STRUTS FRAMEWORK

The Jakarta struts project
The Jakarta struts project, an open-source project sponsored by the Apache Software Foundation, is a server side java implementation of the Model-View-Controller (MVC) design pattern.
The struts project was created by Craig McClanahan in May 2000.

What is Struts?

An open source development framework for
building web applications

Based on Model-View-Controller (MVC) design paradigm

Implementation of JSP Model 2 Architecture

Created by Craig McClanahan and donated
to Apache Software Foundation (ASF) in 2000

2nd release candidate of version 1.1 released

Struts Framework Features

Model 2
MVC Implementation
Internationalization(I18N) Support
Rich JSP Tag Libraries
Based on JSP, Servlet, XML, and Java
Supports Java’s Write Once, Run Anywhere Philosophy
Supports different model implementations
(JavaBeans, EJB, etc.)
Supports different presentation
implementations( JSP, XML/XSLT, etc)

Controller Components

ActionServlet – (Framework provided)

Request Processor –(Framework provided)

Action Classes –(You have to build these)

ActionServlet and RequestProcessor
(What Do They Really Do?)

Receive the HttpServletRequest

Automatically populate a JavaBean from the request parameters

Handle Locale and Content Type Issues

Determine which Action to invoke based on URI

Provide extension points
ActionServlet Facts

Extends javax.servlet.http.HttpServlet

Receives all framework requests

Selects proper application module

Delegates request handling to the RequestProcessor instance

One ActionServlet instance per web application

Default implementation provided by
framework (can extend if necessary)

May go away in future versions
The RequestProcessor Class

One instance per application module

Processes all requests for module

Invokes proper Action instance

Default implementation provided by
framework (can extend if necessary)

What’s an Action Class?

Extends org.apache.struts.action.Action

Overrides the execute() method

Acts as a bridge between user-invoked
URI and a business method (Command pattern)

Returns information about which view
should be rendered next

Part of the Controller, not the Model

Struts Includes Pre-built Action Classes

ForwardAction

DispatchAction

LookupDispatchAction

IncludeAction

SwitchAction

TAG LIBRARIES

Struts JSP Tag Libraries

HTML

Bean

Logic

Nested

Tiles

Template