Java Collections API Change Summary

We received many excellent suggestions concerning previous Beta releases of the collections API. Suggestions came from companies, universities, and individuals all around the world. The total traffic on the collections-comments mailbox was about 550 typewritten pages. We're truly thankful for these suggestions, and we've incorporated many of them into the Beta3 API. This page summarizes the differences between the Beta2 and Beta3 releases, along with a brief rationale for each change.

The big news here is that we've added two new core collection interfaces, SortedMap and SortedSet. While we regret upping the interface count from four to six, we think they pull their weight, for reasons outlined below. For increased power, these new interfaces contain several methods that weren't in TreeMap. Other notable changes include the addition of TreeSet and the deletion of ArraySet and ArrayMap.

Core Collection Interfaces - Collection

Core Collection Interfaces - List

Core Collection Interfaces - Map

Core Collection Interfaces - SortedMap, SortedSet

Concrete Implementations

Two concrete implementation that did not pull their weight were unceremoniously eliminated, and one new one (TreeSet, referred to above), was added. While not an API change, it is worth noting that serialization now works for all of general-purpose Collection Implementations.


Algorithms and Array Operations

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