checkstyle.xml

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

<module name="Checker">

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

    <!-- See http://checkstyle.sourceforge.net/config_javadoc.html#PackageHtml -->
    <!-- Checks that a package.html file exists for each package. -->
    <!-- <property name="fileExtensions" value="java"/> -->
    <!-- <module name="PackageHtml"> </module> -->

    <!-- See http://checkstyle.sourceforge.net/config_sizes.html -->
    <!-- Checks for long source files. -->
    <!-- <property name="max" value="2000"/> -->
    <!-- module name="FileLength"> </module -->

    <module name="TreeWalker">

        <property name="tabWidth" value="4" />

        <!-- [aab] add in order to check whitespaces -->
        <module name="EmptyForInitializerPad">
            <property name="option" value="space" />
        </module>

        <!-- [aab] end -->
        <!-- See http://checkstyle.sourceforge.net/config_javadoc.html#JavadocType -->
        <!-- Checks Javadoc comments for class and interface definitions. -->
        <!-- <property name="scope" value="private"/> -->
        <!-- <property name="excludeScope" value=""/> -->
        <!-- <property name="authorFormat" value=""/> -->
        <!-- <property name="versionFormat" value=""/> -->
        <!-- <property name="tokens" value="INTERFACE_DEF, CLASS_DEF"/> -->
        <module name="JavadocType">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_javadoc.html#JavadocMethod -->
        <!-- Checks to ensure that the javadoc tags exist (if required) -->
        <!-- <property name="scope" value="private"/> -->
        <!-- <property name="excludeScope" value=""/> -->
        <!-- <property name="allowUndeclaredRTE" value="false"/> -->
        <!-- <property name="allowThrowsTagsForSubclasses" value="false"/> -->
        <!-- <property name="allowMissingParamTags" value="false"/> -->
        <!-- <property name="allowMissingThrowsTags" value="false"/> -->
        <!-- <property name="allowMissingReturnTag" value="false"/> -->
        <!-- <property name="tokens" value="METHOD_DEF, CTOR_DEF"/> -->
        <module name="JavadocMethod">
            <property name="scope" value="protected" />
            <property name="allowMissingParamTags" value="true" />
            <property name="allowMissingThrowsTags" value="true" />
            <property name="allowMissingReturnTag" value="true" />
            <property name="allowMissingPropertyJavadoc" value="true" />
            <property name="tokens" value="METHOD_DEF" />
            <property name="allowUndeclaredRTE" value="true" />
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_javadoc.html#JavadocVariable -->
        <!-- Checks that variables have Javadoc comments. -->
        <!-- <property name="scope" value="private"/> -->
        <!-- <property name="excludeScope" value=""/> -->
        <!--<module name="JavadocVariable"> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_javadoc.html#JavadocStyle -->
        <!-- Validates Javadoc comments to help ensure they are well formed. -->
        <!-- <property name="scope" value="private"/> -->
        <!-- <property name="excludeScope" value=""/> -->
        <!-- <property name="checkFirstSentence" value="true"/> -->
        <!-- <property name="checkEmptyJavadoc" value="false"/> -->
        <!-- <property name="checkHtml" value="true"/> -->
        <!-- <property name="tokens" value="INTERFACE_DEF, CLASS_DEF, METHOD_DEF, CTOR_DEF, VARIABLE_DEF"/> -->
        <module name="JavadocStyle">
            <property name="checkFirstSentence" value="false" />
            <property name="checkHtml" value="false" />
            <property name="checkEmptyJavadoc" value="true" />
            <property name="tokens" value="INTERFACE_DEF, CLASS_DEF" />
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_naming.html -->
        <!-- Checks for Naming Conventions. -->
        <!-- <property name="format" value="^Abstract.*$|^.*Factory$"/> -->
        <module name="AbstractClassName">
            <property name="format" value="^A[a-zA-Z0-9]*$" />
            <property name="ignoreModifier" value="true" />
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_naming.html -->
        <!-- Checks for Naming Conventions. -->
        <!-- <property name="format" value="^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$"/> -->
        <module name="ConstantName">
            <property name="format" value="instance|all|log|(^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$)" />
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_naming.html -->
        <!-- Checks for Naming Conventions. -->
        <!-- <property name="format" value="^[a-z][a-zA-Z0-9]*$"/> -->
        <!-- <property name="tokens" value="VARIABLE_DEF, PARAMETER_DEF"/> -->
        <module name="LocalFinalVariableName">
            <property name="format" value="^[a-z][a-zA-Z0-9_]*$" />
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_naming.html -->
        <!-- Checks for Naming Conventions. -->
        <!-- <property name="format" value="^[a-z][a-zA-Z0-9]*$"/> -->
        <module name="LocalVariableName">
            <property name="format" value="^[a-z][a-zA-Z0-9_]*$" />
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_naming.html -->
        <!-- Checks for Naming Conventions. -->
        <module name="MemberName">
            <property name="format" value="^[a-z][a-zA-Z0-9_]*$" />
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_naming.html -->
        <!-- Checks for Naming Conventions. -->
        <!-- <property name="format" value="^[a-z][a-zA-Z0-9]*$"/> -->
        <module name="MethodName">
            <property name="format" value="^[a-z][a-zA-Z0-9_]*$" />
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_naming.html -->
        <!-- Checks for Naming Conventions. -->

