Even though JDK has a rich collection library, there are some 3rd-party libraries that provide more options, like the Apache Commons collections, Goldman Sachs collections, Google collections, Eclipse Collections, and Trove.

The Trove library is particularly useful because it provides high-speed regular and primitive collections for Java.

FastUtil is another similar API. It extends the Java Collections Framework by providing type-specific maps, sets, lists, and priority queues with a small memory footprint, fast access, and insertion; it also provides big (64-bit) arrays, sets, and lists, with fast, practical I/O classes for binary and text files.

Eclipse Collections is another useful open-course collections library that is worth learning. By the way, if you want to learn more about Java Collections, you can also check out Java Collections from basics to Advanced courses on Udemy.