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">
	<module name="NewlineAtEndOfFile">
		<property name="fileExtensions" value="java, xml, pl, properties, php"/>
	</module>

	<!-- Check for trailing whitespace. -->
	<module name="RegexpSingleline">
		<property name="fileExtensions" value="java, xml, pl, properties, php"/>
		<property name="format" value="\s+$"/>
		<property name="message" value="Line has trailing spaces."/>
	</module>

	<!-- Space cannot be before tab character. -->
	<module name="RegexpSingleline">
		<property name="fileExtensions" value="java, xml, pl, properties, php"/>
		<property name="format" value=" +\t"/>
		<property name="message" value="Space before tab."/>
	</module>

	<module name="RegexpSingleline">
		<property name="fileExtensions" value="xml, pl, properties, php"/>
		<property name="format" value="^((?!\s*\*)\t* )"/>
		<property name="message" value="Indent must use tab characters."/>
	</module>

	<!-- This applies to java files only -->
	<module name="TreeWalker">

		<!-- Check if indents are done via tab char.
		<module name="RegexpSinglelineJava">
			<property name="format" value="^\t* "/>
			<property name="message" value="Indent must use tab characters."/>
			<property name="ignoreComments" value="true"/>
		</module>
		-->

		<!-- more complex indent check - recursive up to 10 indentation levels -->
		<!-- this is compliant with NetBeans and Intellij IDEA IDEs default java formatting styles -->
		<module name="Regexp">
			<property name="format"
			          value="^\t{1}[^\t\n]*\n+\t{2,} +|^\t{2}[^\t\n]*\n+(:?\t{0,1}|\t{3,}) +|^\t{3}[^\t\n]*\n+(:?\t{0,2}|\t{4,}) +|^\t{4}[^\t\n]*\n+(:?\t{0,3}|\t{5,}) +|^\t{5}[^\t\n]*\n+(:?\t{0,4}|\t{6,}) +|^\t{6}[^\t\n]*\n+(:?\t{0,5}|\t{7,}) +|^\t{7}[^\t\n]*\n+(:?\t{0,6}|\t{8,}) +|^\t{8}[^\t\n]*\n+(:?\t{0,7}|\t{9,}) +|^\t{9}[^\t\n]*\n+(:?\t{0,8}|\t{10,}) +|^\t{10}[^\t\n]*\n+(:?\t{0,9}|\t{11,}) +"/>
			<property name="illegalPattern" value="true"/>
			<property name="message" value="Wrong number of tabs before space on next line. Indent must use tab characters."/>
			<property name="ignoreComments" value="true"/>
		</module>

		<module name="RedundantImport"/>
		<module name="UnusedImports"/>

		<!-- Modifier Checks                                    -->
		<!--<module name="ModifierOrder"/>-->
		<!--<module name="RedundantModifier"/>-->

		<!-- Checks for blocks. You know, those {}'s         -->
		<!--<module name="LeftCurly"/>-->

		<!-- Checks for common coding problems               -->
		<!-- Disabled until http://sourceforge.net/tracker/?func=detail&aid=2843447&group_id=29721&atid=397078 is fixed-->
		<!--<module name="DoubleCheckedLocking"/>-->
		<!--<module name="EmptyStatement"/>-->
		<!--<module name="EqualsHashCode"/>-->
		<!--<module name="IllegalInstantiation"/>-->

		<!-- Miscellaneous other checks.                   -->
		<!--<module name="UpperEll"/>-->
		<!--<module name="PackageAnnotation"/>-->
		<!--<module name="CovariantEquals"/>-->
		<!--<module name="ArrayTypeStyle"/>-->

	</module>
</module>