The concept of a web service is rather simple; however, the implementation often faces many challenges from the technical aspects to the overall strategy of a business. This book places the emphasis on the technical implementation and technical challenges of a web service from the field. The book leads you through a journey of developing your first web service application to more complex multitier enterprise application. The examples include the use of commercially available software product such as Oracle Fusion Middleware and open source from the Apache Foundation. Through this journey, you will be able to understand and master a process that enable you to incorporate sound techniques to your web service application.

This book, which is based on lectures I provided at Trident University International, focuses more on the details of a hands-on approach to Web Service programming than its specifications; however, in order to help readers grasp the concept more easily, we provide a brief introduction to Web Service, SOAP, and WSDL in the first three chapters. Many details of the specifications are intentionally glossed over, however, so that the content remains manageable.

Web Service (WS) is a technology, process, and software paradigm that provides support for business integrations mainly over an Internet-based environment. This book presents basic concepts of WS, protocol stack, and applications. In addition to studying the three supporting standards SOAP, WSDL, and UDDI, students will learn how to implement WS using Java-centric technologies such as JAXP, JAXRPC, SAAJ, and JAXB. Students will also study how business processes can be implemented using WS via BPEL.

WS is a software application identified by a URI whose interfaces and binding are capable of being defined, described, and discovered by XML artifacts, and it supports direct interactions with other software applications using XML-based messages via Internet-based protocols (W3C: http:// www.w3.org/TR/ws-desc-reqs). WS is mainly for machine-to-machine communication. The WS standard relies on other standards – namely, SOAP, WSDL, and UDDI – to function efficiently. SOAP is an application protocol that is used to transmit messages between a WS client and a WS server. HTTP is the transport protocol of choice for SOAP; however, JMS and SMTP protocols have also been used. WSDL is used to describe the service that an external application can call. UDDI is used to publish and advertise services so that they can found and used by others. UDDI also uses SOAP as its application protocol.

The book focuses on the working mechanism of WS with a hands-on programming exercise using a basic Java WS framework. This framework works on a standalone Java application, an Oracle WebLogic Server (WLS), and an Apache Tomcat server. Thus, readers are expected to have sufficient knowledge of Java and XML.

Preface

List of Figures

Table of Listings

Table of Tables

1. Introduction
   1. Browsing the Internet
   2. Web Service architecture
   3. Benefits of Web Services
   4. Program a HelloWorld Web Service
   5. Host a Web Service
   6. Verify a Web Service
   7. Test a Web Service with SOAPUI
   8. Create a Web Service Client
   9. Run a Web Service Client
   10. References
2. SOAP
   1. Examples of SOAP messages
   2. Mapping SOAP to HTTP
   3. SAAJ Client
   4. Summary
   5. References
3. Web Service Description Language (WSDL)
   1. WSDL structure
   2. WSDL Interface
   3. WSDL Implementation
   4. References
4. A Sample Web Service Application
   1. A Sample application
   2. Develop a Web Service
   3. Deploy Web Services
   4. Check WSDL and XSD
   5. Test Web Services with SOAPUI
   6. Develope a Web Service Consumer
5. Apache CXF and Tomcat Server
   1. Configuration Parameters
   2. Apache Tomcat Server
   3. Develop CXF Web Service
   4. Deploy the Service
   5. Testing services with SOAPUI
   6. Develop a Web Service Consumer
6. Apache CXF and Oracle WebLogic Server
   1. Oracle WebLogic Server 12
   2. Deployment Diagram
   3. Creating a WebLogic Domain
   4. Deploy the Web Service
   5. Test CXF Web Service with WebLogic Test Tools
   6. Run the Client Application
7. Appendix A – Development Environment
   1. Install Java Development Kit (JDK) 6
   2. Install Eclipse Interactive Development Environment (IDE)
   3. Install MySQL Community Server Database
   4. Install Oracle Fusion Middleware Software
   5. Install Apache Tomcat server
   6. Apache CXF
   7. Install SOAPUI software
   8. Source Code
8. Endnotes