A number of extensions to the TLS protocol have been proposed mainly in RFC 3546 and RFC 4366, which provides both generic extension mechanisms for the TLS handshake client and server hellos, and specific extensions using these generic mechanisms, such as server name indication, maximum fragment length negotiation, trusted CA indication. The extensions introduced in this RFC are designed to enable TLS to operate as effectively as possible in new environments like wireless networks.

RFC4366 is a revision of RFC3546. RFC3546 is designed for TLS 1.0. RFC4366 is designed for both TLS 1.0 and 1.1, with a few new extensions compared to RFC3546.

Both RFCs should be considered while implementing the RFE.

JSSE should be compatible with the TLS extensions generic mechanisms at least. And it would be better if some specific extensions, such as server name indication, are supported by JSSE APIs.
New TLS extension specification, RFC 6066.