The Java SDK 2.2 release introduces a range of new features and enhancements aimed at improving performance and usability for developers. Notable updates include enhanced N1QL support with an extended DSL for index management and collection predicates, simplified retry handling through helper classes, and the introduction of an Entity Mapping feature that allows for easier mapping between domain objects and Couchbase documents. Additionally, the release includes API enhancements such as a method to check for the existence of a key without fetching document content and a reintroduced bulk document retrieval option in view queries. Dependency updates, such as the upgrade to RxJava 1.0.9, have also been incorporated to ensure compatibility and performance improvements. The development team encourages feedback on these new features, particularly the Entity Mapping functionality, as they continue to refine the SDK with more forthcoming features.