Maven JavaDoc listed classes twice

Question

I am using the javadoc maven plugin and it creates the correct javadoc package, but all classes are created twice.

Maven dependency:

        <dependency>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-javadoc-plugin</artifactId>
        <version>3.3.0</version>
    </dependency>

My build code

<build>
            <plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-javadoc-plugin</artifactId>
                    <executions>
                        <execution>
                            <id>attach-javadocs</id>
                            <goals>
                                <goal>jar</goal>
                            </goals>
                        </execution>
                    </executions>
                </plugin>
            </plugins>
        </build>

Can anyone help me please, what am I missing here?

command usage for doc generation

mvn clean install -Dresources="FirstProject/example_API"

Answer 1

I noticed the same problem and came upon a solution after enabling debug on the maven-javadoc-plugin maven plugin and seeing what it's doing. Specifically setting the sourcepath as shown below fixed the double listing problem for me and I've tried this on multiple version of Corretto 8 as well as Temurin 8. All had the double listing problem because it's an issue with the javadoc tool itself but setting the sourcepath manually fixed it for me.

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-javadoc-plugin</artifactId>
    <version>3.3.1</version>
    <configuration>
        <debug>true</debug>
        <sourcepath>${basedir}/src/main/java</sourcepath>
    </configuration>
    <executions>
        <execution>
            <id>attach-javadocs</id>
            <goals>
                <goal>jar</goal>
            </goals>
        </execution>
    </executions>
</plugin>