artsok/custom-checkstyle-rules

Examples of how to develop custom CheckStyle rules

urp-checkstyle-rules

A set of additional checks to use with checkstyle.

Content

• Content
• Checks
  • MissingJavaDocMethodUrpCheck
  • IntermediateEmptyLinesCheck
  • EmptyLineAtTheEndChecker
  • AnnotationsWithoutEmptyLinesChecker
• Configuration
  • Maven dependency
  • Example checkstyle configuration
  • Example checkstyle maven plugin configuration
  • Example checkstyle gradle plugin configuration
• Why external lib

Checks

JavaDocMethodSizeCheck

Verify the JavaDoc at methods with configurable minimal amount of lines. Additionally, you could use a regular expression feature for class names, allowing you to ignore classes that don't match your specified pattern. Furthermore, this check is only applied to git changes made in your branch (Git should be installed).

Configuration

<module name="MissingJavaDocMethodUrpCheck">
  <property name="ignoreClassNamesRegex" value="WebClientConfig"/>
  <property name="accessModifiers" value="public,protected,package,private"/>
  <property name="fileExtensions" value="java"/>
  <property name="minLineCount" value="1"/>
</module>

Parameters

parameter name	type	default value	description
ignoreClassNamesRegex	int	12	TODO
minLineCount	int	7	TODO
accessModifiers	int	7	TODO

Configuration

Maven dependency

<dependency>
  <groupId>com.emirates.urp</groupId>
  <artifactId>urp-checkstyle-rules</artifactId>
  <version>1.0.0-SNAPSHOT</version>
</dependency>

Example checkstyle configuration

<?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">
  <module name="TreeWalker">
    <module name="FieldsCountCheck"/>
    <module name="MethodEmptyLines"/>
    <module name="MethodParameterAlignment"/>
    <module name="MethodParameterLines"/>
    <module name="MethodCallParameterAlignment"/>
    <module name="MethodCallParameterLines">
      <property name="ignoreMethods" value="Map.of"/>
    </module>
  </module>
</module>

Example checkstyle maven plugin configuration

To use check from this library with maven-checkstyle-plugin, you have to add the library as a maven dependency to the plugin.

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-checkstyle-plugin</artifactId>
  <version>3.2.0</version>
  <configuration>
    <configLocation>src/main/resources/checkstyle.xml</configLocation>
    <encoding>UTF-8</encoding>
    <consoleOutput>true</consoleOutput>
    <failsOnError>true</failsOnError>
    <linkXRef>false</linkXRef>
  </configuration>
  <executions>
    <execution>
      <id>validate</id>
      <phase>validate</phase>
      <goals>
        <goal>check</goal>
      </goals>
    </execution>
  </executions>
  <dependencies>
    <dependency>
      <groupId>com.emirates.urp</groupId>
      <artifactId>urp-checkstyle-rules</artifactId>
      <version>1.0.0-SNAPSHOT</version>
    </dependency>
  </dependencies>
</plugin>

Why external lib

The checkstyle is a powerful library that has many users, but I need some combo of existing rules.