HTTP is a synchronous request-response application network protocol. Client sends a request specifying one of the seven HTTP methods, the location of the resource to be invoked, a set of optional headers and an optional message body. The server sends back a response containing the version of HTTP we are using, a response code, a description of the response code, a set of optional headers, and an optional message body. HTTP is the primary protocol for most web applications on the Internet, regardless of whether they are written in Java, PHP or ASP. 

We will create a simple soap web service with richer data types ( List and a user defined class) using wsimport we will generate the client side stubs. In this lab, we will create an employee service that will return employee details based on employee numbers.

The jax-ws tools wsgen and wsimport generate artifacts for easy for web service development, deployment, and invocation.

Previously with JAX-RPC, frameworks like axis 1 had tools like wsdl1java and java2wsdl, but we should consider only jax-ws tools now.

The @SOAPBinding annotation can be used in a Service Endpoint Interface (SEI) to configure the soap binding style, encoding and parameter style; and we does this using style, use and parameterStyle attributes respectively.

WSDL stands for Web service Description Language. A WSDL document is a contract between a SOAP–based web service and its consumers. A WSDL document provides critical information such as service endpoint, service operations, data types required for operations, description of messages exchanged, and underlying service pattern (request/response, solicit/response etc). The WSDL document is useful for both creating and executing clients against a web service.