java/checkstyle.xml

<?xml version="1.0" ?>
<!--
  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 "-//Checkstyle//DTD Checkstyle Configuration 1.2//EN" "https://checkstyle.org/dtds/configuration_1_2.dtd">

<module name="Checker">
  <module name="SuppressionFilter">
    <property name="file" value="checkstyle-suppressions.xml"/>
  </module>
  <module name="FileTabCharacter">
    <property name="eachLine" value="true"/>
  </module>
  <module name="NewlineAtEndOfFile">
  </module>
  <module name="LineLength">
    <property name="max" value="100"/>
    <property name="ignorePattern" value="a href|https://|^ +\* .*$|^ *// .*$|throw new IllegalArgumentException"/>
  </module>
  <module name="RegexpSingleline">
    <property name="format" value="\s+$"/>
    <property name="message" value="No trailing white space allowed."/>
  </module>
  <module name="TreeWalker">
    <module name="OuterTypeFilename"/>
    <module name="CommentsIndentation"/>
    <module name="AvoidStarImport">
      <property name="allowClassImports" value="false"/>
      <property name="allowStaticMemberImports" value="false"/>
    </module>
    <module name="UnusedImports"/>
    <module name="RedundantImport"/>
    <!-- https://checkstyle.sourceforge.io/config_imports.html#ImportOrder IntelliJ default example -->
    <module name="CustomImportOrder">
      <property name="customImportOrderRules" value="THIRD_PARTY_PACKAGE###SPECIAL_IMPORTS###STANDARD_JAVA_PACKAGE###STATIC"/>
      <property name="specialImportsRegExp" value="^javax\."/>
      <property name="standardPackageRegExp" value="^java\."/>
      <property name="sortImportsInGroupAlphabetically" value="true"/>
      <property name="separateLineBetweenGroups" value="false"/>
    </module>
    <module name="ModifierOrder"/>
    <module name="RedundantModifier"/>
    <module name="NoLineWrap"/>
    <module name="OneStatementPerLine"/>
    <module name="NeedBraces">
      <property name="allowSingleLineStatement" value="true"/>
    </module>
    <module name="UpperEll"/>
    <module name="ArrayTypeStyle"/>
    <module name="RegexpSinglelineJava">
      <property name="format" value="^\s+(&amp;&amp;|[|][|])"/>
      <property name="ignoreComments" value="true"/>
      <property name="message" value="No starting LAND and LOR allowed."/>
    </module>
    <module name="Indentation">
      <property name="severity" value="error"/>
      <property name="basicOffset" value="2"/>
      <property name="braceAdjustment" value="0"/>
      <property name="caseIndent" value="2"/>
      <property name="throwsIndent" value="2"/>
      <property name="lineWrappingIndentation" value="4"/>
      <property name="arrayInitIndent" value="2"/>
    </module>
  </module>
</module>