[java] UnusedPrivateMethod for methods annotated with jakarta.annotation.PostConstruct or PreDestroy

[kdebski85]

Affects PMD Version:
7.3.0

Rule:

UnusedPrivateMethod
Description:

UnusedPrivateMethod should not be reported for methods annotated with jakarta.annotation.PostConstruct or jakarta.annotation.PreDestroy since they are usually called by a container (for example Spring).

As a workaround, the annotations can be added to configuration:

    <rule ref="category/java/bestpractices.xml/UnusedPrivateMethod">
        <properties>
            <property name="ignoredAnnotations" value="java.lang.Deprecated,jakarta.annotation.PostConstruct,jakarta.annotation.PreDestroy" />
        </properties>
    </rule>

However, I think such methods should be excluded by default.

Code Sample demonstrating the issue:

import jakarta.annotation.PostConstruct;
import jakarta.annotation.PreDestroy;
import org.springframework.stereotype.Component;

@Component
public class JakartaTest {

    @PostConstruct
    private void setup() {
    }

    @PreDestroy
    private void cleanup() {
    }
}

Expected outcome:

PMD reports a violation at lines 0 and 13, but that's wrong. That's a false positive.

Running PMD through: Gradle

[jsotuyod]

@kdebski85 thanks for the report! this looks like a great candidate for a contribution if you are up to it, I'd expect that same approach + the corresponding tests.

[kdebski85]

@jsotuyod I prepared #5118
Could you please review?