JAVA is a Sun product, made available to others. The benefit to Sun is that everyone can use and wants Java, and that helps it sell more Sun boxes - even though the customer doesn't HAVE to buy Sun. Companies allow staff to maintain packages, as part of aquiring that person, that skillset, and that package - supported on its hardware. This system gets used, configured, bridged, tested, supported and developed, my everone, and those focusing on their special interest group. Some of the material on sunsite is not distributable for copyright reasons, but is still available on the net.
Some material is duplicated, especially when included in more than one distribution.
Here are a few sites for you to try out and enjoy. Not sunsite There are mirrors of sunite, other hosts apart from sunsite, and there are URLS of pages of information indexing other sites and documents. Who's nightime, can give occasional connection refused, so look to see that the version you find is the one you're looking for, and check the date of the files. Some mirrors might only copy Incoming on a daily basis, and the installed files weekly. That is their mirroring policy, and is one of the reasons why different parts of the network go slow at different times.