dev/checkstyle.xml

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

<!--

    Checkstyle configuration based on the Google coding conventions from:

    -  Google Java Style
       https://google.github.io/styleguide/javaguide.html

    with Spark-specific changes from:

    https://spark.apache.org/contributing.html#code-style-guide

    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.

    Authors: Max Vetrenko, Ruslan Diachenko, Roman Ivanov.

 -->

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

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

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

    <module name="SuppressionFilter">
      <property name="file" value="dev/checkstyle-suppressions.xml"/>
    </module>

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

    <module name="RegexpSingleline">
        <!-- \s matches whitespace character, $ matches end of line. -->
        <property name="format" value="\s+$"/>
        <property name="message" value="No trailing whitespace allowed."/>
    </module>

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

    <module name="NewlineAtEndOfFile"/>

    <module name="Header">
        <property name="charset" value="UTF-8" />
        <property name="headerFile" value="dev/java-file-header" />
        <property name="fileExtensions" value="java" />
    </module>

    <module name="TreeWalker">
        <!--
        If you wish to turn off checking for a section of code, you can put a comment in the source
        before and after the section, with the following syntax:

          // checkstyle.off: XXX (such as checkstyle.off: NoFinalizer)
          ...  // stuff that breaks the styles
          // checkstyle.on: XXX (such as checkstyle.on: NoFinalizer)
        -->
        <module name="SuppressionCommentFilter">
            <property name="offCommentFormat" value="checkstyle\.off\: ([\w\|]+)"/>
            <property name="onCommentFormat" value="checkstyle\.on\: ([\w\|]+)"/>
            <property name="checkFormat" value="$1"/>
        </module>
        <module name="OuterTypeFilename"/>
        <module name="IllegalTokenText">
            <property name="tokens" value="STRING_LITERAL, CHAR_LITERAL"/>
            <property name="format" value="\\u00(08|09|0(a|A)|0(c|C)|0(d|D)|22|27|5(C|c))|\\(0(10|11|12|14|15|42|47)|134)"/>
            <property name="message" value="Avoid using corresponding octal or Unicode escape."/>
        </module>
        <module name="AvoidEscapedUnicodeCharacters">
            <property name="allowEscapesForControlCharacters" value="true"/>
            <property name="allowByTailComment" value="true"/>
            <property name="allowNonPrintableEscapes" value="true"/>
        </module>
        <module name="NoLineWrap"/>
        <module name="EmptyBlock">
            <property name="option" value="TEXT"/>
            <property name="tokens" value="LITERAL_TRY, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_SWITCH"/>
        </module>
        <module name="NeedBraces">
            <property name="allowSingleLineStatement" value="true"/>
        </module>
        <module name="OneStatementPerLine"/>
        <module name="ArrayTypeStyle"/>
        <module name="FallThrough"/>
        <module name="UpperEll"/>
        <module name="ModifierOrder"/>
        <module name="SeparatorWrap">
            <property name="tokens" value="DOT"/>
            <property name="option" value="nl"/>
        </module>
        <module name="SeparatorWrap">
            <property name="tokens" value="COMMA"/>
            <property name="option" value="EOL"/>
        </module>
        <module name="PackageName">
            <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$"/>
            <message key="name.invalidPattern"
             value="Package name ''{0}'' must match pattern ''{1}''."/>
        </module>
        <module name="ClassTypeParameterName">
            <property name="format" value="([A-Z][a-zA-Z0-9]*$)"/>
            <message key="name.invalidPattern"
             value="Class type name ''{0}'' must match pattern ''{1}''."/>
        </module>
        <module name="MethodTypeParameterName">
            <property name="format" value="([A-Z][a-zA-Z0-9]*)"/>
            <message key="name.invalidPattern"
             value="Method type name ''{0}'' must match pattern ''{1}''."/>
        </module>
        <module name="GenericWhitespace">
            <message key="ws.followed"
