How to build javadoc from sources within a .jar file?

Question

I have to build Javadoc from myCode.jar that contains both sources and class files. Can I do it without extracting the jar?

According to http://java.sun.com/j2se/1.5.0/docs/tooldocs/windows/javadoc.html#classpath I should be able to do so this way: C:\>javadoc -d docs -classpath myCode.jar net\kem\jmx\CacheManagerMBean.java However, I get the following error:

javadoc: error - File not found: "net\kem\jmx\CacheManagerMBean.java"
[search path for source files: [myCode.jar]]
[search path for class files: [C:\Program Files\Java\jdk1.5.0_17\jre\lib\rt.jar, C:\Program Files\Java\jdk1.5.0_17\jre\lib\jsse.jar,
 C:\Program Files\Java\jdk1.5.0_17\jre\lib\jce.jar, C:\Program Files\Java\jdk1.5.0_17\jre\lib\charsets.jar, C:\Program Files\Java\jd
k1.5.0_17\jre\lib\ext\dnsns.jar, C:\Program Files\Java\jdk1.5.0_17\jre\lib\ext\localedata.jar, C:\Program Files\Java\jdk1.5.0_17\jre
\lib\ext\sunjce_provider.jar, C:\Program Files\Java\jdk1.5.0_17\jre\lib\ext\sunpkcs11.jar, C:\Projects\RenderClusterController\WebCo
ntent\WEB-INF\lib\makoRenderJMX.jar]]
[done in 360 ms]
1 error

It seems, javadoc cannot find the source files within the jar. I'm confident that the sources are there.

Any suggestions?