Web Development with MyEclipse and JBoss – part 2
Design of the EJB Project
In the section below we will explain various aspects of J2EE technology. The design should be understood
as a technology overview introducing technologies like Entity Beans with Container Managed Persistence
(CMP) and design patterns like Data Access Objects (DAO).
As explained earlier in this document, we are using a central Session Bean to implement our business
logic. We will implement two of the use cases introduced in Part One of this three part series:
• Login User
• Local Dealership Inquiry ( for browsing items which are available in stock)
The Login User use case is implemented as a method in the WebStockAccess Session Bean. This bean will be
responsible for authenticating the user by communicating with the database using a Data Access Object
(DAO) which encapsulates the Java Database Connectivity (JDBC) code. In fact, we do not want to
implement the JDBC query directly in this Session Bean method, but move it to a Data Access Object
(DAO). There are a several advantages to using this design:
• First, we have clean separation between our business logic and the underlying JDBC
exceptions and connections.
• Second, in the case where we change the underlying database technology, we only
have to check that our DAOs are still working. We do not have to worry about our
business logic.
• Third, we can implement database specific DAOs when we want to support multiple
database types.
The Local Dealership Inquiry use case is also implemented as a method in the WebStockAccess Session Bean.
The method returns a list of StockItems which are composite classes that include the information from an
Inventory class and an Item class. We moved the implementation into a DAO object, and the
implementation will use a Finder method of a CMP entity bean.
Enterprise Java Bean Development with MyEclipse
6
剩余27页未读，继续阅读
shuizhiling52
- 粉丝: 0
- 资源: 1
我的内容管理
展开
最新资源
- C++标准程序库：权威指南
- Java解惑：奇数判断误区与改进方法
- C++编程必读：20种设计模式详解与实战
- LM3S8962微控制器数据手册
- 51单片机C语言实战教程：从入门到精通
- Spring3.0权威指南：JavaEE6实战
- Win32多线程程序设计详解
- Lucene2.9.1开发全攻略：从环境配置到索引创建
- 内存虚拟硬盘技术：提升电脑速度的秘密武器
- Java操作数据库：保存与显示图片到数据库及页面
- ISO14001：2004环境管理体系要求详解
- ShopExV4.8二次开发详解
- 企业形象与产品推广一站式网站建设技术方案揭秘
- Shopex二次开发：触发器与控制器重定向技术详解
- FPGA开发实战指南：创新设计与进阶技巧
- ShopExV4.8二次开发入门：解决升级问题与功能扩展
资源上传下载、课程学习等过程中有任何疑问或建议，欢迎提出宝贵意见哦~我们会及时处理！
点击此处反馈
