaceAfter"/>
-        <module name="NoWhitespaceBefore"/>
-        <module name="ParenPad"/>
-        <module name="TypecastParenPad"/>
-        <module name="WhitespaceAfter">
-	    	<property name="tokens" value="COMMA, SEMI"/>
-		</module>
-
-
-        <!-- 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"/>
-        <module name="RightCurly"/>
-
-
-        <!-- Checks for common coding problems               -->
-        <!-- See http://checkstyle.sf.net/config_coding.html -->
-        <!-- module name="AvoidInlineConditionals"/-->
-        <module name="EmptyStatement"/>
-        <module name="EqualsHashCode"/>
-        <module name="HiddenField">
-          <property name="ignoreConstructorParameter" value="true"/>
-        </module>
-        <module name="IllegalInstantiation"/>
-        <module name="InnerAssignment"/>
-        <module name="MissingSwitchDefault"/>
-        <module name="RedundantThrows"/>
-        <module name="SimplifyBooleanExpression"/>
-        <module name="SimplifyBooleanReturn"/>
-
-        <!-- Checks for class design                         -->
-        <!-- See http://checkstyle.sf.net/config_design.html -->
-        <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="Indentation">
-            <property name="basicOffset" value="2" />
-            <property name="caseIndent" value="0" />
-        </module> 
-        <module name="TodoComment"/>
-        <module name="UpperEll"/>
-
-    </module>
-
-</module>
diff --git a/hadoop-project-dist/pom.xml b/hadoop-project-dist/pom.xml
index d2065938d9..c26aa9aa33 100644
--- a/hadoop-project-dist/pom.xml
+++ b/hadoop-project-dist/pom.xml
@@ -106,17 +106,6 @@
           <maxHeap>2048</maxHeap>
         </configuration>
       </plugin>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-checkstyle-plugin</artifactId>
-        <configuration>
-          <configLocation>file://${basedir}/dev-support/checkstyle.xml</configLocation>
-          <failOnViolation>false</failOnViolation>
-          <format>xml</format>
-          <format>html</format>
-          <outputFile>${project.build.directory}/test/checkstyle-errors.xml</outputFile>
-        </configuration>
-      </plugin>
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-javadoc-plugin</artifactId>
diff --git a/hadoop-project/pom.xml b/hadoop-project/pom.xml
index 9674de1b56..f23a2ddfa5 100644
--- a/hadoop-project/pom.xml
+++ b/hadoop-project/pom.xml
@@ -102,7 +102,6 @@
     <maven-jar-plugin.version>2.5</maven-jar-plugin.version>
     <maven-war-plugin.version>2.4</maven-war-plugin.version>
     <maven-source-plugin.version>2.3</maven-source-plugin.version>
-    <maven-checkstyle-plugin.version>2.12.1</maven-checkstyle-plugin.version>
     <maven-project-info-reports-plugin.version>2.7</maven-project-info-reports-plugin.version>
     <maven-pdf-plugin.version>1.2</maven-pdf-plugin.version>
     <build-helper-maven-plugin.version>1.9</build-helper-maven-plugin.version>
@@ -1023,11 +1022,6 @@
           <artifactId>findbugs-maven-plugin</artifactId>
           <version>${findbugs.version}</version>
         </plugin>
-        <plugin>
-          <groupId>org.apache.maven.plugins</groupId>
-          <artifactId>maven-checkstyle-plugin</artifactId>
-          <version>${maven-checkstyle-plugin.version}</version>
-        </plugin>
         <plugin>
           <groupId>org.codehaus.mojo</groupId>
           <artifactId>native-maven-plugin</artifactId>
diff --git a/hadoop-tools/hadoop-azure/src/config/checkstyle.xml b/hadoop-tools/hadoop-azure/src/config/checkstyle.xml
index f68f6c8208..acf6f7f7ef 100644
--- a/hadoop-tools/hadoop-azure/src/config/checkstyle.xml
+++ b/hadoop-tools/hadoop-azure/src/config/checkstyle.xml
@@ -157,7 +157,6 @@
             <property name="ignoreNumbers" value="-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 255, 1000, 1024"/>
         </module>
         <module name="MissingSwitchDefault"/>
-        <module name="RedundantThrows"/>
         <module name="SimplifyBooleanExpression"/>
         <module name="SimplifyBooleanReturn"/>
 
diff --git a/hadoop-tools/hadoop-distcp/pom.xml b/hadoop-tools/hadoop-distcp/pom.xml
index 2dace6a533..374155d47c 100644
--- a/hadoop-tools/hadoop-distcp/pom.xml
+++ b/hadoop-tools/hadoop-distcp/pom.xml
@@ -160,13 +160,6 @@
           </execution>
         </executions>
       </plugin>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-checkstyle-plugin</artifactId>
-        <configuration>
-          <enableRulesSummary>true</enableRulesSummary>
-        </configuration>
-      </plugin>
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-jar-plugin</artifactId>
diff --git a/pom.xml b/pom.xml
index 3bad969ee8..1ea52eb681 100644
--- a/pom.xml
+++ b/pom.xml
@@ -103,6 +103,8 @@ xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xs
     <maven-clover2-plugin.version>3.3.0</maven-clover2-plugin.version>
     <maven-bundle-plugin.version>2.5.0</maven-bundle-plugin.version>
     <lifecycle-mapping.version>1.0.0</lifecycle-mapping.version>
+    <maven-checkstyle-plugin.version>2.15</maven-checkstyle-plugin.version>
+    <checkstyle.version>6.6</checkstyle.version>
   </properties>
 
   <modules>
@@ -118,6 +120,7 @@ xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xs
     <module>hadoop-dist</module>
     <module>hadoop-client</module>
     <module>hadoop-minicluster</module>
+    <module>hadoop-build-tools</module>
   </modules>
 
   <build>
@@ -292,6 +295,30 @@ xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xs
           <artifactId>maven-bundle-plugin</artifactId>
           <version>${maven-bundle-plugin.version}</version>
         </plugin>
+        <plugin>
+          <groupId>org.apache.maven.plugins</groupId>
+          <artifactId>maven-checkstyle-plugin</artifactId>
+          <version>${maven-checkstyle-plugin.version}</version>
+          <dependencies>
+            <dependency>
+              <groupId>org.apache.hadoop</groupId>
+              <artifactId>hadoop-build-tools</artifactId>
+              <version>${project.version}</version>
+            </dependency>
+            <dependency>
+              <groupId>com.puppycrawl.tools</groupId>
+              <artifactId>checkstyle</artifactId>
+              <version>${checkstyle.version}</version>
+            </dependency>
+          </dependencies>
+          <configuration>
+            <configLocation>checkstyle/checkstyle.xml</configLocation>
+            <failOnViolation>false</failOnViolation>
+            <format>xml</format>
+            <format>html</format>
+            <outputFile>${project.build.directory}/test/checkstyle-errors.xml</outputFile>
+          </configuration>
+        </plugin>
       </plugins>
     </pluginManagement>
 
@@ -357,6 +384,11 @@ xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xs
         <inherited>true</inherited>
         <extensions>true</extensions>
       </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-checkstyle-plugin</artifactId>
+        <version>${maven-checkstyle-plugin.version}</version>
+      </plugin>
     </plugins>
   </build>