             value="GenericWhitespace ''{0}'' is followed by whitespace."/>
             <message key="ws.preceded"
             value="GenericWhitespace ''{0}'' is preceded with whitespace."/>
             <message key="ws.illegalFollow"
             value="GenericWhitespace ''{0}'' should followed by whitespace."/>
             <message key="ws.notPreceded"
             value="GenericWhitespace ''{0}'' is not preceded with whitespace."/>
        </module>
        <module name="MethodParamPad"/>
        <module name="AnnotationLocation">
            <property name="tokens" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF"/>
        </module>
        <module name="AnnotationLocation">
            <property name="tokens" value="VARIABLE_DEF"/>
            <property name="allowSamelineMultipleAnnotations" value="true"/>
        </module>
        <module name="MethodName">
            <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9_]*$"/>
            <message key="name.invalidPattern"
             value="Method name ''{0}'' must match pattern ''{1}''."/>
        </module>
        <module name="EmptyCatchBlock">
            <property name="exceptionVariableName" value="expected"/>
        </module>
        <module name="CommentsIndentation"/>
        <module name="UnusedImports"/>
        <module name="RedundantImport"/>
        <module name="RedundantModifier"/>
        <module name="RegexpSinglelineJava">
            <property name="format" value="throw new \w+Error\("/>
            <property name="message" value="Avoid throwing error in application code."/>
        </module>
        <module name="RegexpSinglelineJava">
            <property name="format" value="new (java\.lang\.)?(Byte|Integer|Long|Short)\("/>
            <property name="message" value="Use static factory 'valueOf' or 'parseXXX' instead of the deprecated constructors." />
        </module>
        <module name="RegexpSinglelineJava">
            <property name="format" value="@Test\(expected"/>
            <property name="message" value="Please use the `assertThrows` method to test for exceptions." />
        </module>
        <module name="IllegalImport">
            <property name="illegalPkgs" value="org.apache.log4j" />
            <property name="illegalPkgs" value="org.apache.commons.lang" />
            <property name="illegalPkgs" value="org.apache.commons.lang3.tuple" />
            <property name="illegalClasses" value="org.apache.commons.codec.binary.Base64" />
            <property name="illegalClasses" value="org.apache.commons.io.FileUtils" />
            <property name="illegalClasses" value="org.apache.commons.lang3.JavaVersion" />
            <property name="illegalClasses" value="org.apache.commons.lang3.Strings" />
            <property name="illegalClasses" value="org.apache.commons.lang3.StringUtils" />
            <property name="illegalClasses" value="org.apache.commons.lang3.SystemUtils" />
            <property name="illegalClasses" value="org.apache.hadoop.io.IOUtils" />
            <property name="illegalClasses" value="org.apache.parquet.Preconditions" />
            <property name="illegalClasses" value="com.google.common.base.Joiner" />
            <property name="illegalClasses" value="com.google.common.base.Objects" />
            <property name="illegalClasses" value="com.google.common.base.Preconditions" />
            <property name="illegalClasses" value="com.google.common.base.Strings" />
            <property name="illegalClasses" value="com.google.common.collect.ArrayListMultimap" />
            <property name="illegalClasses" value="com.google.common.collect.Multimap" />
            <property name="illegalClasses" value="com.google.common.collect.Sets" />
            <property name="illegalClasses" value="com.google.common.io.BaseEncoding" />
            <property name="illegalClasses" value="com.google.common.io.Files" />
        </module>
        <module name="RegexpSinglelineJava">
            <property name="format" value="Ints\.checkedCast"/>
            <property name="message" value="Use JavaUtils.checkedCast instead." />
        </module>
        <module name="RegexpSinglelineJava">
            <property name="format" value="Charset\.defaultCharset"/>
            <property name="message" value="Use StandardCharsets.UTF_8 instead." />
        </module>
        <module name="RegexpSinglelineJava">
            <property name="format" value="new URL\("/>
