J2EE框架介绍

Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,Introduction to J2EE,*,1,Introduction to,Java 2 Enterprise Edition,Presented by,Communication & Collaboration Technologies,Division of the Chief Information Officer,Rensselaer Polytechnic Institute,Welcome!,2,Main Topics,Introduction,The Goal,The Problem,The Solution,What is J2EE,?,The J2EE Framework,Case Studies,/,Examples,3,Introduction,“,Enterprises today need to extend their reach, reduce their costs, and lower their response times”,Simplified Guide to the Java 2 Platform, Enterprise Edition, Sun Microsystems, Inc.,4,Introduction,IT must provide:,High quality services,Highly Available,Secure,Scalable,Powerful services,Useful,Flexible,Extensible,Affordable,5,The Problem,produce,purchase,support,maintain,replace,Complex software is expensive to:,Difficult Tasks!,6,?,The Problem,Why not delegate components to different departments?,Departmental solutions are:,Limited in scope,Difficult to be aware of enterprise- wide requirements and initiatives,Difficult to leverage,Diverse interoperabilty standards,7,Cost and complexity,Solution: Leverage reusable software components,Limited scope and impact,Solution: Provide interfaces that enable enterprise-wide application development,Diverse standards,Solution: Utilize existing standards and software components,Strength: Leveraged departmental core compentencies,Strongly defined roles and software interfaces allow maximum collaboration,The Solution,8,What is J2EE?,What is Java 2 Enterprise Edition?,The Java 2 platform, Enterprise Edition reduces the cost and complexity of developing . multi-tier services, resulting in services that can be rapidly deployed and easily enhanced,“,Simplified Guide to the Java 2 Platform, Enterprise Edition, Sun Microsystems, Inc.,9,What is J2EE?,Enabling technology,Standards based application model,A common architecture that provides key common functionality:,Security,Session Management,Scalability,J2EE Provides:,10,What is J2EE?,Applications architecture,Partitioning of application logic,Improves maintainability,Simplifies software upgrades and management,What does multi-tier mean?,11,What is J2EE?,Enables increased aggregate functionality,Reduces component maintenance cost,Separation of workload to improve scalability and reliability,Strong separation prevents vendor lock-in,What does multi-tier mean?,12,Some History,Two tier application (thin client),Easy to upgrade client,Expensive to scale and to add functionality,*,Business Logic,server,client,*,13,Some History,Two tier application (client/server),Strong scalability,Poor upgradability and difficult management,server,client,14,Today,Three tier application,Thin clients make easy upgrades,Centralized application server management is easier to manage,Model allows for horizontal scalability,client,app server,server,15,Today,Three tier application,Thin clients make easy upgrades,Centralized application server management is easier to manage,Model allows for horizontal scalability,client,app server,server,16,Today,17,N-tier application,View application server as a data store,Leverage data abstraction,Today,18,N-Tier Application,19,N-Tier Application,Banner,LDAP,20,N-Tier Application,21,N-Tier Application,22,N-Tier Application,23,N-Tier Complexity,24,Business Logic,25,Business Logic,data,P,R,O,C,E,S,S,O,U,T,P,U,T,I,N,P,U,T,data,26,N-Tier Complexity,27,N-Tier Complexity,28,N-Tier Complexity,29,N-Tier Complexity,30,N-Tier Complexity,31,N-Tier Complexity,32,Servlets,JSP/XML/XSLT,Session,Beans,Entity,Beans,J2EE,33,J2EE,Servlets,JSP/XML/XSLT,Session,Beans,EntityBeans,34,Example: The Kiosk,35,Example: The Kiosk,Servlets,JSP/XML/XSLT,Session,Beans,EntityBeans,article,category,get article,client view,admin view,restore,utility,36,Clones,http:/j2ee.rpi.edu/helpdesk,http:/j2ee.rpi.edu/kiosk,http:/www.va.rpi.edu,http:/www.eng.rpi.edu/frame_news.html,37,The J2EE Framework,Java Technologies,External,Application,