checkstyle.xml

<?xml version="1.0"?>
<!DOCTYPE module PUBLIC
				"-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
				"https://checkstyle.org/dtds/configuration_1_3.dtd">

<!--
    Checkstyle configuration that checks the Google coding conventions from Google Java Style
    that can be found at https://google.github.io/styleguide/javaguide.html

    Checkstyle is very configurable. Be sure to read the documentation at
    http://checkstyle.org (or in your downloaded distribution).

    To completely disable a check, just comment it out or delete it from the file.
    To suppress certain violations please review suppression filters.

    Authors: Max Vetrenko, Ruslan Diachenko, Roman Ivanov.
 -->

<module name = "Checker">
	<property name="charset" value="UTF-8"/>

	<property name="severity" value="warning"/>

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

	<!-- Checks for whitespace                               -->
	<!-- See http://checkstyle.org/config_whitespace.html -->
	<module name="FileTabCharacter">
		<property name="eachLine" value="true"/>
	</module>

	<module name="LineLength">
		<property name="fileExtensions" value="java"/>
		<property name="max" value="100"/>
		<property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
	</module>

	<module name="TreeWalker">
		<module name="OuterTypeFilename"/>
		<module name="IllegalTokenText">
			<property name="tokens" value="STRING_LITERAL, CHAR_LITERAL"/>
			<property name="format" value="\\u00(09|0(a|A)|0(c|C)|0(d|D)|22|27|5(C|c))|\\(0(10|11|12|14|15|42|47)|134)"/>
			<property name="message" value="Consider using special escape sequence instead of octal value or Unicode escaped value."/>
		</module>
		<module name="AvoidEscapedUnicodeCharacters">
			<property name="allowEscapesForControlCharacters" value="true"/>
			<property name="allowByTailComment" value="true"/>
			<property name="allowNonPrintableEscapes" value="true"/>
		</module>
		<module name="AvoidStarImport"/>
		<module name="OneTopLevelClass"/>
		<module name="NoLineWrap">
			<property name="tokens" value="PACKAGE_DEF, IMPORT, STATIC_IMPORT"/>
		</module>
		<module name="EmptyBlock">
			<property name="option" value="TEXT"/>
			<property name="tokens" value="LITERAL_TRY, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_SWITCH"/>
		</module>
		<module name="NeedBraces">
			<property name="tokens" value="LITERAL_DO, LITERAL_ELSE, LITERAL_FOR, LITERAL_IF, LITERAL_WHILE"/>
		</module>
		<module name="LeftCurly">
			<property name="tokens" value="ANNOTATION_DEF, CLASS_DEF, CTOR_DEF, ENUM_CONSTANT_DEF, ENUM_DEF,
                    INTERFACE_DEF, LAMBDA, LITERAL_CASE, LITERAL_CATCH, LITERAL_DEFAULT,
                    LITERAL_DO, LITERAL_ELSE, LITERAL_FINALLY, LITERAL_FOR, LITERAL_IF,
                    LITERAL_SWITCH, LITERAL_SYNCHRONIZED, LITERAL_TRY, LITERAL_WHILE, METHOD_DEF,
                    OBJBLOCK, STATIC_INIT"/>
		</module>
		<module name="RightCurly">
			<property name="id" value="RightCurlySame"/>
			<property name="tokens" value="LITERAL_TRY, LITERAL_CATCH, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE,
                    LITERAL_DO"/>
		</module>
		<module name="RightCurly">
			<property name="id" value="RightCurlyAlone"/>
			<property name="option" value="alone"/>
			<property name="tokens" value="CLASS_DEF, METHOD_DEF, CTOR_DEF, LITERAL_FOR, LITERAL_WHILE, STATIC_INIT,
                    INSTANCE_INIT, ANNOTATION_DEF, ENUM_DEF"/>
		</module>
		<module name="SuppressionXpathSingleFilter">
			<!-- suppresion is required till https://github.com/checkstyle/checkstyle/issues/7541 -->
			<property name="id" value="RightCurlyAlone"/>
			<property name="query" value="//RCURLY[parent::SLIST[count(./*)=1]
                                                 or preceding-sibling::*[last()][self::LCURLY]]"/>
		</module>
		<module name="WhitespaceAround">
			<property name="allowEmptyConstructors" value="true"/>
			<property name="allowEmptyLambdas" value="true"/>
			<property name="allowEmptyMethods" value="true"/>
			<property name="allowEmptyTypes" value="true"/>
			<property name="allowEmptyLoops" value="true"/>
			<property name="tokens" value="ASSIGN, BAND, BAND_ASSIGN, BOR, BOR_ASSIGN, BSR, BSR_ASSIGN, BXOR,
                    BXOR_ASSIGN, COLON, DIV, DIV_ASSIGN, DO_WHILE, EQUAL, GE, GT, LAMBDA, LAND,
                    LCURLY, LE, LITERAL_CATCH, LITERAL_DO, LITERAL_ELSE, LITERAL_FINALLY,
                    LITERAL_FOR, LITERAL_IF, LITERAL_RETURN, LITERAL_SWITCH, LITERAL_SYNCHRONIZED,
                     LITERAL_TRY, LITERAL_WHILE, LOR, LT, MINUS, MINUS_ASSIGN, MOD, MOD_ASSIGN,
