Skip to content

Maven Checkstyle Plugin

The current approach of Parent Project is providing all necessary configurations. Since the beginning version of Parent Project projects will include checkstyle configuration by default. This means every Maven build will require checkstyle checks. Builds that do not pass checkstyle check will fail.

Skipping in Local Builds

In order to skip checkstyle check in local builds, add the following parameter:

mvn clean install -Dcheckstyle.skip=true

Suppressions

If you want to exclude specific packages or classes, then add Maven properties for each module like:

<checkstyle.excludes>**/x/y/generated/GeneratedClass.java, **/generated/**</checkstyle.excludes>

Execution

To run only the checkstyle plugin:

mvn checkstyle:check

To run checkstyle as a profile:

mvn clean install -Pcheckstyle

How to Use Maven Checkstyle Plugin

This section includes extra information for custom configurations in some non-Parent Project based projects.

Configuration

To use it, configure your maven-checkstyle-plugin like so:

Define checkstyle properties on pom.xml and change them with your own values:


<properties>
  <!--checkstyle-->
  <yourcompany-checkstyle.version>${YOUR_YOURCOMPANY_CHECKSTYLE_VERSION}</yourcompany-checkstyle.version>
  <checkstyle.version>${YOUR_CHECKSTYLE_VERSION}</checkstyle.version>
  <maven-checkstyle-plugin.version>${YOUR_MAVEN_CHECKSTYLE_VERSION}</maven-checkstyle-plugin.version>
  <checkstyle.configLocation>/com/yourcompany/checkstyle/yourcompany_checks.xml</checkstyle.configLocation>
  <checkstyle.excludes>${YOUR_CHECKSTYLE_EXCLUDES}</checkstyle.excludes>
</properties>

If you want to check checkstyle on builds:


<build>
  <plugins>
    <!--checkstyle plugin-->
    <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-checkstyle-plugin</artifactId>
      <version>${maven-checkstyle-plugin.version}</version>
      <dependencies>
        <dependency>
          <groupId>com.yourcompany.checkstyle</groupId>
          <artifactId>yourcompany-checks</artifactId>
          <version>${yourcompany-checkstyle.version}</version>
        </dependency>
        <dependency>
          <groupId>com.puppycrawl.tools</groupId>
          <artifactId>checkstyle</artifactId>
          <version>${checkstyle.version}</version>
        </dependency>
      </dependencies>
      <configuration>
        <configLocation>${checkstyle.configLocation}</configLocation>
        <failOnViolation>true</failOnViolation>
        <violationSeverity>warning</violationSeverity>
        <includeTestSourceDirectory>true</includeTestSourceDirectory>
        <excludes>${checkstyle.excludes}</excludes>
        <outputFile>${project.build.directory}/checkstyle-result.xml</outputFile>
        <outputFileFormat>xml</outputFileFormat>
      </configuration>
      <executions>
        <execution>
          <id>validate</id>
          <phase>validate</phase>
          <goals>
            <goal>check</goal>
          </goals>
        </execution>
        <execution>
          <id>aggregate</id>
          <phase>verify</phase>
          <goals>
            <goal>checkstyle-aggregate</goal>
          </goals>
        </execution>
      </executions>
    </plugin>
  </plugins>
</build>

Using as a Profile


<profiles>
  <profile>
    <id>checkstyle</id>
    <build>
      <plugins>
        <!--checkstyle plugin-->
        <plugin>
          <groupId>org.apache.maven.plugins</groupId>
          <artifactId>maven-checkstyle-plugin</artifactId>
          <version>${maven-checkstyle-plugin.version}</version>
          <dependencies>
            <dependency>
              <groupId>com.yourcompany.checkstyle</groupId>
              <artifactId>yourcompany-checks</artifactId>
              <version>${yourcompany-checkstyle.version}</version>
            </dependency>
            <dependency>
              <groupId>com.puppycrawl.tools</groupId>
              <artifactId>checkstyle</artifactId>
              <version>${checkstyle.version}</version>
            </dependency>
          </dependencies>
          <configuration>
            <configLocation>${checkstyle.configLocation}</configLocation>
            <failOnViolation>true</failOnViolation>
            <violationSeverity>warning</violationSeverity>
            <includeTestSourceDirectory>true</includeTestSourceDirectory>
            <excludes>${checkstyle.excludes}</excludes>
            <outputFile>${project.build.directory}/checkstyle-result.xml</outputFile>
            <outputFileFormat>xml</outputFileFormat>
          </configuration>
          <executions>
            <execution>
              <id>validate</id>
              <phase>validate</phase>
              <goals>
                <goal>check</goal>
              </goals>
            </execution>
            <execution>
              <id>aggregate</id>
              <phase>verify</phase>
              <goals>
                <goal>checkstyle-aggregate</goal>
              </goals>
            </execution>
          </executions>
        </plugin>
      </plugins>
    </build>
  </profile>
</profiles>

See the maven-checkstyle-plugin documentation for more information about what the configuration settings mean.

Internally, we have the above configuration in the <pluginManagement/> section of a company-wide parent POM,
meaning that projects only need to specify the below in their <build><plugins> section:

<plugin>
  <artifactId>maven-checkstyle-plugin</artifactId>
</plugin>

Result

To see the checkstyle results after a Maven run, check the result file:

target/site/checkstyle-aggregate.html

Checkstyle Aggregate