checkstyle.xml

<!--
  Copyright 2015 Philadelphia 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://checkstyle.sourceforge.net/dtds/configuration_1_3.dtd">
<module name="Checker">
  <property name="charset" value="UTF-8" />
  <property name="fileExtensions" value="java" />

  <!-- Ignore generated sources. -->
  <module name="BeforeExecutionExclusionFileFilter">
    <property name="fileNamePattern" value="target/generated-sources" />
  </module>

  <!-- No tabs. -->
  <module name="FileTabCharacter">
    <property name="eachLine" value="true" />
  </module>

  <!-- No trailing whitespace. -->
  <module name="RegexpSingleline">
    <property name="format" value="\s+$" />
    <property name="message" value="Line must not contain trailing whitespace" />
  </module>

  <module name="TreeWalker">

    <module name="ImportOrder">

      <!-- Static imports at the top. -->
      <property name="option" value="top" />

      <!-- Type imports in alphabetical order. -->
      <property name="ordered" value="true" />

      <!-- An empty line between static imports and type imports. -->
      <property name="separatedStaticGroups" value="true" />

      <!-- Static imports in alphabetical order. -->
      <property name="sortStaticImportsAlphabetically" value="true" />
    </module>

    <!-- No unused imports. -->
    <module name="UnusedImports" />

    <!-- No unused local variables. -->
    <module name="UnusedLocalVariable" />
  </module>
</module>