config/quality/checkstyle/checkstyle-config.xml

<?xml version="1.0"?>
<!DOCTYPE module PUBLIC
    "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
    "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">

<module name = "Checker">

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

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

    <module name="FileTabCharacter">
        <property name="eachLine" value="true"/>
    </module>

    <module name="TreeWalker">

        <!-- Imports -->

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

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

        <!-- General Code Style -->

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

        <module name="LeftCurly">
            <property name="maxLineLength" value="100"/>
        </module>

        <module name="RightCurly">
            <property name="option" value="alone"/>
            <property name="tokens" value="CLASS_DEF, METHOD_DEF, CTOR_DEF, LITERAL_FOR, LITERAL_WHILE, LITERAL_DO, STATIC_INIT, INSTANCE_INIT"/>
        </module>

        <module name="RightCurly">
            <property name="option" value="same"/>
        </module>

        <module name="NoFinalizer"/>

        <module name="ArrayTypeStyle"/>

        <module name="ModifierOrder"/>

        <module name="Indentation">
            <property name="basicOffset" value="4"/>
            <property name="braceAdjustment" value="0"/>
            <property name="caseIndent" value="4"/>
            <property name="throwsIndent" value="4"/>
            <property name="lineWrappingIndentation" value="8"/>
            <property name="arrayInitIndent" value="2"/>
        </module>

        <!-- White Space -->

        <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="WhitespaceAround">
            <property name="allowEmptyConstructors" value="true"/>
            <property name="allowEmptyMethods" value="false"/>
            <property name="allowEmptyTypes" value="false"/>
            <property name="allowEmptyLoops" value="false"/>
            <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."/>
            <property name="severity" value="error"/>
        </module>

        <module name="WhitespaceAfter">
            <property name="tokens" value="COMMA, SEMI, TYPECAST"/>
        </module>

        <module name="NoWhitespaceBefore">
            <property name="tokens" value="SEMI, DOT, POST_DEC, POST_INC"/>
            <property name="allowLineBreaks" value="true"/>
        </module>

        <module name="NoWhitespaceAfter">
            <property name="tokens" value="BNOT, DEC, DOT, INC, LNOT, UNARY_MINUS, UNARY_PLUS"/>
            <property name="allowLineBreaks" value="true"/>
        </module>

        <!-- Naming -->

        <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="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="TypeName">
            <message key="name.invalidPattern"
                     value="Type name ''{0}'' must match pattern ''{1}''."/>
        </module>

        <module name="MemberName">
            <property name="applyToPublic" value="false" />
            <property name="applyToPackage" value="false" />
            <property name="applyToProtected" value="false" />
            <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-zA-Z0-9]*$"/>
            <message key="name.invalidPattern"
                     value="Parameter name ''{0}'' must match pattern ''{1}''."/>
        </module>

        <module name="LocalVariableName">
            <property name="tokens" value="VARIABLE_DEF"/>
            <property name="format" value="^[a-z][a-zA-Z0-9]*$"/>
            <property name="allowOneCharVarInForLoop" value="true"/>
            <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>

</module>