checkstyle.xml

<?xml version="1.0"?>
<!DOCTYPE module PUBLIC
    "-//Puppy Crawl//DTD Check Configuration 1.2//EN"
    "http://www.puppycrawl.com/dtds/configuration_1_2.dtd">

<module name="Checker">

	<!-- Checks whether files end with a new line. -->
	<module name="NewlineAtEndOfFile" />

	<!-- Checks that property files contain the same keys. -->
	<module name="Translation" />

	<!-- Avoid tab characters in the code -->
	<module name="FileTabCharacter" />

	<!-- <property name="WrapOp" value="nl"/> -->

	<module name="TreeWalker">

		<!-- Javadoc for methods must be present/valid. -->
		<module name="JavadocMethod">
			<property name="allowUndeclaredRTE" value="true" />
		</module>

		<!-- Javadoc for class variables must be present/valid. -->
		<module name="JavadocVariable" />

		<!-- Javadoc must be well-formed. -->
		<module name="JavadocStyle" />

		<!-- Naming conventions for packages. -->
		<module name="PackageName">
			<property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$" />
		</module>

		<!-- Naming conventions for classes and interfaces. -->
		<module name="TypeName" />

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

		<!-- Static variables name -->
		<module name="StaticVariableName">
			<property name="format" value="^[a-zA-Z][a-zA-Z0-9]*(_[a-zA-Z0-9]+)*$" />
		</module>

		<!-- Naming conventions for class variables. -->
		<module name="MemberName">
			<property name="format" value="^[a-z][a-zA-Z0-9]*_$" />
		</module>

		<!-- Naming conventions local variables. -->
		<module name="LocalFinalVariableName" />
		<module name="LocalVariableName" />
		<module name="ParameterName" />

		<!-- Avoid start imports -->
		<module name="AvoidStarImport" />

		<!-- Avoid imports of the sun.* packages -->
		<module name="IllegalImport" />

		<!-- Avoid redundant imports -->
		<module name="RedundantImport" />

		<!-- Avoid unused imports -->
		<module name="UnusedImports" />

		<!-- Ensure import order -->
		<module name="ImportOrder">
			<property name="groups" value="java,javax" />
			<property name="ordered" value="true" />
			<property name="separated" value="true" />
		</module>

		<!-- Lines should be maximum of 150 characters -->
		<module name="LineLength">
			<property name="max" value="150" />
			<property name="ignorePattern" value="^ *\* *[^ ]+$" />
			<property name="ignorePattern" value="^ *\@param*[^ ]+$" />
		</module>


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

		<!-- No whitespace after selected tokens -->
		<module name="NoWhitespaceAfter" />

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

		<!-- -->
		<module name="OperatorWrap">
			<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" />
			<property name="option" value="eol" />
		</module>

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

		<!-- No space in a case operation "(int)" not "( int )" -->
		<module name="TypecastParenPad">
			<property name="option" value="nospace" />
		</module>

		<!-- Space after comma, semicolon and casts -->
		<module name="WhitespaceAfter">
			<property name="tokens" value="COMMA, SEMI, TYPECAST" />
		</module>

		<!-- Ensure whitespace around all operators other than -->
		<!-- GENERIC_START and GENERIC_END -->
		<module name="WhitespaceAround">
			<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,
					 TYPE_EXTENSION_AND,
					 WILDCARD_TYPE" />
		</module>

		<!-- Check modifier order: -->
		<!-- public | protected | private -->
		<!-- abstract -->
		<!-- static -->
		<!-- final -->
		<!-- transient | volatile -->
		<!-- synchronized -->
		<!-- native -->
		<!-- strictfp -->
		<module name="ModifierOrder" />

		<!-- Avoid redundant modifiers -->
		<module name="RedundantModifier" />

		<!-- Avoid empty blocks -->
		<module name="EmptyBlock" />

		<!-- Classes, interfaces and methods have left brace on a new line -->
		<module name="LeftCurly">
			<property name="option" value="nl" />
			<property name="maxLineLength" value="120" />
			<property name="tokens"
				value="CLASS_DEF,
				       CTOR_DEF,
	                   INTERFACE_DEF,
					   METHOD_DEF,
					   LITERAL_CATCH,
                       LITERAL_DO,
                       LITERAL_ELSE,
                       LITERAL_FINALLY,
                       LITERAL_FOR,
                       LITERAL_IF,
                       LITERAL_SWITCH,
                       LITERAL_SYNCHRONIZED,
                       LITERAL_TRY,
                       LITERAL_WHILE" />
		</module>

