checkstyle.xml

<?xml version="1.0" encoding="UTF-8"?>
<!--
  ~ Licensed to the Apache Software Foundation (ASF) under one or more
  ~ contributor license agreements.  See the NOTICE file distributed with
  ~ this work for additional information regarding copyright ownership.
  ~ The ASF licenses this file to You 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="Checker">
  <property name="charset" value="UTF-8"/>

  <property name="severity" value="error"/>

  <property name="fileExtensions" value="java"/>

  <module name="Header">
    <property name="headerFile" value="{{HEADER_FILE}}"/>
  </module>

  <module name="SuppressionFilter">
    <property name="file" value="checkstyle-suppressions.xml"/>
  </module>

  <module name="FileTabCharacter">
    <property name="eachLine" value="true"/>
  </module>

  <module name="RegexpSingleline">
    <property name="format" value="\s+$"/>
    <property name="message" value="No trailing whitespace allowed."/>
  </module>

  <module name="TreeWalker">
    <module name="OuterTypeFilename"/>
    <module name="IllegalTokenText">
      <property name="tokens" value="STRING_LITERAL, CHAR_LITERAL"/>
      <property name="format" value="\\u00(08|09|0(a|A)|0(c|C)|0(d|D)|22|27|5(C|c))|\\(0(10|11|12|14|15|42|47)|134)"/>
      <property name="message" value="Avoid using corresponding octal or Unicode escape."/>
    </module>
    <module name="AvoidEscapedUnicodeCharacters">
      <property name="allowEscapesForControlCharacters" value="true"/>
      <property name="allowByTailComment" value="true"/>
      <property name="allowNonPrintableEscapes" value="true"/>
      <property name="allowIfAllCharactersEscaped" value="true"/>
    </module>
    <module name="LineLength">
      <property name="max" value="100"/>
      <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
    </module>
    <module name="NoLineWrap"/>
    <module name="EmptyBlock">
      <property name="option" value="TEXT"/>
      <property name="tokens" value="LITERAL_TRY, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_SWITCH"/>
    </module>
    <module name="NeedBraces">
      <property name="allowSingleLineStatement" value="true"/>
    </module>
    <module name="OneStatementPerLine"/>
    <module name="ArrayTypeStyle"/>
    <module name="FallThrough"/>
    <module name="UpperEll"/>
    <module name="ModifierOrder"/>
    <module name="SeparatorWrap">
      <property name="tokens" value="DOT"/>
      <property name="option" value="nl"/>
    </module>
    <module name="SeparatorWrap">
      <property name="tokens" value="COMMA"/>
      <property name="option" value="EOL"/>
    </module>
    <module name="PackageName">
      <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$"/>
      <message key="name.invalidPattern" value="Package name ''{0}'' must match pattern ''{1}''."/>
    </module>
    <module name="ClassTypeParameterName">
      <property name="format" value="([A-Z][a-zA-Z0-9]*$)"/>
      <message key="name.invalidPattern" value="Class type name ''{0}'' must match pattern ''{1}''."/>
    </module>
    <module name="MethodTypeParameterName">
      <property name="format" value="([A-Z][a-zA-Z0-9]*)"/>
      <message key="name.invalidPattern" value="Method type name ''{0}'' must match pattern ''{1}''."/>
    </module>
    <module name="NoFinalizer"/>
    <module name="GenericWhitespace">
      <message key="ws.followed" value="GenericWhitespace ''{0}'' is followed by whitespace."/>
      <message key="ws.preceded" value="GenericWhitespace ''{0}'' is preceded with whitespace."/>
      <message key="ws.illegalFollow" value="GenericWhitespace ''{0}'' should followed by whitespace."/>
      <message key="ws.notPreceded" value="GenericWhitespace ''{0}'' is not preceded with whitespace."/>
    </module>
    <module name="ImportOrder">
      <property name="separated" value="true"/>
      <property name="ordered" value="true"/>
      <property name="groups" value="/^javax?\./,scala,*,org.apache.livy"/>
    </module>
    <module name="MethodParamPad"/>
    <module name="AnnotationLocation">
      <property name="tokens" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF"/>
    </module>
    <module name="AnnotationLocation">
      <property name="tokens" value="VARIABLE_DEF"/>
      <property name="allowSamelineMultipleAnnotations" value="true"/>
    </module>
    <module name="MethodName">
      <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9_]*$"/>
      <message key="name.invalidPattern" value="Method name ''{0}'' must match pattern ''{1}''."/>
    </module>
    <module name="EmptyCatchBlock">
      <property name="exceptionVariableName" value="expected"/>
    </module>
    <module name="CommentsIndentation"/>
  </module>
</module>