        <!-- <property name="format" value="^[a-z]+(\.[a-zA-Z_][a-zA-Z0-9_]*)*$"/> -->
        <module name="PackageName">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_naming.html -->
        <!-- Checks for Naming Conventions. -->
        <!-- <property name="format" value="^[a-z][a-zA-Z0-9]*$"/> -->
        <module name="ParameterName">
            <property name="format" value="^[a-z][a-zA-Z0-9_]*$" />
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_naming.html -->
        <!-- Checks for Naming Conventions. -->
        <!-- <property name="format" value="^[a-z][a-zA-Z0-9]*$"/> -->
        <module name="StaticVariableName">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_naming.html -->
        <!-- Checks for Naming Conventions. -->
        <!-- <property name="format" value="^[a-z][a-zA-Z0-9]*$"/> -->
        <!-- <property name="tokens" value="CLASS_DEF, INTERFACE_DEF"/> -->
        <!-- <property name="applyToPublic" value="true"/> -->
        <!-- <property name="applyToProtected" value="true"/> -->
        <!-- <property name="applyToPackage" value="true"/> -->
        <!-- <property name="applyToPrivate" value="true"/> -->
        <module name="TypeName">
            <property name="format" value="^[A-Z][a-zA-Z0-9]*(_[A-Z][a-zA-Z0-9]*)*$" />
            <property name="tokens" value="CLASS_DEF, INTERFACE_DEF" />
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_header.html -->
        <!-- Checks that a source file begins with a specified header. -->
        <!-- <property name="headerFile" value=""/> -->
        <!-- <property name="ignoreLines" value=""/> -->
        <!-- <module name="Header"> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_header.html -->
        <!-- Checks the header of a source file against a header file that contains a regular expression for each line of the source header. -->
        <!-- <property name="headerFile" value=""/> -->
        <!-- <property name="multiLines" value=""/> -->
        <!-- <module name="RegexpHeader"> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_imports.html -->
        <!-- Checks that there are no import statements that use the * notation. -->
        <!-- <property name="excludes" value=""/> -->
        <module name="AvoidStarImport">
            <property name="allowStaticMemberImports" value="true" />
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_imports.html -->
        <!-- Checks for imports from a set of illegal packages. -->
        <!-- <property name="illegalPkgs" value="sun"/> -->
        <module name="IllegalImport">
            <property name="illegalPkgs" value="sun, com.sun, com.oracle" />
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_imports.html -->
        <!-- Checks for redundant import statements. -->
        <module name="RedundantImport">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_imports.html -->
        <!-- Checks for unused import statements. -->
        <!-- <module name="UnusedImports"> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_imports.html -->
        <!-- Checks the ordering/grouping of imports. -->
        <!-- <property name="groups" value=""/> -->
        <!-- <property name="ordered" value="true"/> -->
        <!-- <property name="separated" value="false"/> -->
        <!-- <property name="caseSensitive" value="true"/> -->
        <!--<module name="ImportOrder"> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_sizes.html -->
        <!-- Restricts the number of executable statements to a specified limit. -->
        <!-- <property name="max" value="30"/> -->
        <!-- <property name="tokens" value="CTOR_DEF, METHOD_DEF, INSTANCE_INIT, STATIC_INIT"/> -->
        <!--<module name="ExecutableStatementCount"> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_sizes.html -->
        <!-- Checks for long lines. -->
        <!-- <property name="ignorePattern" value="^$"/> -->
        <!-- <property name="max" value="80"/> -->
        <module name="LineLength">
            <property name="max" value="200" />
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_sizes.html -->
        <!-- Checks for long methods and constructors. -->
        <!-- <property name="max" value="150"/> -->
        <!-- <property name="countEmpty" value="true"/> -->
        <!-- <property name="tokens" value="METHOD_DEF, CTOR_DEF"/> -->
        <module name="MethodLength">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_sizes.html -->
