Jakarta Web Services Metadata (JWS; formerly Web Services Metadata for Java platform and Java Web Services), as a part of Jakarta XML Web Services (JAX-WS), is a Java programming language specification (JSR-181) primarily used to standardize the development of web service interfaces for the Jakarta EE platform.

Using annotations from the JSR 181, you can annotate a Web service implementation class or a Web service interface. It enables developers to create portable Java Web Services from a simple plain old Java object (POJO) class by adding annotations, and also helps in generating a Web service with a wizard or by publishing the service on to a server.

Some of the annotations specified by this JSR are:

• @WebService
• @WebMethod
• @Oneway
• @WebParam
• @WebResult
• @HandlerChain
• @SOAPBinding

Put simply, JSR 181 is a specification to define standard and portable web services. It offers the following benefits:

• Provide a simplified model for developing web services
• Abstract the implementation details
• Achieve robustness, easy maintenance, and high interoperability^[1]

Version is 2.1 was released on December 15, 2009.^[2]