Web services provide the basic technical platform required for application interoperability. They do not, however, provide higher level control, such as which web services need to be invoked, which operations should be called and in what sequence. Nor do they provide ways to describe the semantics of interfaces, the workflows, or e-business processes. BPEL is the missing link to assemble and integrate web services into a real business process BPEL4WS standardizes process automation between web services. This applies both within the enterprise, where BPEL4WS is used to integrate previously isolated systems, and between enterprises, where BPEL4WS enables easier and more effective integration with business partners. In providing a standard descriptive structure BPEL4WS enables enterprises to define their business processes during the design phase. Wider business benefits can flow from this through business process optimization, reengineering, and the selection of most appropriate processes . Supported by major vendorsó including BEA, Hewlett-Packard, IBM, Microsoft, Novell, Oracle, SAP, Sun, and othersó BPEL4WS is becoming the accepted standard for business process management.
This book provides detailed coverage of BPEL4WS, its syntax, and where, and how, it is used. It begins with an overview of web services, showing both the foundation of, and need for, BPEL. The web services orchestration stack is explained, including standards such as WS-Security, WS-Coordination, WS-Transaction, WS-Addressing, and others. The BPEL language itself is explained in detail, with Code snippets and complete examples illustrating both its syntax and typical construction. Having covered BPEL itself, the book then goes on to show BPEL is used in context. by providing an overview of major BPEL4WS servers. It covers the Oracle BPEL Process Manager and Microsoft BizTalk Server 2004 in detail, and shows how to write BPEL4WS solutions using these servers.
Chapter 1 provides a detailed introduction to BPEL and Service Oriented Architecture (SOA). It discusses business processes and their automation, explains the role of BPEL, web services, and Enterprise Service Buses (ESB) in SOA, provides insight into business process composition with BPEL, explains the most important features, compares BPEL to other specifications, provides an overview of BPEL servers, and discusses the future of BPEL.
Chapter 2 provides a detailed introduction to the Web Services Technology Stack. It discusses the important standards and specifications for using BPEL and implementing SOA with web services, such as WS-Security, WS-Addressing, WS-Coordination, WS-AtomicTransaction, WS-BusinessActivity, WS-Reliable Messaging, etc.
Chapter 3 discusses the composition of web services with BPEL. The chapter introduces the core concepts of BPEL and explains how to define synchronous and asynchronous business processes with BPEL. The reader gets familiar with BPEL process structure, partner links, sequential and parallel service invocation, variables, conditions, etc.
Chapter 4 goes deeper into the BPEL specification and covers advanced features for modeling complex business processes. Advanced activities, scopes, serialization, fault handing, compensations, event handling, correlation sets, concurrent activities and links, process lifecycle, and dynamic partner links are covered in detail.
Chapter 5 explains how to use the Oracle BPEL Process Manager for deploying and executing business processes defined in BPEL. It describes the server architecture, tools, features, and common approaches for managing and debugging BPEL processes. The chapter also looks at graphical development of BPEL processes using Oracle BPEL Designer for JDeveloper and for Eclipse.
Chapter 6 takes a detailed look at the advanced features of the Oracle BPEL Process Manager including extension functions, dynamic parallel flows, Web Services Invocation Framework, Java embedding, Notification service, Workflow service, Identity service, and Oracle BPEL Server APIs.
Chapter 7 discusses MS BizTalk Server 2004 and its support for BPEL. It explains how to develop business processes in BizTalk and export them to BPEL. It also explains how to import BPEL processes into BizTalk and how to use the Orchestration Designer tool to define processes graphically, and compares BizTalk and BPEL constructs.
Appendix A provides a syntax reference for BPEL version 1.1. The appendix covers standard BPEL activities and elements, functions, attributes, and faults.