Eclipse Collections 10.0 Released

Donald Raab
Oracle Developers
Published in
2 min readJul 14, 2019


README: The features you want with the collections you need

Thank you to the contributors

Eclipse Collections 9.2 was released in May 2018. The 9.x releases were extremely feature rich and had many contributions from the community. The 10.0 release is even more so. There were 18 contributors in the 10.0 release. This is outstanding! Thank you so much to all of the contributors who donated their valuable time to making Eclipse Collections more feature rich and even higher quality. Your efforts are very much appreciated.

Too many features for one blog

There are so many features included in Eclipse Collections 10.0, that it is going to take me a bit longer to write good examples leveraging all of them. So I have decided to break this release blog into a few parts. This part will purely be a summary.

Update: Detailed Feature Blogs

The Feature Summary

  1. Specialized Interfaces for MultiReaderList/Bag/Set
  2. Implement Stream for Primitive Lists
  3. Implement toMap with target Map
  4. Implement MutableMapIterable.removeAllKeys
  5. Implement RichIterable.toBiMap
  6. Implement Multimap.collectKeyMultiValues
  7. Implement fromStream(Stream) on collection factories
  8. Implement LazyIterate.cartesianProduct
  9. Add updateValues to primitive maps
  10. Implement MutableMultimap.getIfAbsentPutAll
  11. Implement Bag.collectWithOccurrences
  12. Add reduce and reduceIfEmpty for primitive iterables
  13. Add <type1><type2>To<type1>Function for primitives
  14. Add ofInitialCapacity to primitive maps
  15. Implement countByEach on RichIterable
  16. Implement UnifiedSetWithHashingStrategy.addOrReplace
  17. Implement UnmodifiableMutableOrderedMap
  18. Implement withAllKeyValues on mutable primitive maps.
  19. Add ability to create PrimitivePrimitive/PrimitiveObject/ObjectPrimitiveMap from Iterable
  20. Implement ofInitialCapacity and withInitialCapacity in HashingStrategySets
  21. Implement getAny on RichIterable
  22. Revamp and standardize resize/rehash for all primitive hash structures
  23. Implement factory methods to convert Iterable<BoxedPrimitive> to PrimitiveStack/Bag/List/Set
  24. Implement ImmutableSortedBagMultimapFactory in Multimaps
  25. Implement a Map factory method that takes a Map parameter.
  26. Wildcard type in MultableMultimap.putAllPairs & add methods

Check out the latest JavaDoc for the new features.

Other Improvements

  1. Improved Test Coverage
  2. Many build improvements
  3. Remove duplicate code
  4. Removed some deprecated classes
  5. Improved generics
  6. Some new benchmark tests
  7. And much more!

Thank you

From all the contributors and committers… thank you for using Eclipse Collections. We hope you enjoy all of the new features and improvements in the 10.0 release.

I’ll be publishing detailed examples for the new features in the 10.0 release in a few blogs. Stay tuned!

I am a Project Lead and Committer for the Eclipse Collections OSS project at the Eclipse Foundation. Eclipse Collections is open for contributions. If you like the library, you can let us know by starring it on GitHub.



Donald Raab
Oracle Developers

Java Champion. Creator of the Eclipse Collections OSS Java library ( Inspired by Smalltalk. Opinions are my own.