A Lightweight Enterprise Application Framework Design, Implementation And Applications,

By now,there is no consensus definition on framework.It is a most acceptable definition for lots of studies that framework is a reusable design of whole or partial application system, which is presented by Ralph Johnson.Framework, which decide application architecture, cliarify the dependency between collaborate component, assign responsibility,control process and provide context for reusing component, is a reusable design component.Classes assembly of default behaviour expected by applications is contained in framework.Concrete application can have special behaviour of itself by rewriting child class or composing classes. Compared with traditional object oriented reuse technique based on classes library,appplication framework is tend more to reuse software in professional area.To develop distributed application is very complicated and difficult because it usually involve large volume data which may come from many data sources. In multi-layer distributed applications,one or multi layers application service program,which is refered to as application server, can be located between client and server.Developers do not put business logic in client,but in application server.Thus isloate business logic with application UI interface and provide client a thinner ingerface.This also means devleopers only change code in application server when business logic changed,not lots of client applications.As a result,developers need only focus on designing,analysization and developing of core business logic in appliation .This smiplified the developing,udpating and upgrading of enterprise application and dramaticaly inhensed it's scalability and flexibility.Based on object oriented programming style,LEAF is a lightweight framework to help application developers create distributed applications. LEAF framework sufficiently use reflection,generics,remoting and attributes and provide distributed application powerful supports such as N-Level undo,PNP(plug and play) validated and authorized rules,data access gateway,and so on.Based on LEAF,developers can easily create business object and distributed system.