Develop Java Web Services to Access Databases

Web services are distributed application components that are externally useful and available. Web services are language and platform independent because vendors have agreed on common Web service standards. A complete Web services stack, Metro, developed by Sun Microsystems, covers all of a developer’s needs from simple Java Web services demonstrations to reliable, secure and transacted web services. Metro includes Web Services Interoperability Technologies (WSIT). WSIT supports enterprise features such as security, reliability and message optimization. REST-based or RESTful Web services are collections of Web resources identified by URIs. Every document and process is modeled as a Web resource with a unique URI. In SOAP-based Web services, Java utilities create a WSDL file based on the Java code in the Web service. The WSDL is exposed on the net. Parties interested in using the Web service create a Java client based on the WSDL. Messages are exchanged in SOAP format.