integrate JDK Source in eclipse

[Peter Horlock]

Hi,

I configured the maven-eclipse-plugin so that it downloades the sources and
JavaDocs of all third party jars:
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-eclipse-plugin</artifactId>
                <version>2.7</version>
                <configuration>
                    <downloadSources>true</downloadSources>
                    <downloadJavadocs>true</downloadJavadocs>
                    <useProjectReferences>true</useProjectReferences>
                </configuration>
            </plugin>

However, what I am still missing is the source for the JDK (6) itself.
How can that be automated?
 (I know how to do it manually, but then I have to do this for each and
every project each and everytime I import a project...)

Thanks in advance,

Peter