		<!-- TODO -->
		<module name="RightCurly">
			<property name="option" value="alone" />
			<property name="tokens"
				value="LITERAL_CATCH,LITERAL_FINALLY, LITERAL_ELSE" />
		</module>

		<!-- Avoid nested blocks other than in switch statements -->
		<module name="AvoidNestedBlocks">
			<property name="allowInSwitchCase" value="true" />
		</module>

		<!-- Checks that classes that define a covariant equals() method -->
		<!-- also override method equals(java.lang.Object) -->
		<module name="CovariantEquals" />

		<!-- Avoid empty statements -->
		<module name="EmptyStatement" />

		<!-- Checks that classes that override equals() -->
		<!-- also override hashCode() -->
		<module name="EqualsHashCode" />

		<!-- Check that a name doens't hide another name -->
		<module name="HiddenField" />

		<!-- Avoid inner assignments -->
		<module name="InnerAssignment" />

		<!-- Require default clause in switch statements -->
		<module name="MissingSwitchDefault" />

		<!-- Avoid modifying control variables -->
		<module name="ModifiedControlVariable" />

		<!-- Avoid redundant throws -->
		<module name="RedundantThrows">
			<property name="allowUnchecked" value="true" />
		</module>

		<!-- Require simple boolean expressions -->
		<module name="SimplifyBooleanExpression" />

		<!-- Require simple boolean expressions -->
		<module name="SimplifyBooleanReturn" />

		<!-- Capture string compare using == -->
		<module name="StringLiteralEquality" />

		<!-- Checks that an overriding clone() method invokes super.clone() -->
		<module name="SuperClone" />

		<!-- Checks that an overriding finalize() method invokes -->
		<!-- super.finalize() -->
		<module name="SuperFinalize" />

		<!-- Disallow throwing exception base classes -->
		<module name="IllegalThrows">
			<property name="ignoredMethodNames"
				value="finalize,invoke,invokeAdvice,proceed,execute, aroundFileOutputStreamWriteOperation" />
		</module>

		<!-- Require all classes to be in a package -->
		<module name="PackageDeclaration" />

		<!-- Ensures correct layout of JUnit test cases -->
		<module name="JUnitTestCase" />

		<!-- Enforce the following declaration order: -->
		<!-- 1. Class variables -->
		<!-- 2. Instance variables -->
		<!-- 3. Ctors -->
		<!-- 4. Methods -->
		<module name="DeclarationOrder" />

		<!-- Disallow parameter assignment -->
		<module name="ParameterAssignment" />

		<!-- Ensure the default clasue is the last case in a switch -->
		<module name="DefaultComesLast" />

		<!-- Disallow non-commented swicth fall throug -->
		<module name="FallThrough" />

		<!-- Each variable should be declared individually -->
		<module name="MultipleVariableDeclarations" />

		<!-- Avoid unnecessary parantheses -->
		<module name="UnnecessaryParentheses" />

		<!-- Make sure only static finals are public -->
		<module name="VisibilityModifier" />

		<!-- Class with private constructor must be final -->
		<module name="FinalClass" />

		<!-- Utility classes should have private ctor -->
		<module name="HideUtilityClassConstructor" />

		<!-- Ensures that exception classes are immutable -->
		<module name="MutableException" />

		<!-- Flag overly complex constructions -->
		<module name="ClassFanOutComplexity">
			<property name="max" value="35" />
		</module>

		<module name="CyclomaticComplexity">
			<property name="max" value="35" />
		</module>
		<module name="NPathComplexity" />

		<!-- Identify TODOs -->
		<module name="TodoComment">
			<property name="format" value="TODO" />
		</module>

		<!-- Flag uncommented main() methods (debugging left-overs) -->
		<module name="UncommentedMain">
			<property name="excludedClasses" value="\.Main$" />
		</module>

		<!-- Require long constants to be defined by uppercase L -->
		<module name="UpperEll" />

		<!-- Array brackets on type not variable -->
		<module name="ArrayTypeStyle" />

		<!-- Avoid explicit initialization to the default value -->
		<module name="ExplicitInitialization" />

		<!-- Avoid trailing comments -->
		<module name="TrailingComment" />
	</module>
</module>