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C H A P T E R

Service Endpoint Design

W

EB

 services interact with clients to receive the clients' requests and return

responses. In between the request and the response, a Web service applies appropri 

ate business logic to process and fulfill a client's request. Designing an effective

Web service starts with understanding the nature of the service to be provided that

is, how the service is going to interact with the client and how it is going to process

and fulfill the client's request coupled with how users of the service find and make

their requests. This chapter examines Web services from the perspective of a ser 

vice's interaction and processing functionality. 

The chapter describes the key issues you must consider when designing a Web

service, then shows how these considerations drive the design and implementation

of a service's Web service interface and functionality. In particular, the chapter

examines the interactions between a service and its clients and the business pro 

cessing that the service performs. It illustrates these considerations by drawing

from examples using three typical Web service scenarios. 

The chapter covers most of the decisions that must be made when designing

and implementing a Web service, including identifying the different possibilities

that give rise to different solutions. It describes how to receive requests, delegate

requests to business logic, formulate responses, publish a Web service, and handle

document based interactions. 

Along the way, the chapter makes recommendations and offers some guide 

lines for designing a Web service. These recommendations and key points,

marked with check boxes, include discussions of justifications and trade offs.

They are illustrated with the example service scenarios. Since Web services basi 

cally expose interoperable interfaces for new as well as existing applications, a

large segment of the audience of this book may have existing applications for

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