Web services allow us to write functionality that can be accessed across a network in a language- and platform-independent way.

There are two different approaches that are frequently used to develop web services: the first approach is to use the Simple Object Access Protocol (SOAP) and the second approach is to use the Representational State Transfer (REST) protocol. NetBeans supports creating web services using either approach. SOAP web services are covered in this chapter. RESTful web services were covered in the previous chapter.

When using the SOAP protocol, web service operations are defined in an XML document called a Web Services Definition Language (WSDL) file. After creating the WSDL file, an implementation of web services is performed in a proper programming language such as Java. The process of creating a WSDL is complex and error-prone; fortunately, when working with Java EE, a WSDL file can be automatically generated from a web service written in Java...