        <!-- Checks for long anonymous inner classes. -->
        <!-- <property name="max" value="20"/> -->
        <module name="AnonInnerLength">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_sizes.html -->
        <!-- Checks the number of parameters of a method or constructor. -->
        <!-- <property name="max" value="7"/> -->
        <!-- <property name="tokens" value="METHOD_DEF, CTOR_DEF"/> -->
        <module name="ParameterNumber">
            <property name="max" value="10" />
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_whitespace.html -->
        <!-- Checks the padding of an empty for initializer. -->
        <!-- <property name="option" value="nospace"/> -->
        <!-- <module name="EmptyForInitializerPad"> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_whitespace.html -->
        <!-- Checks the padding of an empty for iterator. -->
        <!-- <property name="option" value="nospace"/> -->
        <module name="EmptyForIteratorPad">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_whitespace.html -->
        <!-- Checks the padding between the identifier of a method definition, constructor definition, method call, or constructor invocation; and the left parenthesis of the parameter list. -->
        <!-- <property name="allowLineBreaks" value="true"/> -->
        <!-- <property name="tokens" value="CTOR_DEF, LITERAL_NEW, METHOD_CALL, METHOD_DEF, SUPER_CTOR_CALL "/> -->
        <module name="MethodParamPad">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_whitespace.html -->
        <!-- Checks that there is no whitespace after a token. -->
        <!-- <property name="allowLineBreaks" value="true"/> -->
        <!-- <property name="tokens" value="ARRAY_INIT, BNOT, DEC, DOT, INC, LNOT, UNARY_MINUS, UNARY_PLUS"/> -->
        <module name="NoWhitespaceAfter">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_whitespace.html -->
        <!-- Checks that there is no whitespace before a token. -->
        <!-- <property name="allowLineBreaks" value="false"/> -->
        <!-- <property name="tokens" value="SEMI, DOT, POST_DEC, POST_INC"/> -->
        <module name="NoWhitespaceBefore">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_whitespace.html -->
        <!-- Checks the policy on how to wrap lines on operators. -->
        <!-- <property name="option" value="nl"/> -->
        <!-- <property name="tokens" value="ASSIGN, BAND, BAND_ASSIGN, BOR, BOR_ASSIGN, BSR, BSR_ASSIGN, BXOR, BXOR_ASSIGN, COLON, DIV, DIV_ASSIGN, EQUAL, GE, GT, LAND, LE, LITERAL_INSTANCEOF, LOR, LT, 
            MINUS, MINUS_ASSIGN, MOD, MOD_ASSIGN, NOT_EQUAL, PLUS, PLUS_ASSIGN, QUESTION, SL, SL_ASSIGN, SR, SR_ASSIGN, STAR, STAR_ASSIGN"/> -->
        <module name="OperatorWrap">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_whitespace.html -->
        <!-- Checks the policy on the padding of parentheses. -->
        <!-- <property name="option" value="nospace"/> -->
        <!-- <property name="tokens" value="CTOR_CALL, LPAREN, METHOD_CALL, RPAREN, SUPER_CTOR_CALL"/> -->
        <module name="ParenPad">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_whitespace.html -->
        <!-- Checks the policy on the padding of parentheses for typecasts. -->
        <!-- <property name="option" value="nospace"/> -->
        <!-- <property name="tokens" value="TYPECAST, RPAREN"/> -->
        <module name="TypecastParenPad">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_whitespace.html -->
        <!-- Checks that a token is followed by whitespace. -->
        <!-- <property name="tokens" value="COMMA, SEMI, TYPECAST"/> -->
        <module name="WhitespaceAfter">
            <property name="tokens" value="COMMA, SEMI, TYPECAST" />
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_whitespace.html -->
        <!-- Checks that a token is surrounded by whitespace. -->
        <!-- <property name="tokens" value="ASSIGN, BAND, BAND_ASSIGN, BOR, BOR_ASSIGN, BSR, BSR_ASSIGN, BXOR, BXOR_ASSIGN, COLON, DIV, DIV_ASSIGN, EQUAL, GE, GT, LAND, LCURLY, LE, LITERAL_ASSERT, LITERAL_CATCH, 
            LITERAL_DO, LITERAL_ELSE, LITERAL_FINALLY, LITERAL_FOR, LITERAL_IF, LITERAL_RETURN, 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"/> -->
        <module name="WhitespaceAround">
            <property name="allowEmptyLambdas" value="true" />
            <property name="allowEmptyTypes" value="true" />
        </module>

