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">
	<property name="charset" value="UTF-8" />
	<property name="fileExtensions" value="java, xml" />
	<property name="severity" value="warning" />

	<module name="FileLength" />
	<module name="NewlineAtEndOfFile" />

	<module name="TreeWalker">
		<property name="fileExtensions" value="java" />
		<property name="tabWidth" value="4" />

		<module name="AvoidNestedBlocks" />

		<module name="EmptyLineSeparator">
			<property name="allowMultipleEmptyLinesInsideClassMembers" value="false" />
			<property name="tokens"
				value="IMPORT, CLASS_DEF, INTERFACE_DEF, ENUM_DEF, STATIC_INIT, INSTANCE_INIT, METHOD_DEF, CTOR_DEF, VARIABLE_DEF" />
		</module>

		<module name="GenericWhitespace" />

		<module name="JavadocMethod">
			<property name="allowedAnnotations"
				value="Override, BeforeAll, BeforeEach, Test, AfterEach, AfterAll" />
			<property name="scope" value="protected" />
		</module>

		<module name="JavadocStyle" />
		<module name="JavadocType" />

		<module name="JavadocMethod">
			<property name="allowedAnnotations"
				value="Override, BeforeAll, BeforeEach, Test, AfterEach, AfterAll" />
			<property name="scope" value="protected" />
		</module>

		<module name="JavadocMethod">
			<property name="scope" value="private" />
			<property name="allowMissingJavadoc" value="true" />
		</module>

		<module name="EmptyBlock">
			<property name="option" value="text" />
		</module>

		<module name="LeftCurly" />

		<module name="LineLength">
			<property name="max" value="120" />
		</module>

		<module name="MethodParamPad" />
		<module name="NeedBraces" />

		<module name="Regexp">
			<property name="format" value="[ \t]+$" />
			<property name="illegalPattern" value="true" />
			<property name="message" value="Trailing whitespace" />
		</module>

		<module name="RightCurly">
			<property name="option" value="same" />
		</module>
	</module>
</module>