checkstyle_checks.xml

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

<module name="Checker">
  <module name="SuppressWarningsFilter"/>

  <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/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.google.suppressionfilter.config}"
           default="checkstyle-suppressions.xml" />
    <property name="optional" value="true"/>
  </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="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, RECORD_DEF, COMPACT_CTOR_DEF"/>
    </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, INTERFACE_DEF, RECORD_DEF,
                    COMPACT_CTOR_DEF, LITERAL_SWITCH"/>
    </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>
    <!-- our new checkstyle rule -->
    <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="ignoreEnhancedForColon" value="false"/>
      <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="MissingSwitchDefault"/>
    <module name="FallThrough"/>
    <module name="UpperEll"/>
    <module name="ModifierOrder"/>
    <module name="PackageName">
      <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$"/>
      <message key="name.invalidPattern"
             value="Package name ''{0}'' must match pattern ''{1}''."/>
    </module>
    <module name="TypeName">
      <property name="tokens" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF,
                    ANNOTATION_DEF, RECORD_DEF"/>
      <message key="name.invalidPattern"
             value="Type name ''{0}'' must match pattern ''{1}''."/>
    </module>
    <module name="MemberName">
      <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9]*$"/>
      <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="PatternVariableName">
      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
      <message key="name.invalidPattern"
             value="Pattern variable name ''{0}'' must match pattern ''{1}''."/>
    </module>
    <module name="ClassTypeParameterName">
      <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
      <message key="name.invalidPattern"
             value="Class type name ''{0}'' must match pattern ''{1}''."/>
    </module>
    <module name="RecordComponentName">
      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
      <message key="name.invalidPattern"
               value="Record component name ''{0}'' must match pattern ''{1}''."/>
    </module>
    <module name="RecordTypeParameterName">
      <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
      <message key="name.invalidPattern"
               value="Record 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="MethodParamPad">
      <property name="tokens"
               value="CTOR_DEF, LITERAL_NEW, METHOD_CALL, METHOD_DEF,
                    SUPER_CTOR_CALL, ENUM_CONSTANT_DEF, RECORD_DEF"/>
    </module>
    <module name="AnnotationLocation">
      <property name="id" value="AnnotationLocationMostCases"/>
      <property name="tokens"
               value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF,
                      RECORD_DEF, COMPACT_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="MethodName">
      <property name="format" value="^[a-z][a-z0-9]\w*$"/>
      <message key="name.invalidPattern"
             value="Method name ''{0}'' must match pattern ''{1}''."/>
    </module>
    <module name="EmptyCatchBlock">
      <property name="exceptionVariableName" value="expected"/>
    </module>
    <!-- https://checkstyle.org/filters/suppressionxpathfilter.html -->
    <module name="SuppressionXpathFilter">
      <property name="file" value="${org.checkstyle.google.suppressionxpathfilter.config}"
             default="checkstyle-xpath-suppressions.xml" />
      <property name="optional" value="true"/>
    </module>
    <module name="SuppressWarningsHolder" />
    <module name="SuppressionCommentFilter">
      <property name="offCommentFormat" value="CHECKSTYLE.OFF\: ([\w\|]+)" />
      <property name="onCommentFormat" value="CHECKSTYLE.ON\: ([\w\|]+)" />
      <property name="checkFormat" value="$1" />
    </module>
    <module name="SuppressWithNearbyCommentFilter">
      <property name="commentFormat" value="CHECKSTYLE.SUPPRESS\: ([\w\|]+)"/>
      <!-- $1 refers to the first match group in the regex defined in commentFormat -->
      <property name="checkFormat" value="$1"/>
      <!-- The check is suppressed in the next line of code after the comment -->
      <property name="influenceFormat" value="1"/>
    </module>
  </module>
</module>