        <!-- http://checkstyle.sourceforge.net/config_whitespace.html -->
        <!-- <module name="GenericWhitespace"/> -->

        <!-- See http://checkstyle.sourceforge.net/config_modifiers.html -->
        <!-- Checks that the order of modifiers conforms to the suggestions in the Java Language specification, sections 8.1.1, 8.3.1 and 8.4.3. -->
        <module name="ModifierOrder">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_modifiers.html -->
        <!-- Checks that there is no redundant modifiers. -->
        <!-- <property name="tokens" value="METHOD_DEF, VARIABLE_DEF"/> -->
        <module name="RedundantModifier">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_blocks.html -->
        <!-- Checks for empty blocks. -->
        <!-- <property name="option" value="stmt"/> -->
        <!-- <property name="tokens" value="LITERAL_CATCH, LITERAL_DO, LITERAL_ELSE, LITERAL_FINALLY, LITERAL_IF, LITERAL_FOR, LITERAL_TRY, LITERAL_WHILE, INSTANCE_INIT STATIC_INIT"/> -->
        <module name="EmptyBlock">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_blocks.html -->
        <!-- Checks for the placement of left curly braces ('{') for code blocks. -->
        <!-- <property name="option" value="eol"/> -->
        <!-- <property name="tokens" value="CLASS_DEF, CTOR_DEF, INTERFACE_DEF, LITERAL_CATCH, LITERAL_DO, LITERAL_ELSE, LITERAL_FINALLY, LITERAL_FOR, LITERAL_IF, LITERAL_SWITCH, LITERAL_SYNCHRONIZED, 
            LITERAL_TRY, LITERAL_WHILE, METHOD_DEF"/> -->
        <module name="LeftCurly">
            <property name="option" value="nl" />
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_blocks.html -->
        <!-- Checks for braces around code blocks. -->
        <!-- <property name="tokens" value="LITERAL_DO, LITERAL_ELSE, LITERAL_IF, LITERAL_FOR, LITERAL_WHILE"/> -->
        <module name="NeedBraces">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_blocks.html -->
        <!-- Checks the placement of right curly braces ('}') for else, try, and catch tokens. -->
        <!-- <property name="option" value="same"/> -->
        <!-- <property name="tokens" value="LITERAL_CATCH, LITERAL_ELSE, LITERAL_TRY"/> -->
        <module name="RightCurly">
            <property name="option" value="alone" />
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_blocks.html -->
        <!-- Finds nested blocks, i.e. blocks that are used freely in the code. -->
        <!-- <property name="allowInSwitchCase" value="false"/> -->
        <module name="AvoidNestedBlocks">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Checks that array initialization contains a trailing comma. -->
        <!-- <module name="ArrayTrailingComma"> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Detects inline conditionals. -->
        <!--<module name="AvoidInlineConditionals"> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Checks that classes that define a covariant equals() method also override method equals(java.lang.Object). -->
        <module name="CovariantEquals">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Detects empty statements (standalone ;). -->
        <module name="EmptyStatement">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Checks that classes that override equals() also override hashCode(). -->
        <module name="EqualsHashCode">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Checks that local variables that never have their values changed are declared final. -->
        <!-- <property name="tokens" value="PARAMETER_DEF, VARIABLE_DEF"/> -->
        <!-- <module name="FinalLocalVariable"> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Checks that a local variable or a parameter does not shadow a field that is defined in the same class. -->
        <!-- <property name="tokens" value="PARAMETER_DEF, VARIABLE_DEF"/> -->
        <!-- <property name="ignoreFormat" value=""/> -->
        <!-- <property name="ignoreConstructorParameter" value="false"/> -->
        <!-- <property name="ignoreSetter" value="false"/> -->
        <!--<module name="HiddenField"> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Checks for illegal instantiations where a factory method is preferred. -->
        <!-- <property name="classes" value="java.lang.Boolean"/> -->
        <module name="IllegalInstantiation">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Checks for illegal tokens. -->
        <!-- <property name="tokens" value="LITERAL_SWITCH, POST_INC, POST_DEC"/> -->
        <!--<module name="IllegalToken"> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Checks for illegal token text. -->
        <!-- <property name="tokens" value=""/> -->
        <!-- <property name="format" value=""/> -->
        <!-- <property name="ignoreCase" value="false"/> -->
        <!-- <property name="message" value=""/> -->

