【作者】 吴尚；

【导师】 潘昊；

【作者基本信息】 武汉理工大学 ， 计算机应用技术， 2005， 硕士

【摘要】 Java 2平台企业版定义了多层企业应用程序的标准。J2EE通过提供标准化,模块化的组件,并为这些组件提供完整的服务,简化了企业应用的开发,从而避免了进行复杂的程序设计。J2EE的核心规范是Enterprise Java Bean(EJBs)。这是因为EJB服务端组件模型简化了具有交互性、可扩展性和移植性中间件的开发。在采用EJB技术的J2EE项目中,EJB架构的设计好坏将直接影响系统的性能、可扩展性、可维护性、可重用性以及开发效率。项目越复杂,项目队伍越庞大则越能体现良好设计的重要性。 设计模式是一套被反复使用、经过分类编目的代码设计经验的总结。使用设计模式可以提高代码的可重用性和可靠性,并且让代码更容易被他人理解。本论文研究了Rose框架下的EJB设计模式及其在项目中的应用。为了能够在Java和J2EE开发平台下更好的进行软件开发,我们自主研发出了一个通用的技术框架—Rose,它实际上也是为了提高开发的通用性和再利用性提供的一种面向对象的软件环境。Rose框架提供了各种各样的技术标准,例如:GUI API,异常处理API,EJB,Java消息服务(JMS),事务处理API,JavaMail等等。这里主要剖析EJB在ROSE框架下是如何设计、实现和部署的。 在本论文中首先详细介绍了Rose框架下的EJB的分类和它们各自的组成。然后详细讨论了本论文的核心部分:EJB的四个设计模式SessionBean Facade模式,Command模式,Date Object模式,Version Lock模式,以及两个数据处理方法:数据缓冲和数据转换。并通过实例来进行演示说明。由于EJB框架要考虑到大型系统中事务安全等各方面问题,在效率性能方面有所欠缺,Rose框架下的EJB设计模式则可以弥补这些问题。通过灵活运用Rose框架下的EJB设计模式,不但能够提高代码重用性和可拓展性,更重要的是大大提高了系统的执行效率。更多还原

【Abstract】 The Java 2 Platform, Enterprise Edition (J2EE) defines the standard for developing multitier enterprise applications. The J2EE platform simplifies enterprise applications by basing them on standardized, modular components, by providing a complete set of services to those components, and by handling many details of application behavior automatically, without complex programming. The core of the J2EE is EJB - Enterprise Java Bean which is the Enterprise Application component. The EJB Design Patterns is very important for the whole system. And whether the EJB design patterns is better or not impact the efficiency and performance, expansibility, maintainability, reusability of the application directly.A pattern as a best practice solution to a common recurring problem . That is ,a pattern documents and explains an important or challenging problem that can occur when designing or implementing an application , and then dicusses a best practice solution to that problem . Of course there are many uses of patterns . In order to design the pattern of EJB better, we use a new framework - ROSE which stands for Reusable Object-oriented Software Environment. It is a common foundation framework developed in HIT for building applications based on Java and the J2EE platform. With ROSE, the development cycle can be significantly shortened and the application behavior can be far more consistent, there are many criterion of technology in Rose such as : GUI API, Exception API, EJB , JMS , JavaMail , ect .This document mainly aims to introduce four EJB design pattern : Session Facade Pattern .Command Pattern .Version Lock Pattern , Data Object Pattern . And two data handling :Data Conversion and Data Buffer. These patterns can reduce the workload of development for developers and make them focus on the business logic. At the same time .These patterns also improve the efficiency and performance of the application.更多还原