checkstyle.xml

<?xml version="1.0" encoding="UTF-8"?>
<!--
  ~ Copyright 2014-2018 the original author or authors.
  ~
  ~ Licensed under the Apache License, Version 2.0 (the "License");
  ~ you may not use this file except in compliance with the License.
  ~ You may obtain a copy of the License at
  ~
  ~     http://www.apache.org/licenses/LICENSE-2.0
  ~
  ~ Unless required by applicable law or agreed to in writing, software
  ~ distributed under the License is distributed on an "AS IS" BASIS,
  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  ~ See the License for the specific language governing permissions and
  ~ limitations under the License.
  -->

<!DOCTYPE module PUBLIC
    "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
    "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">
<module name="com.puppycrawl.tools.checkstyle.Checker">
    <!-- Root Checks -->
    <module name="com.puppycrawl.tools.checkstyle.checks.header.RegexpHeaderCheck">
        <property name="headerFile" value="${checkstyle.header.file}"/>
        <property name="fileExtensions" value="java"/>
    </module>
    <module name="com.puppycrawl.tools.checkstyle.checks.NewlineAtEndOfFileCheck">
        <property name="lineSeparator" value="lf"/>
    </module>

    <!-- TreeWalker Checks -->
    <module name="com.puppycrawl.tools.checkstyle.TreeWalker">
        <!-- Annotations -->
        <module name="com.puppycrawl.tools.checkstyle.checks.annotation.AnnotationUseStyleCheck">
            <property name="elementStyle" value="compact"/>
        </module>
        <module name="com.puppycrawl.tools.checkstyle.checks.annotation.MissingOverrideCheck"/>
        <module name="com.puppycrawl.tools.checkstyle.checks.annotation.PackageAnnotationCheck"/>
        <module name="com.puppycrawl.tools.checkstyle.checks.annotation.AnnotationLocationCheck">
            <property name="allowSamelineSingleParameterlessAnnotation" value="false"/>
        </module>

        <!-- Package -->
        <module name="com.puppycrawl.tools.checkstyle.checks.naming.PackageNameCheck">
            <property name="format" value="^de\.codecentric\.boot\.admin(\.[a-z][a-z0-9]*)*$"/>
        </module>

        <!-- Imports -->
        <module name="com.puppycrawl.tools.checkstyle.checks.imports.AvoidStarImportCheck"/>
        <module name="com.puppycrawl.tools.checkstyle.checks.imports.IllegalImportCheck">
            <property name="illegalPkgs"
                      value="sun, org.apache.commons.(?!codec|compress|dbcp2|lang|lang3|logging|pool2).*, com.google.common, org.flywaydb.core.internal, reactor.core.support.Assert"/>
            <property name="regexp" value="true"/>
        </module>
        <module name="com.puppycrawl.tools.checkstyle.checks.imports.RedundantImportCheck"/>
        <module name="com.puppycrawl.tools.checkstyle.checks.imports.UnusedImportsCheck">
            <property name="processJavadoc" value="true"/>
        </module>

        <!-- Miscellaneous -->
        <module name="com.puppycrawl.tools.checkstyle.checks.indentation.CommentsIndentationCheck">
            <property name="tokens" value="BLOCK_COMMENT_BEGIN"/>
        </module>
        <module name="com.puppycrawl.tools.checkstyle.checks.UpperEllCheck"/>
        <module name="com.puppycrawl.tools.checkstyle.checks.ArrayTypeStyleCheck"/>
        <module name="com.puppycrawl.tools.checkstyle.checks.OuterTypeFilenameCheck"/>

        <!-- Modifiers -->
        <module name="com.puppycrawl.tools.checkstyle.checks.modifier.RedundantModifierCheck"/>

        <!-- Regexp -->
        <module name="com.puppycrawl.tools.checkstyle.checks.regexp.RegexpSinglelineJavaCheck">
            <property name="maximum" value="0"/>
            <property name="format" value="org\.junit\.Assert\.assert"/>
            <property name="message"
                      value="Please use AssertJ imports."/>
            <property name="ignoreComments" value="true"/>
        </module>
        <module name="com.puppycrawl.tools.checkstyle.checks.regexp.RegexpCheck">
            <property name="format" value="[ \t]+$"/>
            <property name="illegalPattern" value="true"/>
            <property name="message" value="Trailing whitespace"/>
        </module>

        <!-- Whitespace -->
        <module name="com.puppycrawl.tools.checkstyle.checks.whitespace.GenericWhitespaceCheck"/>
        <module name="com.puppycrawl.tools.checkstyle.checks.whitespace.MethodParamPadCheck"/>
        <module name="com.puppycrawl.tools.checkstyle.checks.whitespace.NoWhitespaceAfterCheck">
            <property name="tokens" value="BNOT, DEC, DOT, INC, LNOT, UNARY_MINUS, UNARY_PLUS, ARRAY_DECLARATOR"/>
        </module>
        <module name="com.puppycrawl.tools.checkstyle.checks.whitespace.NoWhitespaceBeforeCheck"/>
        <module name="com.puppycrawl.tools.checkstyle.checks.whitespace.ParenPadCheck"/>
        <module name="com.puppycrawl.tools.checkstyle.checks.whitespace.TypecastParenPadCheck"/>
        <module name="com.puppycrawl.tools.checkstyle.checks.whitespace.WhitespaceAfterCheck"/>
        <module name="com.puppycrawl.tools.checkstyle.checks.whitespace.WhitespaceAroundCheck"/>
    </module>
</module>