I have the feeling that you're misinterpreting the purpose of design
patterns.  The amount of common code from a design pattern that could be
abstracted into a library is very small; probably less than a page.  The
idea behind the design pattern lies in how it organizes your own
functionality when you add to it later.  You may as well write that less
than a page of code on your own, rather than complicating deployment by
adding a dependency on a third-party library.  If you don't understand
the pattern well enough to implement it, then you're going to run into
problems anyway.

I'd actually go further, and recommend that you keep writing code and
reading about design patterns at arm's length.  Don't ever set out to
implement a design pattern.  A book on design patterns can give you some
ideas about how to resolve certain kinds of recurring problems, which
you should internalize so that you'll be able to use them organically in
your own designs, rather than producing stilted designs that are driven
by your choice of patterns.

Patterns are usually language neutral.

If you are looking for examples of standard patterns
like GoF patterns in Java then try:

http://www.fluffycat.com/java-design-patterns/
http://www.patterndepot.com/put/8/JavaPatterns.htm

Arne