Struts

Agenda

Preface Struts and its components An example The architecture required for

Struts Applications

Preface

Problem we faced when designing JSP: Familiar with HTML and expertise in web

design (the content, font, color, web page layout etc.)

Having Programming knowledge with Java (embedded java code in JSP)

Break down the tasks with Struts

What is Struts

Norwegian word meaning ostrich A Java open source framework

especially used for web application development.

With Struts, developers can following the MVC design pattern to design web application

What is MVC design pattern Input Processing Output Controller Model View

Calculation, database operation, connection with remote systems

Application screen, web pages

Controller in Struts Called ActionServlet Its functions:

- Receive http request from client (Web browser)- Invoke Model part by calling Action objects- Send the JSP file returned by Action objects back to the client

Model component in Struts In Action objects Its functions:

- Carrying out business related processing (by itself or other objects)- Determining the next web page to send to the client

View component in Struts Html and JSP files with Struts

tags embedded Features provided by Struts tags:

- Sophisticated html form handling (validation, error display etc.)- Display localized messages stored in a resource file on web page (message tag)- And many others …

How to get M V C parts work together

A configuration file called struts-config.xml in XML format

Defines Action classes, Java Beans used in the project

Define “virtual” paths to be used in JSP files

An example

In TestWeb1.jsp:…<struts-html:form action=“action1”>…

In struts-config.xml:… < action path=“action1”

type=“JavaBean1”…>… <forward name=“next1"

path="/nextpage1.jsp"/> If changing to use another java

bean as Action class in the future,…

The whole process of a client

request

ActionServletAction objectJavaBean1

JSP / HTML files

nextpage1.jsp

Call “action1”

ActionForward

next1

Clientrequest

find

The architecture required for Struts Applications

Struts Applications

Struts classes / Taglib

Java Application ServerJSP / Servlet engine

Summary

Breakdown web development into MVC parts

Easy to develop and maintain

Questions?