            <property name="message" value="Use URI.toURL or URL.of instead of URL constructors." />
        </module>
        <module name="RegexpSinglelineJava">
            <property name="format" value="new ToStringBuilder\("/>
            <property name="message" value="Use String concatenation instead." />
        </module>
        <module name="RegexpSinglelineJava">
            <property name="format" value="Files\.equal\("/>
            <property name="message" value="Use contentEquals of SparkFileUtils or Utils instead." />
        </module>
        <module name="RegexpSinglelineJava">
            <property name="format" value="Files\.asCharSink"/>
            <property name="message" value="Use java.nio.file.Files.writeString instead." />
        </module>
        <module name="RegexpSinglelineJava">
            <property name="format" value="ByteStreams\.copy"/>
            <property name="message" value="Use Java transferTo instead." />
        </module>
        <module name="RegexpSinglelineJava">
            <property name="format" value="ByteStreams\.skipFully"/>
            <property name="message" value="Use Java skipNBytes instead." />
        </module>
        <module name="RegexpSinglelineJava">
            <property name="format" value="Files\.asByteSource"/>
            <property name="message" value="Use Java Files.newInputStream instead." />
        </module>
        <module name="RegexpSinglelineJava">
            <property name="format" value="ByteStreams\.readFully"/>
            <property name="message" value="Use readFully of JavaUtils/SparkStreamUtils/Utils instead." />
        </module>
        <module name="RegexpSinglelineJava">
            <property name="format" value="FileUtils.writeStringToFile"/>
            <property name="message" value="Use java.nio.file.Files.writeString instead." />
        </module>
        <module name="RegexpSinglelineJava">
            <property name="format" value="FileUtils\.deleteDirectory"/>
            <property name="message" value="Use deleteRecursively of JavaUtils/SparkFileUtils/Utils instead." />
        </module>
        <module name="RegexpSinglelineJava">
            <property name="format" value="FileUtils\.forceDelete\("/>
            <property name="message" value="Use deleteRecursively of JavaUtils/SparkFileUtils/Utils instead." />
        </module>
        <module name="RegexpSinglelineJava">
            <property name="format" value="FileUtils\.forceDeleteOnExit\("/>
            <property name="message" value="Use forceDeleteOnExit of JavaUtils/SparkFileUtils/Utils instead." />
        </module>
        <module name="RegexpSinglelineJava">
            <property name="format" value="FileUtils\.deleteQuietly"/>
            <property name="message" value="Use deleteQuietly of JavaUtils/SparkFileUtils/Utils instead." />
        </module>
        <module name="RegexpSinglelineJava">
            <property name="format" value="CharStreams\.toString"/>
            <property name="message" value="Use toString of SparkStreamUtils or Utils instead." />
        </module>
        <module name="RegexpSinglelineJava">
            <property name="format" value="Preconditions\.checkNotNull"/>
            <property name="message" value="Use requireNonNull of java.util.Objects instead." />
        </module>
        <module name="RegexpSinglelineJava">
            <property name="format" value="Lists\.newArrayList"/>
            <property name="message" value="Use ArrayList constructor instead." />
        </module>
        <module name="RegexpSinglelineJava">
            <property name="format" value="ImmutableMap\.of"/>
            <property name="message" value="Use Map.of instead." />
        </module>
        <module name="RegexpSinglelineJava">
            <property name="format" value="ImmutableSet\.of"/>
            <property name="message" value="Use Set.of instead." />
        </module>
        <module name="RegexpSinglelineJava">
            <property name="format" value="Throwables\.getStackTraceAsString"/>
            <property name="message" value="Use stackTraceToString of JavaUtils/SparkFileUtils/Utils instead." />
        </module>
        <!-- support structured logging -->
        <module name="RegexpSinglelineJava">
            <property name="format" value="org\.slf4j\.(Logger|LoggerFactory)" />
            <property name="message" value="Please use org.apache.spark.internal.(SparkLogger|SparkLoggerFactory) instead." />
        </module>
    </module>
</module>