JAX-WS

JAX-WS, the Java API for XML Web Services, is the specification for building and consuming SOAP-based web services in Java. It lets developers define a service as annotated Java classes and generates the WSDL and XML messaging plumbing underneath, mapping Java method calls to SOAP requests and responses. Now maintained as Jakarta XML Web Services under the Eclipse Foundation, it was a core part of the Java EE and Jakarta EE web-services stack.

• SOAP-based - Speaks the XML-and-WSDL protocol stack rather than plain HTTP/JSON REST.
• Contract from code or WSDL - Supports both code-first and contract-first development styles.
• Annotation-driven - Uses Java annotations to expose classes and methods as web service operations.
• Standardized tooling - Consistent generation of clients and stubs across compatible runtimes.

In API operations, JAX-WS represents the SOAP era that many enterprises still run in production, particularly in finance, telecom, and government integrations. These services predate OpenAPI and REST conventions, so governing and modernizing them usually means documenting their WSDL contracts, wrapping them behind REST or gateway facades, and bringing their operations into discoverable catalogs. Recognizing JAX-WS in an estate is often the first signal that legacy SOAP surface needs to be inventoried before it can be made agent-ready.