In multi-tiered structure, each tier is designed for specific purpose and each tier is isolated from other tier. Mostly multi-tiered applications consist on client tier, middle tier and a data tier. The client tier is a client program that makes requests to the middle tier and the middle tier used different business functions to handle client requests, to process application data and to store required data in database which is in data tier.
Java EE applications used below tiers for its multi-tiered applications development
1- Client Tier
2- Web Tier
3- Business Tier
4- Enterprise Information System (EIS) Tier
Here we shall just focus on the Web Tier and different Java EE technologies used in this tier for presentation of application data. Java EE web tier consists of components which built Webpages based application user interfaces, these components further interact with business tier to show the required information on webpages.
In below table, most used Java EE technologies for Web Tier are being showed which use for development of Java EE based web applications user interfaces.
|Servlets||Servlets is first Java programming language classes used to built HTML pages that dynamically process requests and construct responses.|
|Java Server Faces ( JSF)||JSF is latest Java EE web tier technology. It is a user-interface component framework that allows developers to include different UI components (such as fields, buttons, links) on web pages, UI component data conversion and validation, and to maintain component state.|
|JSF Facelets technology||Facelets is a type of JSF applications that use XHTML pages instead of JSP pages.|
|Expression Language (EL)||Expression Language is a set of standard tags used in JSP and Facelets pages for different purse like interaction with business tier|
|JavaServer Pages (JSP)||JSP is next Web tier technologies after servlet which is a Text-based documents which compiled further into servlets to generate dynamic contents.|
|JSP Standard Tag Library (JSTL)||JSTL is a tag library that encapsulates core functionality common to JSP pages|
|JavaBeans Components||JavaBeans are the Objects which use as temporary data stores for the web pages|