        <module name="IllegalTokenText">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Checks for assignments in subexpressions, such as in String s = Integer.toString(i = 2);. -->
        <!-- <property name="tokens" value="ASSIGN, BAND_ASSIGN, BOR_ASSIGN, BSR_ASSIGN, BXOR_ASSIGN, DIV_ASSIGN, MINUS_ASSIGN, MOD_ASSIGN, PLUS_ASSIGN, SL_ASSIGN, SR_ASSIGN, STAR_ASSIGN"/> -->
        <module name="InnerAssignment">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Checks that there are no "magic numbers", where a magic number is a numeric literal that is not defined as a constant. -->
        <!-- <property name="tokens" value="NUM_DOUBLE, NUM_FLOAT, NUM_INT, NUM_LONG"/> -->
        <!-- <property name="ignoreNumbers" value="-1, 0, 1, 2"/> -->
        <module name="MagicNumber">
            <property name="ignoreNumbers" value="-1, 0, 1, 2, 3, 100" />
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Checks that switch statement has "default" clause. -->
        <module name="MissingSwitchDefault">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Checks for overly complicated boolean expressions. -->
        <module name="SimplifyBooleanExpression">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Checks for overly complicated boolean return statements. -->
        <module name="SimplifyBooleanReturn">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Checks that string literals are not used with == or !=. -->
        <module name="StringLiteralEquality">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Restricts nested if-else blocks to a specified depth (default = 1). -->
        <!-- <property name="max" value="1"/> -->
        <module name="NestedIfDepth">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Restricts nested try-catch blocks to a specified depth (default = 1). -->
        <!-- <property name="max" value="1"/> -->
        <module name="NestedTryDepth">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Checks that an overriding clone() method invokes super.clone(). -->
        <module name="SuperClone">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Checks that an overriding finalize() method invokes super.finalize(). -->
        <module name="SuperFinalize">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Catching java.lang.Exception, java.lang.Error or java.lang.RuntimeException is almost never acceptable. -->
        <!-- <property name="illegalClassNames" value="java.lang.Exception, java.lang.Throwable, java.lang.RuntimeException"/> -->
        <!--<module name="IllegalCatch"> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Ensure a class is has a package declaration. -->
        <module name="PackageDeclaration">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Restrict the number of return statements. Default = 2. -->
        <!-- <property name="max" value="2"/> -->
        <!--<module name="ReturnCount"> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Checks that particular class are never used as types in variable declarations, return values or parameters. -->
        <!-- <property name="tokens" value="PARAMETER_DEF, VARIABLE_DEF METHOD_DEF"/> -->
        <!-- <property name="illegalClassNames" value=" java.util.GregorianCalendar, java.util.Hashtable, java.util.HashSet, java.util.HashMap, java.util.ArrayList, java.util.LinkedList, java.util.LinkedHashMap, 
            java.util.LinkedHashSet, java.util.TreeSet, java.util.TreeMap, java.util.Vector"/> -->
        <!-- <property name="ignoredMethodNames" value="getInitialContext, getEnvironment"/> -->
        <module name="IllegalType">
            <property name="illegalClassNames"
                value="
                    java.util.GregorianCalendar, java.util.Hashtable,
                    java.util.HashSet, java.util.HashMap, java.util.ArrayList,
                    java.util.LinkedHashMap,
                    java.util.LinkedHashSet " />
            <property name="legalAbstractClassNames" value="AbstractWrappedValueModel, AbstractValueModel, AbstractHyperlinkAction" />
            <property name="tokens" value="ANNOTATION_FIELD_DEF, INTERFACE_DEF, METHOD_CALL, METHOD_DEF, METHOD_REF, PARAMETER_DEF, VARIABLE_DEF"/>
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Checks declaration order according to Code Conventions for the Java Programming Language. -->
        <!-- <module name="DeclarationOrder"> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Disallow assignment of parameters. -->
        <module name="ParameterAssignment">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Checks if any class or object member explicitly initialized to default for its type value. -->
        <module name="ExplicitInitialization">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Check that the default is after all the cases in a switch statement. -->
        <module name="DefaultComesLast">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Checks that classes (except abtract one) define a ctor and don't rely on the default one. -->
        <!--<module name="MissingCtor"> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Checks for fall through in switch statements Finds locations where a case contains Java code - but lacks a break, return, throw or continue statement. -->
        <module name="FallThrough">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Checks that each variable declaration is in its own statement and on its own line. -->
        <module name="MultipleVariableDeclarations">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Checks that code doesn't rely on the "this." default. -->
        <!-- <property name="checkFields" value="true"/> -->
        <!-- <property name="checkMethods" value="true"/> -->
        <!-- <module name="RequireThis"> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_coding.html -->
        <!-- Checks for the use of unnecessary parentheses. -->
        <module name="UnnecessaryParentheses">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_design.html -->
        <!-- Checks visibility of class members. -->
        <!-- <property name="packageAllowed" value="false"/> -->
        <!-- <property name="protectedAllowed" value="false"/> -->
        <!-- <property name="publicMemberPattern" value="^serialVersionUID"/> -->
        <module name="VisibilityModifier">
            <property name="packageAllowed" value="true" />
            <property name="protectedAllowed" value="true" />
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_design.html -->
        <!-- Checks that a class which has only private constructors is declared as final. -->
        <!-- <module name="FinalClass"> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_design.html -->
        <!-- Make sure that utility classes (classes that contain only static methods) do not have a public constructor. -->
        <!-- <module name="HideUtilityClassConstructor"> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_design.html -->
        <!-- Checks that classes are designed for extension. -->
        <!-- <module name="DesignForExtension"> </module> TODO [team2aab] research -->

