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Scenarios for Web Services Based Client Applications

burden on a network. Care must be taken to ensure data consistency between 

the service and the client. 

  Requiring complex computations on the client J2SE clients are well suited 

for performing complex mathematical calculations, as well as operations that 

update data, and then submitting the results to a service. For example, these cli 

ents have better resources for image manipulation, and they can relieve the 

server of this burden. Thus, J2SE clients can provide a better environment than 

a service for a user's interaction with data sets.

For example, a J2SE application may contain a rich GUI used to update

catalog information. The user can manipulate attributes as well as graphical data

using the application's GUI screens. When the user finishes, the application

submits new or updated catalog data to the catalog service.

J2SE applications may be deployed using Java Web Start technology. Java

Web Start simplifies deployment in large enterprise environments by ensuring that

clients have available the proper versions of the Java Runtime Environment and

all necessary libraries.

E

Whenever possible, use Java Web Start to provide a standardized means of de 

ployment for J2SE clients.

E

When designing a Web service client, try to keep Web service access code sep 

arate from GUI code.

E

Since J2SE clients may operate in either a connected or disconnected mode, 

when developing these clients keep in mind issues related to maintenance of 

state and client and service synchronization.

5.2.3 J2ME Clients

Java 2 Platform, Micro Edition (J2ME) clients may interact remotely with a Web

service. However, since J2ME clients have limited GUI capabilities compared to

J2SE clients, consider using J2ME clients when mobility and remote access are

requirements. Also consider using this type of client when immediacy of access is

important.

For example, Figure 5.4 shows a J2ME client running on a cell phone and

accessing an order tracking service. The client does not need an elaborate GUI or

set of widgets to interact with the Web service.