checkstyle.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"/>

    <!-- Rationale: Any source files and text files in general should end with a line separator
         to let other easily add new content at the end of file and "diff" command does not
         show previous lines as changed.
         See http://checkstyle.sourceforge.net/config_misc.html#NewlineAtEndOfFile -->
    <module name="NewlineAtEndOfFile">
        <property name="lineSeparator" value="lf"/>
    </module>
    <!-- Checks for long source files. Default max: 2000                    -->
    <!-- See http://checkstyle.sourceforge.net/config_sizes.html#FileLength -->
    <module name="FileLength"/>
    <module name="FileTabCharacter"/>
    <!-- Checks that property files contain the same keys. -->
    <module name="Translation"/>

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

        <!-- Checks for Naming Conventions.                  -->
        <!-- See http://checkstyle.sf.net/config_naming.html -->
        <module name="ConstantName"/>
        <!-- local, final variables, including catch parameters -->
        <module name="LocalFinalVariableName"/>
        <module name="LocalVariableName"/>
        <module name="MemberName"/>
        <module name="MethodName"/>
        <!--<module name="PackageName"/>-->
        <module name="ParameterName"/>
        <module name="StaticVariableName"/>
        <!-- classes and interfaces -->
        <module name="TypeName"/>

        <!-- 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="LineLength">
            <property name="max" value="140"/>
        </module>
        <module name="MethodLength"/>
        <!--module name="ParameterNumber"/-->

        <!-- Checks for whitespace                               -->
        <!-- See http://checkstyle.sf.net/config_whitespace.html -->
        <module name="GenericWhitespace"/>
        <module name="EmptyForIteratorPad"/>
        <module name="MethodParamPad"/>
        <module name="NoWhitespaceAfter">
            <property name="tokens" value="BNOT, DEC, DOT, INC, LNOT, UNARY_MINUS, UNARY_PLUS"/>
        </module>
        <module name="NoWhitespaceBefore"/>
        <!-- Checks the policy on how to wrap lines on operators. -->
        <!-- <module name="OperatorWrap"/> -->
        <module name="ParenPad"/>
        <module name="TypecastParenPad"/>
        <!-- <module name="WhitespaceAfter"/> -->
        <module name="WhitespaceAround">
            <property name="allowEmptyConstructors" value="true"/>
            <property name="allowEmptyMethods" value="true"/>
            <property name="allowEmptyTypes" value="true"/>
            <property name="allowEmptyLoops" value="true"/>
        </module>
        <module name="SingleSpaceSeparator">
            <property name="validateComments" value="true"/>
        </module>

        <!-- Modifier Checks                                    -->
        <!-- See http://checkstyle.sf.net/config_modifiers.html -->
        <!-- Default order: public, protected, private, abstract, static, final, transient, volatile, synchronized, native, strictfp -->
        <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="EmptyBlock"/-->
        <!-- See http://checkstyle.sourceforge.net/config_blocks.html#LeftCurly -->
        <!-- <module name="LeftCurly"/> -->
        <!--module name="NeedBraces"/-->
        <!-- See http://checkstyle.sourceforge.net/property_types.html#rcurly#rcurly -->
        <!-- <module name="RightCurly"/> -->

        <!-- Checks for common coding problems               -->
        <!-- See http://checkstyle.sf.net/config_coding.html -->
        <!--module name="AvoidInlineConditionals"/-->
        <module name="CovariantEquals"/>
        <module name="EmptyStatement"/>
        <module name="EqualsAvoidNull"/>
        <module name="EqualsHashCode"/>
        <!--module name="HiddenField"/-->
        <module name="IllegalInstantiation"/>
        <!--module name="InnerAssignment"/-->
        <!--module name="MagicNumber"/-->
        <module name="MissingSwitchDefault"/>
        <!-- Checks for overly complicated boolean expressions. Currently finds code like  if (b == true), b || true, !false, etc.
             Rationale: Complex boolean logic makes code hard to understand and maintain. -->
        <module name="SimplifyBooleanExpression"/>
        <module name="SimplifyBooleanReturn"/>

        <!-- Checks for class design                         -->
        <!-- See http://checkstyle.sf.net/config_design.html -->
        <!--module name="DesignForExtension"/-->
        <!-- Checks that a class which has only private constructors is declared as final. -->
        <module name="FinalClass"/>
        <!--module name="HideUtilityClassConstructor"/-->
        <module name="InterfaceIsType"/>
        <!--module name="VisibilityModifier"/-->

        <!-- Miscellaneous other checks.                   -->
        <!-- See http://checkstyle.sf.net/config_misc.html -->
        <!-- Checks the style of array type definitions.
             Some like Java-style: public static void main(String[] args) and
             some like C-style: public static void main(String args[]) -->
        <module name="ArrayTypeStyle"/>
        <!--module name="FinalParameters"/-->
        <!--module name="TodoComment"/-->
        <module name="UpperEll"/>
        <!-- Checks correct indentation of Java code. Default basicOffset: 4 -->
        <module name="Indentation"/>
        <module name="CommentsIndentation"/>

        <module name="StringLiteralEquality"/>

        <module name="NestedIfDepth">
            <property name="max" value="3"/>
        </module>
        <module name="NestedTryDepth">
            <property name="max" value="2"/>
        </module>

    </module>
</module>