checkstyle.xml

<!DOCTYPE module PUBLIC
        "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
        "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">

<!--
    Checkstyle configuration based on the Google coding conventions from:
    -  Google Java Style
       https://google.github.io/styleguide/javaguide.html
-->

<module name="Checker">

    <module name="NewlineAtEndOfFile"/>
    <module name="FileLength">
        <property name="max" value="10000"/>
    </module>
    <module name="FileTabCharacter"/>

    <!-- Trailing spaces -->
    <module name="RegexpSingleline">
        <property name="format" value="\s+$"/>
        <property name="message" value="Line has trailing spaces."/>
    </module>

    <!-- Space after 'for' and 'if' -->
    <module name="RegexpSingleline">
        <property name="format" value="^\s*(for|if)\b[^ ]"/>
        <property name="message" value="Space needed before opening parenthesis."/>
    </module>

    <!-- For each spacing -->
    <module name="RegexpSingleline">
        <property name="format" value="^\s*for \(.*?([^ ]:|:[^ ])"/>
        <property name="message" value="Space needed around ':' character."/>
    </module>

    <module name="TreeWalker">

        <!-- Checks for Javadoc comments.                     -->
        <!-- See http://checkstyle.sf.net/config_javadoc.html -->
        <module name="JavadocStyle"/>


        <!-- Checks for Naming Conventions.                  -->
        <!-- See http://checkstyle.sf.net/config_naming.html -->
        <!--<module name="ConstantName"/>-->
        <module name="LocalFinalVariableName"/>
        <module name="LocalVariableName"/>
        <module name="MemberName"/>
        <module name="MethodName"/>
        <module name="ParameterName"/>
        <module name="StaticVariableName"/>
        <module name="TypeName"/>
        <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>

        <!-- Checks for imports                              -->
        <!-- See http://checkstyle.sf.net/config_import.html -->
        <module name="AvoidStarImport"/>
        <module name="IllegalImport"/>
        <!-- defaults to sun.* packages -->
        <module name="RedundantImport"/>
        <module name="UnusedImports">
            <property name="processJavadoc" value="true"/>
        </module>


        <!-- Checks for Size Violations.                    -->
        <!-- See http://checkstyle.sf.net/config_sizes.html -->
        <module name="MethodLength">
            <property name="max" value="200"/>
        </module>


        <!-- Checks for whitespace                               -->
        <!-- See http://checkstyle.sf.net/config_whitespace.html -->
        <module name="GenericWhitespace"/>
        <module name="MethodParamPad"/>
        <module name="OperatorWrap"/>
        <module name="ParenPad"/>
        <module name="TypecastParenPad"/>
        <module name="WhitespaceAfter"/>
        <module name="WhitespaceAround">
            <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, 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, SL, SLIST,
          SL_ASSIGN, SR, SR_ASSIGN, STAR, STAR_ASSIGN, LITERAL_ASSERT, TYPE_EXTENSION_AND"/>
        </module>


        <!-- Modifier Checks                                    -->
        <!-- See http://checkstyle.sf.net/config_modifiers.html -->
        <module name="ModifierOrder"/>
        <module name="RedundantModifier"/>


        <!-- Checks for blocks. You know, those { }'s         -->
        <!-- See http://checkstyle.sf.net/config_blocks.html -->
        <module name="AvoidNestedBlocks"/>
        <module name="LeftCurly"/>
        <module name="RightCurly"/>


        <!-- Checks for common coding problems               -->
        <!-- See http://checkstyle.sf.net/config_coding.html -->
        <module name="CovariantEquals"/>
        <module name="EmptyStatement"/>
        <module name="EqualsHashCode"/>
        <module name="IllegalInstantiation"/>
        <module name="SimplifyBooleanExpression"/>
        <module name="SimplifyBooleanReturn"/>

        <!-- Checks for class design                         -->
        <!-- See http://checkstyle.sf.net/config_design.html -->
        <module name="HideUtilityClassConstructor"/>

        <!-- Miscellaneous other checks.                   -->
        <!-- See http://checkstyle.sf.net/config_misc.html -->
        <module name="ArrayTypeStyle"/>
        <module name="UpperEll"/>

        <!-- Make the @SuppressWarnings annotations available to Checkstyle -->
        <module name="SuppressWarningsHolder"/>
    </module>

    <!-- Filter out Checkstyle warnings that have been suppressed with the @SuppressWarnings annotation -->
    <module name="SuppressWarningsFilter"/>
</module>