how to externalise the checkstyle config for maven-checkstyle-plugin

Question

I'm trying to make the maven-checkstyle-plugin use the same config file for all our projects.

I've tried a couple of ways, but non of them was effective.

The only thing that seems to work is when i place the config file at the root of my maven-project and then use the name as configLocation configuration parameter in the pom.xml

                <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-checkstyle-plugin</artifactId>
                <version>2.10</version>

                <configuration>
                    <configLocation>my-checkstyle-checker.xml</configLocation>
                </configuration>
            </plugin>

I've tried specifying an absolute disk-path, but that doesn't seem to work. (Considering the endgoal is to have jenkins do the checkstyle this seemed a valid option if the file would be on the jenkins server at the specified location)

I've also tried making a seperate jar-file only containing the xml-file and then using this as a dependency. (This would also centralise the config in 1 location and prevent project specific deviations.) Unfortunately this also doesn't work.

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-checkstyle-plugin:2.10:checkstyle (default-cli) on project jenkins-sandbox-project: An error has occurred in Checkstyle report generation. Failed during checkstyle execution: Unable to find configuration file at location my-checkstyle-checker.xml: Could not find resource 'my-checkstyle-checker.xml'. -> [Help 1]

Is there anyone that can tell me what i'm doing wrong here?

It seems it only knows about the files in the same location as where the maven command was started.

• maven-checkstyle-plugin version : 2.10
• maven command : mvn checkstyle:checkstyle

Answer 1

Create a separate Maven project, that contains just the Checkstyle configuration. In my case I called this project checkstyle-config and it contains the following:

checkstyle-config/src/main/resources/checkstyle.config.xml
checkstyle-config/src/main/resources/checkstyle.suppressions.xml
checkstyle-config/pom.xml

The POM file for this project is trivial:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.totaalsoftware.incidentmanager</groupId>
  <artifactId>checkstyle-config</artifactId>
  <version>2.0.0-SNAPSHOT</version>
</project>

Build it, so that it gets installed. Then use it as a dependency for your Checkstyle execution, e.g.:

  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-checkstyle-plugin</artifactId>
    <executions>
      <execution>
        <goals>
          <goal>check</goal>
        </goals>
      </execution>
    </executions>
    <dependencies>
      <dependency>
        <groupId>com.totaalsoftware.incidentmanager</groupId>
        <artifactId>checkstyle-config</artifactId>
        <version>2.0.0-SNAPSHOT</version>
      </dependency>
    </dependencies>
    <configuration>
      <configLocation>checkstyle.config.xml</configLocation>
      <suppressionsLocation>checkstyle.suppressions.xml</suppressionsLocation>

      ... other configuration ...

    </configuration>
  </plugin>

Answer 2

I had a similar problem. I solved it with the following configuration.

${project.basedir}/src/main/resources/checkstyle.xml

Note: my checkstyle file is located in "src/main/resources"

Answer 3

I also had some issues defining the location in my plugin configuration, but was able to get this working by overriding a Maven property that the plugin uses, checkstyle.config.location. See example below which works with a multi-module maven project and requires very little overhead.

<checkstyle.config.location>${project.parent.basedir}/my_checks.xml</checkstyle.config.location>