The Java SDK version 2.2 is now Generally Available (GA), offering enhancements, bug fixes, and compatibility with Couchbase Server 4.0's new features. The release includes improvements to N1QL and Multi-Dimensional Scaling (MDS) support, enhanced durability, metrics for better monitoring, a simplified Object-Document Mapping (ODM) system, and API changes such as the switching from hot observables to cold ones, along with various naming changes and dependency upgrades. To get started with this release, users can update their pom.xml files or download the archive, which includes the com.couchbase.client/java-client/2.2.0 package. The javadocs and SDK documentation provide detailed information on the new features and changes.