                     NOT_EQUAL, PLUS, PLUS_ASSIGN, QUESTION, RCURLY, SL, SLIST, SL_ASSIGN, SR,
                     SR_ASSIGN, STAR, STAR_ASSIGN, LITERAL_ASSERT, TYPE_EXTENSION_AND"/>
			<message key="ws.notFollowed" value="WhitespaceAround: ''{0}'' is not followed by whitespace. Empty blocks may only be represented as '{}' when not part of a multi-block statement (4.1.3)"/>
			<message key="ws.notPreceded" value="WhitespaceAround: ''{0}'' is not preceded with whitespace."/>
		</module>
		<module name="OneStatementPerLine"/>
		<module name="MultipleVariableDeclarations"/>
		<module name="ArrayTypeStyle"/>
		<module name="MissingSwitchDefault"/>
		<module name="FallThrough"/>
		<module name="UpperEll"/>
		<module name="ModifierOrder"/>
		<module name="EmptyLineSeparator">
			<property name="tokens" value="PACKAGE_DEF, IMPORT, STATIC_IMPORT, CLASS_DEF, INTERFACE_DEF, ENUM_DEF,
                    STATIC_INIT, INSTANCE_INIT, METHOD_DEF, CTOR_DEF, VARIABLE_DEF"/>
			<property name="allowNoEmptyLineBetweenFields" value="true"/>
		</module>
		<module name="SeparatorWrap">
			<property name="id" value="SeparatorWrapDot"/>
			<property name="tokens" value="DOT"/>
			<property name="option" value="nl"/>
		</module>
		<module name="SeparatorWrap">
			<property name="id" value="SeparatorWrapComma"/>
			<property name="tokens" value="COMMA"/>
			<property name="option" value="EOL"/>
		</module>
		<module name="SeparatorWrap">
			<!-- ELLIPSIS is EOL until https://github.com/google/styleguide/issues/258 -->
			<property name="id" value="SeparatorWrapEllipsis"/>
			<property name="tokens" value="ELLIPSIS"/>
			<property name="option" value="EOL"/>
		</module>
		<module name="SeparatorWrap">
			<!-- ARRAY_DECLARATOR is EOL until https://github.com/google/styleguide/issues/259 -->
			<property name="id" value="SeparatorWrapArrayDeclarator"/>
			<property name="tokens" value="ARRAY_DECLARATOR"/>
			<property name="option" value="EOL"/>
		</module>
		<module name="SeparatorWrap">
			<property name="id" value="SeparatorWrapMethodRef"/>
			<property name="tokens" value="METHOD_REF"/>
			<property name="option" value="nl"/>
		</module>
		<module name="PackageName">
			<property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$"/>
			<message key="name.invalidPattern" value="Package name ''{0}'' must match pattern ''{1}''."/>
		</module>
		<module name="TypeName">
			<property name="tokens" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, ANNOTATION_DEF"/>
			<message key="name.invalidPattern" value="Type name ''{0}'' must match pattern ''{1}''."/>
		</module>
		<module name="MemberName">
			<property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9]*$"/>
			<message key="name.invalidPattern" value="Member name ''{0}'' must match pattern ''{1}''."/>
		</module>
		<module name="ParameterName">
			<property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
			<message key="name.invalidPattern" value="Parameter name ''{0}'' must match pattern ''{1}''."/>
		</module>
		<module name="LambdaParameterName">
			<property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
			<message key="name.invalidPattern" value="Lambda parameter name ''{0}'' must match pattern ''{1}''."/>
		</module>
		<module name="CatchParameterName">
			<property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
			<message key="name.invalidPattern" value="Catch parameter name ''{0}'' must match pattern ''{1}''."/>
		</module>
		<module name="LocalVariableName">
			<property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
			<message key="name.invalidPattern" value="Local variable name ''{0}'' must match pattern ''{1}''."/>
		</module>
		<module name="ClassTypeParameterName">
			<property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
			<message key="name.invalidPattern" value="Class type name ''{0}'' must match pattern ''{1}''."/>
		</module>
		<module name="MethodTypeParameterName">
			<property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
			<message key="name.invalidPattern" value="Method type name ''{0}'' must match pattern ''{1}''."/>
		</module>
		<module name="InterfaceTypeParameterName">
			<property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
			<message key="name.invalidPattern" value="Interface type name ''{0}'' must match pattern ''{1}''."/>
		</module>
		<module name="NoFinalizer"/>
		<module name="GenericWhitespace">
			<message key="ws.followed" value="GenericWhitespace ''{0}'' is followed by whitespace."/>
