The JCA 1.6 specification (JSR-322) final release was published on Dec 2009, and it has been included in Java EE 6 specification. The JCA 1.6 specification is backward compatible with the previous JCA specifications. That means the JCA Adapters that were developed under JCA 1.5 can move to JCA 1.6 smoothly.
Some new features were introduced in JCA specification 1.6, such as:
Ease of Development (EoD): It simplifies the development of JCA Resource Adapter by leveraging the metadata annotations, and reduces the need for ra.xml descriptor.
Generic Work Context: A generic mechanism for Resource Adapter to propagate useful contextual information from EIS to end point during message delivery.
Security Inflow: It enables an end-to-end security model for Java EE application and EIS integration.
Miscellaneous improvements: Some other improvements have also been done on transaction management, work management, message inflow etc.