Use Oracle9i xml db to solve complicated coding problems

Developing Internet applications is complicated: You must not only define the behavior and logic of applications, but also combine multiple products, technical layers, and standards in a distributed environment. The sample code shows a variety of methods for developing Internet applications.

For example, consider the credit card verification feature that must be implemented by almost any Web site (such as PayPal) that wants to sell online. It mainly includes how to authenticate users, contact verification companies, and securely handle transactions-all of which combine the functionality of a Web-based thin client, a database, an application server, and an independent verification company the interaction between them is well combined.

OTN provides sample applications that use different combinations of products, technologies, and standards to solve such complex problems. Some examples use their own authentication mechanisms; others use the Single Sign-On (SSO) feature built into the Oracle 9i Application Server (Oracle 9iAS. OTN also provides a back-end application example that utilizes the xml db feature of the Oracle 9i Database.

The Web Service technology is used in each credit card sample application. By using Web Services, OTN developers can effectively build required functions into discrete components. This method is more flexible and easier to maintain because the application is modularized rather than integrated. Developers can change the implementation of components without affecting the main application, or use different components by modifying several lines of code. Therefore, Web services can be shared and reused between applications, and can be easily transplanted to enterprise-level grid computing environments when the time is ripe.

OTN members can download the following sample code (with any other sample code on OTN), study them, and mix and use these solutions according to their own development needs.

VSM in J2EE design mode

The Virtual Shopping Mall (VSM) sample application enables manufacturers to create online stores, allowing customers to browse all the stores, the system administrator can approve and reject new store applications and maintain the store category list. To build VSM, OTN developers have implemented several well-known J2EE design patterns, including Session Fa? Ade and Model-View-Controller (MVC ).

A module in the VSM guide series describes how OTN developers reuse a software component through Web Services. The credit card service component of VSM is implemented through three Java files: an interface that defines the component method (CCServices) and a class that implements this interface (CCServicesImpl ), and another exception class (CCException) that handles credit card verification failures ). Key operation-Verification of credit card numbers is performed by the CCServicesImpl. validateCard method, which uses the LUHN algorithm (also known as the model 10 algorithm ). Banks, enterprises, and other entities now use this rule extensively in the public domain to generate and verify credit cards, accounts, and ID card numbers.

1 2 Next Page

[Content navigation]
Page 1: Use Oracle9i xml db to solve complicated coding problems	Page 1: Use Oracle9i xml db to solve complicated coding problems