checkstyle.xml

<?xml version="1.0"?>
<!--
   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

   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.
-->
<!DOCTYPE module PUBLIC
      "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
      "https://checkstyle.org/dtds/configuration_1_3.dtd">

  <!--
    Checkstyle checks configured for Maven.
  -->

  <module name="Checker">

      <!--
          If you set the basedir property below, then all reported file
          names will be relative to the specified directory. See
          https://checkstyle.org/config.html#Checker

          <property name="basedir" value="${basedir}"/>
      -->
      <property name="severity" value="error"/>

      <property name="fileExtensions" value="java, properties, xml"/>

      <!-- Excludes all 'module-info.java' files                            -->
      <!-- See https://checkstyle.org/filefilters/index.html                -->
      <module name="BeforeExecutionExclusionFileFilter">
          <property name="fileNamePattern" value="module\-info\.java$"/>
      </module>

      <!-- https://checkstyle.org/filters/suppressionfilter.html           -->
      <module name="SuppressionFilter">
          <property name="file" value="${org.checkstyle.sun.suppressionfilter.config}"
                    default="checkstyle-suppressions.xml" />
          <property name="optional" value="true"/>
      </module>

      <!-- Checks that a package-info.java file exists for each package.    -->
      <!-- See https://checkstyle.org/checks/javadoc/javadocpackage.html    -->
      <module name="JavadocPackage"/>

      <!-- Checks whether files end with a new line.                        -->
      <!-- See https://checkstyle.org/checks/misc/newlineatendoffile.html   -->
      <!-- module name="NewlineAtEndOfFile"/-->

      <!-- Checks that property files contain the same keys.                -->
      <!-- See https://checkstyle.org/checks/misc/translation.html          -->
      <module name="Translation"/>

      <!-- Checks for Size Violations.                                      -->
      <!-- See https://checkstyle.org/checks/sizes/index.html               -->
      <module name="FileLength"/>
      <module name="LineLength">
          <property name="fileExtensions" value="java"/>
          <property name="max" value="132"/>
      </module>

      <!-- Checks for whitespace                                            -->
      <!-- See https://checkstyle.org/checks/whitespace/index.html          -->
      <module name="FileTabCharacter"/>

      <!-- Miscellaneous other checks.                                      -->
      <!-- See https://checkstyle.org/checks/misc/index.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>

      <!-- Checks for Headers                                               -->
      <!-- See https://checkstyle.org/checks/header/index.html              -->
      <module name="Header">
          <property name="headerFile" value="${checkstyle.header.file}"/>
          <property name="fileExtensions" value="java, xml"/>
      </module>

      <module name="TreeWalker">

          <!-- Checks for Javadoc comments.                                 -->
          <!-- See https://checkstyle.org/checks/javadoc/index.html         -->
          <module name="InvalidJavadocPosition"/>
          <module name="JavadocMethod"/>
          <module name="JavadocType"/>
          <module name="JavadocVariable">
              <property name="scope" value="protected"/>
          </module>
          <module name="JavadocStyle"/>
          <module name="MissingJavadocMethod"/>

          <!-- Checks for Naming Conventions.                               -->
          <!-- See https://checkstyle.org/checks/naming/index.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 https://checkstyle.org/checks/imports/index.html         -->
          <module name="AvoidStarImport"/>
          <module name="IllegalImport"/> <!-- defaults to sun.* packages -->
          <module name="RedundantImport"/>
          <module name="UnusedImports"/>

          <!-- Checks for Size Violations.                                  -->
          <!-- See https://checkstyle.org/checks/sizes/index.html           -->
          <module name="MethodLength"/>
          <module name="ParameterNumber"/>

          <!-- Checks for whitespace                                        -->
          <!-- See https://checkstyle.org/checks/whitespace/index.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 https://checkstyle.org/checks/modifier/index.html        -->
          <module name="ModifierOrder"/>
          <module name="RedundantModifier"/>

          <!-- Checks for blocks. You know, those {}'s                      -->
          <!-- See https://checkstyle.org/checks/blocks/index.html          -->
          <module name="AvoidNestedBlocks"/>
          <module name="EmptyBlock"/>
          <module name="LeftCurly"/>
          <module name="NeedBraces"/>
          <module name="RightCurly"/>

          <!-- Checks for common coding problems                            -->
          <!-- See https://checkstyle.org/checks/coding/index.html          -->
          <module name="EmptyStatement"/>
          <module name="EqualsHashCode"/>
          <!-- module name="HiddenField"/ -->
          <module name="IllegalInstantiation"/>
          <module name="InnerAssignment"/>
          <module name="MagicNumber"/>
          <module name="MissingSwitchDefault"/>
          <module name="MultipleVariableDeclarations"/>
          <module name="SimplifyBooleanExpression"/>
          <module name="SimplifyBooleanReturn"/>

          <!-- Checks for class design                                      -->
          <!-- See https://checkstyle.org/checks/design/index.html          -->
          <module name="DesignForExtension"/>
          <module name="FinalClass"/>
          <module name="HideUtilityClassConstructor"/>
          <module name="InterfaceIsType"/>
          <module name="VisibilityModifier"/>

          <!-- Miscellaneous other checks.                                  -->
          <!-- See https://checkstyle.org/checks/misc/index.html            -->
          <module name="ArrayTypeStyle"/>
          <!-- module name="FinalParameters"/ -->
          <module name="TodoComment"/>
          <module name="UpperEll"/>

          <!-- https://checkstyle.org/filters/suppressionxpathfilter.html   -->
          <module name="SuppressionXpathFilter">
              <property name="file" value="${org.checkstyle.sun.suppressionxpathfilter.config}"
                        default="checkstyle-xpath-suppressions.xml" />
              <property name="optional" value="true"/>
          </module>

      </module>

  </module>