			<message key="ws.preceded" value="GenericWhitespace ''{0}'' is preceded with whitespace."/>
			<message key="ws.illegalFollow" value="GenericWhitespace ''{0}'' should followed by whitespace."/>
			<message key="ws.notPreceded" value="GenericWhitespace ''{0}'' is not preceded with whitespace."/>
		</module>
		<module name="Indentation">
			<property name="basicOffset" value="2"/>
			<property name="braceAdjustment" value="0"/>
			<property name="caseIndent" value="2"/>
			<property name="throwsIndent" value="4"/>
			<property name="lineWrappingIndentation" value="4"/>
			<property name="arrayInitIndent" value="2"/>
		</module>
		<module name="AbbreviationAsWordInName">
			<property name="ignoreFinal" value="false"/>
			<property name="allowedAbbreviationLength" value="1"/>
			<property name="tokens" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, ANNOTATION_DEF, ANNOTATION_FIELD_DEF,
                    PARAMETER_DEF, VARIABLE_DEF, METHOD_DEF"/>
		</module>
		<module name="OverloadMethodsDeclarationOrder"/>
		<module name="VariableDeclarationUsageDistance"/>
		<module name="CustomImportOrder">
			<property name="sortImportsInGroupAlphabetically" value="true"/>
			<property name="separateLineBetweenGroups" value="true"/>
			<property name="tokens" value="IMPORT, STATIC_IMPORT, PACKAGE_DEF"/>
		</module>
		<module name="MethodParamPad">
			<property name="tokens" value="CTOR_DEF, LITERAL_NEW, METHOD_CALL, METHOD_DEF,
                    SUPER_CTOR_CALL, ENUM_CONSTANT_DEF"/>
		</module>
		<module name="NoWhitespaceBefore">
			<property name="tokens" value="COMMA, SEMI, POST_INC, POST_DEC, DOT, ELLIPSIS, METHOD_REF"/>
			<property name="allowLineBreaks" value="true"/>
		</module>
		<module name="ParenPad">
			<property name="tokens" value="ANNOTATION, ANNOTATION_FIELD_DEF, CTOR_CALL, CTOR_DEF, DOT, ENUM_CONSTANT_DEF,
                    EXPR, LITERAL_CATCH, LITERAL_DO, LITERAL_FOR, LITERAL_IF, LITERAL_NEW,
                    LITERAL_SWITCH, LITERAL_SYNCHRONIZED, LITERAL_WHILE, METHOD_CALL,
                    METHOD_DEF, QUESTION, RESOURCE_SPECIFICATION, SUPER_CTOR_CALL, LAMBDA"/>
		</module>
		<module name="OperatorWrap">
			<property name="option" value="NL"/>
			<property name="tokens" value="BAND, BOR, BSR, BXOR, DIV, EQUAL, GE, GT, LAND, LE, LITERAL_INSTANCEOF, LOR,
                    LT, MINUS, MOD, NOT_EQUAL, PLUS, QUESTION, SL, SR, STAR, METHOD_REF "/>
		</module>
		<module name="AnnotationLocation">
			<property name="id" value="AnnotationLocationMostCases"/>
			<property name="tokens" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF"/>
		</module>
		<module name="AnnotationLocation">
			<property name="id" value="AnnotationLocationVariables"/>
			<property name="tokens" value="VARIABLE_DEF"/>
			<property name="allowSamelineMultipleAnnotations" value="true"/>
		</module>
		<module name="NonEmptyAtclauseDescription"/>
		<module name="InvalidJavadocPosition"/>
		<module name="JavadocTagContinuationIndentation"/>
		<module name="SummaryJavadoc">
			<property name="forbiddenSummaryFragments" value="^@return the *|^This method returns |^A [{]@code [a-zA-Z0-9]+[}]( is a )"/>
		</module>
		<module name="JavadocParagraph"/>
		<module name="AtclauseOrder">
			<property name="tagOrder" value="@param, @return, @throws, @deprecated"/>
			<property name="target" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF, VARIABLE_DEF"/>
		</module>
		<module name="JavadocMethod">
			<property name="scope" value="public"/>
			<property name="allowMissingParamTags" value="true"/>
			<property name="allowMissingReturnTag" value="true"/>
			<property name="allowedAnnotations" value="Override, Test"/>
			<property name="tokens" value="METHOD_DEF, CTOR_DEF, ANNOTATION_FIELD_DEF"/>
		</module>
		<module name="MissingJavadocMethod">
			<property name="scope" value="public"/>
			<property name="minLineCount" value="2"/>
			<property name="allowedAnnotations" value="Override, Test"/>
			<property name="tokens" value="METHOD_DEF, CTOR_DEF, ANNOTATION_FIELD_DEF"/>
		</module>
		<module name="MethodName">
			<property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9_]*$"/>
			<message key="name.invalidPattern" value="Method name ''{0}'' must match pattern ''{1}''."/>
		</module>
		<module name="SingleLineJavadoc">
			<property name="ignoreInlineTags" value="false"/>
		</module>
		<module name="EmptyCatchBlock">
			<property name="exceptionVariableName" value="expected"/>
		</module>
		<module name="CommentsIndentation">
			<property name="tokens" value="SINGLE_LINE_COMMENT, BLOCK_COMMENT_BEGIN"/>
		</module>
	</module>
</module>