Chapter 3 Service Endpoint Design

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mas, and mapping documents to domain objects be performed as close to the 

service endpoint as possible, and certainly in the service interaction layer. 

A design such as this helps to catch errors early, and thus avoids unnecessary

calls and round trips to the processing layer. Figure 3.4 shows the recommended

way to handle requests and responses in the Web service's interaction layer.

The Web service's interaction layer handles all incoming requests and dele 

gates them to the business logic exposed in the processing layer. When imple 

mented in this manner, the Web service interaction layer has several advantages,

since it gives you a common location for the following tasks:

  Managing the handling of requests so that the service endpoint serves as the 

initial point of contact

  Invoking security services, including authentication and authorization

  Validating and transforming incoming XML documents and mapping XML 

documents to domain objects

Service Interaction Layer

Service Processing Layer

Web Service Endpoint

XML Document 

er

Preprocessing

Validation

ng

Transformation

aramet P essi

Deassembling

est

rocP

Java type input parameter

Web

equR

Service

Clients

XML Document 

eter

Postprocessing

Transformation

aram

Caching

Assembling

rocessingP

esponse P

Java type output parameter

R

Figure 3.4

Web Service Request Processing