IBM Workplace Client Technology Micro Edition Version 5.7.1: Application Development and Case Study

Chapter 2. The Case Study: ITSO Car Rentals 19

򐂰 Data such as flight information from the airlines and other external sources is

used as a core process. How is this data obtained and updated to the device?

2.1.2 Information infrastructure

The sample application will be used by employees of the ITSO Rentals company.

The application’s panels are viewed using a browser on a handheld device. The

application’s main panel displays two groups of information. The top group has

an HTML table that lists rental customers expected to arrive in the near future.

The bottom group contains customers who have arrived but have not yet left the

rental location. Ideally this application is used by the ITSO Rentals shuttle driver

who picks up the customers at the airport terminal and takes them to their vehicle

in the rental company’s parking lot.

When a customer is picked up at the airport by the company shuttle driver, the

driver finds the customer's name, and picture in the top table, then checks the

box next to their entry. When the Submit button is selected, the application

updates the customer’s status in the local database, sending a message to the

host server telling it that this customer has arrived.

The customer’s name will now be displayed in the bottom table of the application,

but it is possible that the exact location of the renter's vehicle is not available yet.

When the host server sends a response to the message mentioned above, it will

indicate in which parking space the renter's vehicle is located. The next time the

application screen is updated, the location will then be displayed. The bus driver

can then take the customer directly to his or her car.

The application also checks the latest flight information for the arriving

customers. If an arriving flight is delayed or cancelled, then the application will

highlight that information with a background color for the bus driver.

A host server in this scenario will contain information about all the customers the

company has. However, recall the data requirements. The handheld device the

bus driver uses holds only a small subset of all the customers arriving in the near

future. The application will be able to synchronize that subset of the host

database with the use of Sync button. The driver will use this button periodically

to send locally stored updates to the server and to collect any updates from the

server.

20 WCTME: Application Development and Case Study

Figure 2-1 The big picture

Let us look at the data structures. The database has three tables. One for

customers, one for contracts, and one for flight information. The database is

loaded with customer and contract information in this example. In a real

production environment, these tables would be updated by reservation agents to

add customers and rental contracts, updated by car service workers to record

what slot number a car is in, and other information such as the status of the

customer based on the actions of the shuttle driver.

Aside from the customer data, there is also a table for flight information.

Generally, a car rental agency would not maintain flight information, but for the

purposes of this case study, our database will have flight information to allow the

system to determine if a customer’s flight is delayed, cancelled or on time. As

you will see further on, we decided to interact with this database through a Web

Service, because in the real world, it is very possible the airlines would provide

this information as a Web service. As a Web Service, it can also be accessed

from other nonITSO Rentals-supported devices, such as MIDP devices. It might

be a public service from the airlines that MIDlets can access real time flight

information from a Web service so travelers, from their MIDP phones, can find

out if their flights are on schedule. This is what we have done in Appendix C,

“Sample server-side Web Service” on page 375.

The business process we modeled works something like this:

Web

Service

Client

MQe Server

Database Sync

Device Services

DB2e

Sync

MQe

Client

DB2e

Access

WEA Server

WAS

Web Service

DB2

DB2e

Server

Pocket PC

Device

Sync

Web

Service

(Offline)

Flight Delays

Car Slots

Customer ID

Name

Photo

Contract

ID Cust ID

Flight Info

Car Slot

Status

Pending

On bus

Exited

Flight

Flight info

Status

On time

Delayed

Cancelled

TABLES