How to generate a combined Maven site from unrelated projects?

I would like to create a general overview of several Maven projects in the form of a website generated w开发者_C百科ith the Maven site goal. The projects are part of different products, some have a parent-child relation, some have dependencies on others.

The site should combine the information from all projects and include JavaDoc, Checkstyle/PMD checks, test results and code coverage metrics.

I've created a POM file that aggregates each existing project as a module, with each project available in subfolder, but then the output is not combined into a single site.

You can do this by setting project.build.directory on all of your projects to a common folder. This can be accomplished by passing in the path as a parameter to the build. You can then run the site goal on the common target folder. If you run maven from in a continuous integration environment, you can do this by setting targetpath in your maven task. Otherwise you would have to specify it on the command line.

<project>
  <build>
    <directory>${targetpath}/${project.artifactId}</directory>
    <plugins>
     <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-site-plugin</artifactId>
      <version>2.3</version>
      <configuration>
       <inputDirectory>${targetpath}</inputDirectory>
      </configuration>
     </plugin>
    </plugins>
  </build>
</project>

mvn clean deploy -Dtargetpath=Path/To/Build/Output

To keep the build the same for your developers, you could create a profile that is activated when targetpath is not provided by the command line.

<profiles>
  <profile>
    <id>dev</id>
    <activation>
      <property>
        <name>!targetpath</name>
      </property>
    </activation>
    <properties>
      <targetpath>target</targetpath>
    </properties>
  </profile>
</profiles>