        <!-- See http://checkstyle.sourceforge.net/config_design.html -->
        <!-- Ensures that exceptions (defined as any class name conforming to some regular expression) are immutable. That is, have only final fields. -->
        <!-- <property name="format" value="^.*Exception$|^.*Error$"/> -->
        <!--<module name="MutableException"> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_design.html -->
        <!-- Restricts throws statements to a specified count (default = 1). -->
        <!-- <property name="max" value="1"/> -->
        <module name="ThrowsCount">
            <property name="max" value="3" />
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_metrics.html -->
        <!-- Restrict the number of number of &&, || and ^ in an expression. -->
        <!-- <property name="max" value="3"/> -->
        <!--<module name="BooleanExpressionComplexity"> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_metrics.html -->
        <!-- This metric measures the number of instantiations of other classes within the given class. -->
        <!-- <property name="max" value="7"/> -->
        <!--<module name="ClassDataAbstractionCoupling"> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_metrics.html -->
        <!-- The number of other classes a given class relies on. -->
        <!-- <property name="max" value="20"/> -->
        <!--<module name="ClassFanOutComplexity"> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_metrics.html -->
        <!-- Checks cyclomatic complexity against a specified limit. -->
        <!-- <property name="max" value="10"/> -->
        <!--<module name="CyclomaticComplexity"> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_metrics.html -->
        <!-- The NPATH metric computes the number of possible execution paths through a function. -->
        <!-- <property name="max" value="200"/> -->
        <module name="NPathComplexity">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_misc.html -->


