jameszhang
CJSDN高级会员
发贴: 1594
积分: 111
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于 2003-05-13 15:06
To enhance scalability and modularization, J2EE separates enterprise applications into several different tiers: the client presentation tier, the presentation logic tier, and the application logic tier. All three tiers rely on the technology of the Java programming language and the Java TM Virtual Machine
浏览器: The client presentation tier displays information and collects input from the end user. J2EE supports several different types of client presentation technology, including Hypertext Markup Language (HTML) clients, applets, XML documents, and Java standalone clients. In addition, J2EE services support access from clients that do not use Java technology, such as CORBA or Component Object Model (COM) clients.
WEB SERVER: The presentation logic tier accepts user input from HTML, applet, and XML clients, and generates appropriate responses for the user. The developer can implement this tier as Java servlets or as JavaServer Pages (JSP).
EJB SERVER Enterprise JavaBeans (EJ technology is the basis of J2EE. EJB technology provides the scaleable architecture for executing business logic in a distributed computing environment. Entity beans support data persistence, while session beans support server logic processing on behalf of the client. Application logic runs on the server to enable thin clients and reusable business processing.
"First they ignore u, then they laugh at u, then they fight u, then u will win
Mahatma Gandhi"
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