Guava provides a core set of libraries for java which includes some of the latest and most commonly used one including graph library, functional types, hashing, primitives, APIs/utilities for concurrency with the new collections of multi-map and multi-set and much more.
It is definitely a great asset for beginners and other developers looking for high profile projects such as graphics and other functional types. It lists all the libraries with their functionalities so that it is easily understandable and fairly easy to implement as well.
Guava initially started on Sep 13, 2009 and has a good documentation on Wikipedia. It is implemented using java and currently has 670 open issues. So far 93 people have contributed to this project and currently it has 670 open issues. It helps to provide best coding practices and helps to reduce coding errors.
https://github.com/google/guava
Guava Example –
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