checkstyle.xml

<?xml version="1.0"?>
<!DOCTYPE module PUBLIC
	"-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
	"https://checkstyle.org/dtds/configuration_1_3.dtd">

<module name="Checker">
	<module name="TreeWalker">
		<module name="Indentation">
			<property name="basicOffset" value="8"/>
			<property name="braceAdjustment" value="0"/>
			<property name="caseIndent" value="8"/>
			<property name="throwsIndent" value="8"/>
			<property name="arrayInitIndent" value="4"/>
			<property name="lineWrappingIndentation" value="4"/>
		</module>
		<module name="EmptyLineSeparator">
			<property name="tokens"
					  value="PACKAGE_DEF, IMPORT, CLASS_DEF, INTERFACE_DEF, ENUM_DEF, STATIC_INIT, INSTANCE_INIT, METHOD_DEF, CTOR_DEF"/>
		</module>
		<module name="LeftCurly">
			<property name="option" value="eol"/>
		</module>
		<module name="NeedBraces"/>
		<module name="WhitespaceAfter"/>
		<module name="WhitespaceAround"/>
		<module name="UnusedImports"/>
		<module name="SuppressionCommentFilter"/>
		<module name="RegexpSinglelineJava">
			<property name="format" value="^\t* "/>
			<property name="message" value="Indent must use tab characters"/>
			<property name="ignoreComments" value="true"/>
		</module>
	</module>
	<module name="NewlineAtEndOfFile"/>
</module>