checkstyle.xml

<?xml version="1.0" encoding="UTF-8"?>
<!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"/>

	<module name="TreeWalker">
		<property name="fileExtensions" value="java"/>
		<property name="tabWidth" value="1"/>

		<!-- Force clean imports (no redundant and unused imports) -->
		<module name="RedundantImport"/>
		<module name="UnusedImports"/>

		<!-- Force tab indentation -->
		<module name="RegexpSinglelineJava">
			<property name="format" value="^\t* "/>
			<property name="message" value="Indent must use tab characters"/>
			<property name="ignoreComments" value="true"/>
		</module>

		<module name="OverloadMethodsDeclarationOrder"/>

		<module name="AvoidStarImport"/>
	</module>

	<module name="TreeWalker">
		<property name="fileExtensions" value="xml"/>
		<property name="tabWidth" value="1"/>
	</module>
	
</module>