On the JDK6 source page the repository link is broken, and the location that is described in readme doesn't exist. I know that there is also OpenJDK repository, but as I understand, it isn't the same.
I know how to download source files, but I'm much more interested in repository, not the jars.
I'm not interested in any other open implementations of JVM.
In the comments section of the readme, from the repository, you can see that's been a long time since people complain about the repository not being updated and with access problems.
Try downloading the .jar... as many others have suggested here.