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Key Web Services Design Decisions

  Exposes an interface that clients use to make requests to the service

  Makes a service available to partners and interested clients by publishing the 

service details

  Receives requests from clients

  Delegates received requests to appropriate business logic and processes the 

requests

  Formulates and sends a response for the request

Given this flow of logic, the following are the typical steps for designing a

Web service.

1. Decide on the interface for clients. Decide whether and how to publish this 

interface.

You as the Web service developer start the design process by deciding on the 

interface your service makes public to clients. The interface should reflect the 

type and nature of the calls that clients will make to use the service. You should 

consider the type of endpoints you want to use EJB service endpoints or 

JAX RPC service endpoints and when to use them. You must also decide 

whether you are going to use SOAP handlers. Last, but not least, since one rea 

son for adding a Web service interface is to achieve interoperability, you must 

ensure that your design decisions do not affect the interoperability of the ser 

vice as a whole.

Next, you decide whether you want to publish the service interface, and, if so, 

how to publish it. Publishing a service makes it available to clients. You can 

restrict the service's availability to clients you have personally notified about 

the service, or you can make your service completely public and register it with 

a public registry. Note that it is not mandatory for you to publish details of your 

service, especially when you design your service for trusted partners and do not 

want to let others know about your service. Keep in mind, too, that restricting 

service details to trusted partners does not by itself automatically ensure secu 

rity. Effectively, you are making known the details about your service and its 

access only to partners rather than the general public.

2. Determine how to receive and preprocess requests.

Once you've decided on the interface and, if needed, how to make it available, 

you are ready to consider how to receive requests from clients. You need to de 

sign your service to not only receive a call that a client has made, but also to