eclipse does not respect suppression.xml file from maven-checkstyle-plugin

Question

I've using the maven-checkstyle-plugin (config see below) in version 3.2.1 for quite some time now and I'm also using a custom checkstyle.xml and suppressions.xml

e.g. in the suppressions.xml I have entries like:

<suppress files="messages.properties" checks="[a-zA-Z0-9]*"/>
<suppress files="target/generated-sources" checks=".*"/>

Since a few days, I see an error message in my eclipse (2023-03), e.g. in the above mentioned message.properties file:

(!) Line is longer then 120 characters (found xxx)
my.lang.key = a very long line with more then 120 chars, but this file should be ignored at all ...

The generated code in target/generated-sources/... is also clustered with checkstyle errors, although the files in this path should not be validated.

If I run a build on the console the build does not fail, hence the plugin is respecting the suppression.xml file, but the error flag in eclipse is still shown.

An update to maven-checkstyle-plugin:3.2.2 and checkstyle:10.11.0 (currently most recent versions) did not fix the problem.

Just another observation, I also have a new meta/config file in my project: .checkstyle, I suppose this is related ...?

<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-checkstyle-plugin</artifactId>
<version>3.2.1</version>
<dependencies>
    <dependency>
        <groupId>acme</groupId>
        <artifactId>checkstyle-config-cms</artifactId>
        <version>1.2.0</version>
    </dependency>
    <dependency>
        <groupId>com.puppycrawl.tools</groupId>
        <artifactId>checkstyle</artifactId>
        <version>10.6.0</version>
    </dependency>
</dependencies>
<configuration>
    <configLocation>checkstyle.xml</configLocation>
    <suppressionsLocation>suppressions.xml</suppressionsLocation>
    <inputEncoding>UTF-8</inputEncoding>
    <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>
</plugin>

Answer 1

Unfortunately, until now I did not come up with a better solution then to disable the checkstyle plugin within eclipse.

To do so, right click your project -> Checkstyle -> Deactivate Checkstyle

If the error is still shown you must clear your checkstyle violations. The maven run is not affected by this change and still is using checkstyle correctly.

---

Update (2024/01/24):

As it turns out you can avoid this problem when importing a project into eclipse (I'm using currently version: 2023-12 - freshly installed).

When I import a clean maven project that is using the checkstyle-maven-plugin into eclipse. I get a pop-up asking to setup a maven plugin connector.

Install Applies configuration from the maven-checkstyle-plugin to the Eclipse Checkstyle plugin. Disables execution of the maven-checkstyle-plugin within Eclipse in favor of the Eclipse plugin.

You probably can skip/cancel this, BUT if you are adding in advance some eclipse meta data information (see eclipse release-notes-17), e.g. <?m2e ignore?>

A new syntax has been introduced to simplify lifecycle mapping metadata for plugin executions, using processing instructions within plugin/executions/execution nodes.

Eclipse will not ask you to take control of the checkstyle handling and most probably will not make the above mentioned problems.

...
<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-checkstyle-plugin</artifactId>
  <version>3.3.1</version>
  <?m2e ignore?>
  ...