        <!-- A generic check for code problems - the user can search for any pattern. -->
        <!-- <property name="format" value="^$"/> -->
        <!-- <property name="ignoreCase" value="false"/> -->
        <!-- <property name="ignoreComments" value="false"/> -->
        <!-- <property name="message" value=""/> -->
        <!--<module name="GenericIllegalRegexp"> <property name="ignoreComments" value="true"/> <property name="format" value="\S\s+$"/> <property name="message" value="Line has trailing spaces."/> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_misc.html -->
        <!-- A check for TODO: comments. Actually it is a generic regular expression matcher on Java comments. To check for other patterns in Java comments, set property format. -->
        <!-- <property name="format" value="TODO:"/> -->
        <module name="TodoComment">
            <property name="format" value="TODO" />
            <property name="severity" value="info" />
        </module>
        <module name="TodoComment">
            <property name="format" value="FIXME" />
            <property name="severity" value="info" />
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_misc.html -->
        <!-- Checks that long constants are defined with an upper ell. That is 'L' and not 'l'. -->
        <module name="UpperEll">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_misc.html -->
        <!-- Checks the style of array type definitions. -->
        <!-- <property name="javaStyle" value="true"/> -->
        <module name="ArrayTypeStyle">
        </module>

        <!-- See http://checkstyle.sourceforge.net/config_misc.html -->
        <!-- Check that method/constructor parameters are final. -->
        <!-- <property name="tokens" value="METHOD_DEF, CTOR_DEF"/> -->
        <!--module name="FinalParameters"> </module -->

        <!-- See http://checkstyle.sourceforge.net/config_misc.html -->
        <!-- Checks for restricted tokens beneath other tokens. -->
        <!-- <property name="tokens" value=""/> -->
        <!-- <property name="limitedTokens" value=""/> -->
        <!-- <property name="minimumDepth" value="0"/> -->


        <!-- <property name="maximumDepth" value="java.lang.Integer.MAX_VALUE"/> -->
        <!-- <property name="minimumNumber" value="0"/> -->


        <!-- <property name="maximumNumber" value="java.lang.Integer.MAX_VALUE"/> -->
        <!-- <property name="minimumMessage" value="descendant.token.min"/> -->
        <!-- <property name="maximumMessage" value="descendant.token.max"/> -->
        <!-- <module name="DescendantToken"> </module> -->

        <!-- See http://checkstyle.sourceforge.net/config_misc.html -->
        <!-- Checks correct indentation of Java Code. -->
        <!-- <property name="basicOffset" value="4"/> -->
        <!-- <property name="braceAdjustment" value="0"/> -->
        <!-- <property name="caseIndent" value="4"/> -->
        <!-- <module name="Indentation"> </module> TODO [team2aab] setup this check for our code -->

        <!-- See http://checkstyle.sourceforge.net/config_misc.html -->
        <!-- The check to ensure that requires that comments be the only thing on a line. -->
        <!-- <property name="format" value="^[\\s\\}\\);]*$"/> -->
        <!--<module name="TrailingComment"> </module> -->

    </module>
    
    <module name="SuppressWithPlainTextCommentFilter">
        <property name="offCommentFormat" value="CSOFF" />
        <property name="onCommentFormat" value="CSON" />
    </module>

    <module name="RegexpMultiline">
        <property name="format" value="^\s*\n\s*[\n}]" />
        <property name="message" value="Redundant blank line(s)" />
        <property name="fileExtensions" value="java" />
    </module>

    <module name="RegexpMultiline">
        <property name="format" value="\{\s*\n\s*\n" />
        <property name="message" value="Line is followed by redundant blank line(s)" />
        <property name="fileExtensions" value="java" />
    </module>

    <module name="RegexpSingleline">
        <property name="format" value="^\t" />
        <property name="message" value="Indentations must use spaces characters" />
    </module>

    <module name="RegexpSingleline">
        <property name="format" value="^(?!\s+\* $).*?\s+$" />
        <property name="message" value="Line has trailing spaces" />
    </module>

    <module name="RegexpSingleline">
        <property name="format" value="^(?!((\s{4})*\S)|((\s{4})*\s\*)).+" />
        <property name="message" value="Indentations must be of 4 spaces each" />
    </module>

    <!-- See http://checkstyle.sourceforge.net/config_duplicates.html -->
    <!-- Performs a line-by-line comparison of all code lines and reports duplicate code. -->
    <!-- <property name="min" value="12"/> -->
    <!-- <module name="StrictDuplicateCode"> </module> -->

    <!-- See http://checkstyle.sourceforge.net/config_misc.html#Translation -->
    <!-- Checks that property files contain the same keys. -->
    <!-- <property name="fileExtensions" value="properties"/> -->

    <!--
    <module name="Translation">
    </module>
    -->

</module>