Maven Javadoc - Unable to generate Javadoc

Question

I have the following dependency and build in my pom file. I'm able to manually create the javadoc with a Maven command. I can also succesfully perform a build. The output doesn't mention javadoc at all. I've also tried leaving out the output directory paths. POM File Dependency section:

<dependency>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-javadoc-plugin</artifactId>
    <version>2.8</version>
</dependency>

and then the build section:

<build>
    <finalName>D</finalName>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-javadoc-plugin</artifactId>
            <version>2.8</version>
            <configuration> 
                <outputDirectory>${project.build.directory}/javadoc</outputDirectory>
                <reportOutputDirectory>${project.reporting.outputDirectory}/javadoc</reportOutputDirectory>
                <version>2.8</version>
            </configuration>
            <executions>
                <execution>
                    <id>attach-javadocs</id>
                    <goals>
                        <goal>aggregate</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

Answer 1

The Maven Javadoc plugin doesn't run by default and needs to be bound to one of the default Maven lifecycle phases.

Here's how I would write the plugin's configuration:

    <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-javadoc-plugin</artifactId>
        <version>2.8</version>
        <configuration> 
            <outputDirectory>${project.build.directory}/javadoc</outputDirectory>
            <reportOutputDirectory>${project.reporting.outputDirectory}/javadoc</reportOutputDirectory>
        </configuration>
        <executions>
            <execution>
                <id>attach-javadocs</id>
                <phase>site</phase>
                <goals>
                    <goal>aggregate</goal>
                </goals>
            </execution>
        </executions>
    </plugin>

Notice how I added an extra phase element to the execution. This will bind it to the "site" goal so that javadocs are generated when you run mvn site. Check Introduction to the Build Lifecycle if you want one of the default Java build phases.

Also note that I ditched the version parameter; by default, it should use your POM's version anyway.