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">
	<module name="TreeWalker">
		<module name="LeftCurly">
			<property name="option" value="nl"/>
		</module>
		<!-- require tabs for indenting - https://stackoverflow.com/a/28550141 -->
		<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="WhitespaceAround">
			<property name="tokens" value="LITERAL_IF, LITERAL_ELSE, LITERAL_WHILE, LITERAL_DO, LITERAL_FOR, DO_WHILE"/>
		</module>
	</module>
	<module name="SuppressionFilter">
		<property name="file" value="suppressions.xml"/>
	</module>
</module>