checkstyle.xml

<?xml version="1.0" encoding="UTF-8"?>

<!--
  MIT License

  Copyright 2018 Sabre GLBL Inc.

  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:

  The above copyright notice and this permission notice shall be included in all
  copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  SOFTWARE.
  -->

<!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"/>
    <module name="NewlineAtEndOfFile">
        <property name="lineSeparator" value="lf"/>
    </module>
    <module name="UniqueProperties"/>
    <module name="FileTabCharacter">
        <property name="fileExtensions" value="java,xml,properties,txt,md,yaml"/>
    </module>
    <module name="RegexpSingleline">
        <!-- \s matches whitespace character, $ matches end of line. -->
        <property name="format" value="\s+$"/>
        <property name="message" value="Line has trailing spaces."/>
    </module>
    <module name="TreeWalker">
        <!-- Annotations -->
        <module name="AnnotationLocation">
            <property name="allowSamelineSingleParameterlessAnnotation" value="false"/>
        </module>
        <module name="AnnotationUseStyle">
            <!-- It looks there is a bug - 'always' reports issue for valid
            @SpringItemsConfigurationSource(@SpringItemConfigurationSource) -->
            <property name="closingParens" value="ignore"/>
        </module>
        <module name="MissingDeprecated"/>
        <module name="MissingOverride"/>
        <module name="PackageAnnotation"/>

        <!-- Block Checks -->
        <module name="AvoidNestedBlocks"/>
        <module name="EmptyBlock"/>
        <module name="EmptyCatchBlock">
            <property name="exceptionVariableName" value="ignore|expected"/>
        </module>
        <module name="LeftCurly"/>
        <module name="NeedBraces"/>
        <module name="RightCurly"/>

        <!-- Class Design -->
        <module name="FinalClass"/>
        <module name="HideUtilityClassConstructor"/>
        <module name="MutableException"/>
        <module name="OneTopLevelClass"/>
        <module name="ThrowsCount"/>

        <!-- Coding -->
        <module name="CovariantEquals"/>
        <module name="DefaultComesLast"/>
        <module name="EmptyStatement"/>
        <module name="EqualsHashCode"/>
        <module name="FallThrough"/>
        <module name="IllegalThrows"/>
        <module name="InnerAssignment"/>
        <module name="MissingSwitchDefault"/>
        <module name="ModifiedControlVariable"/>
        <module name="MultipleVariableDeclarations"/>
        <module name="NoFinalizer"/>
        <module name="OneStatementPerLine"/>
        <module name="PackageDeclaration"/>
        <module name="ParameterAssignment"/>
        <module name="SimplifyBooleanExpression"/>
        <module name="SimplifyBooleanReturn"/>
        <module name="StringLiteralEquality"/>

        <!-- Imports -->
        <module name="IllegalImport"/>
        <module name="RedundantImport"/>
        <module name="UnusedImports"/>

        <!-- Miscellaneous -->
        <module name="ArrayTypeStyle"/>
        <module name="CommentsIndentation"/>
        <module name="Indentation">
            <property name="arrayInitIndent" value="8"/>
            <property name="lineWrappingIndentation" value="8"/>
        </module>
        <module name="UpperEll"/>

        <!-- Modifiers -->
        <module name="ModifierOrder"/>
        <module name="RedundantModifier"/>

        <!-- Naming Conventions -->
        <module name="CatchParameterName"/>
        <module name="ClassTypeParameterName"/>
        <module name="InterfaceTypeParameterName"/>
        <module name="LocalFinalVariableName"/>
        <module name="LocalVariableName"/>
        <module name="MemberName"/>
        <module name="MethodName"/>
        <module name="MethodTypeParameterName"/>
        <module name="OuterTypeFilename"/>
        <module name="PackageName"/>
        <module name="ParameterName"/>
        <module name="StaticVariableName"/>
        <module name="TypeName"/>

        <!-- Whitespace -->
        <module name="EmptyForInitializerPad"/>
        <module name="EmptyForIteratorPad"/>
        <module name="EmptyLineSeparator">
            <property name="tokens"
                      value="PACKAGE_DEF, IMPORT, CLASS_DEF, INTERFACE_DEF, ENUM_DEF, STATIC_INIT, INSTANCE_INIT, METHOD_DEF, CTOR_DEF"/>
        </module>
        <module name="GenericWhitespace"/>
        <module name="MethodParamPad"/>
        <module name="NoWhitespaceAfter"/>
        <module name="NoWhitespaceBefore"/>
        <module name="SeparatorWrap">
            <property name="option" value="eol"/>
            <property name="tokens" value="COMMA"/>
        </module>
        <module name="SeparatorWrap">
            <property name="option" value="nl"/>
            <property name="tokens" value="DOT"/>
        </module>
        <module name="SingleSpaceSeparator"/>
        <module name="TypecastParenPad"/>
        <module name="WhitespaceAfter"/>
        <module name="WhitespaceAround"/>
    </module>
</module>