introduction to struts 2.0

Introduction to Struts 2.0

Jenny NiJoey Feng

Winddays WangHewmmi Zhu

Heather Lv

Software School ,Fudan University1

1. What is Struts?2. Why to use framework?3. Struts 2.0 Overview4. Struts 2.0 MVC components5. Request Lifecycle in Struts 26. Struts 2.0 Architecture7. Sample Application8. Why we should use Struts 2.0? 9. Struts 1.x vs Struts 2.0 10. What you need to start using Struts2.0

Contents

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Open Source java framework for creating web applications.

Action Based Framework Create web application using MVC 2

architecture Apache Struts offer two major version

Struts 1.xStruts 2.0

Struts 2 = WebWork + Struts

What is Struts?

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Do we need framework? No and Yes. No. In small applications where you don’t

want the overhead of learning new things. But Yes We have to use framework in real world

application because:-Automation of common tasksConcentrate on higher level concerns.

Why use framework?

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Complete new framework based on webwork framework. Struts 2.0 implements MVC 2 design pattern.

Struts 2.0

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Controller:- Filter Dispatcher:-

First component that start processing that is why this type of MVC is called front controller MVC

Looks at the request and apply the appropriate action. Struts framework handles all of the controller work. Its configured in web.xml

Interceptors:- Can execute code before and after an Action is

executed. They can be configured per action basis. Can be used for data validation, file upload, double

submit guards.

Struts 2.0 MVC Components

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Model:-Implemented by action classFor model you can use any data access

technologies like JDBC,EJB,Hibernate

ViewIts your result part. It can be JSP,JSTL,JSF etc.Presentation part of the MVC

Struts 2.0 MVC Components contd.

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1. User Sends Request2. Filter Dispatcher determines the appropriate action3. Interceptors are applied4. Execution of action5. Output Rendering6. Return of Request7. Display of result to user.

Request Lifecycle in Struts 2.0

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Struts 2.0 Architecture

Struts 2.0 Architecture

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1. Simplified Design2. Simplified Action3. Simplified Testability4. Better tag features5. Annotation introduced6. Easy plug-in7. AJAX Support

Why we should use Struts 2.0?

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How Struts 1.x and Struts 2.0 differ from each other?› Configuration› Action Class› Dependency injection.› Servlet Dependency› Validation› Threading model› Testability› Expression Language

Struts 1.x vs Struts 2.0

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Struts 1Action ActionForm ActionForward struts-config.xml

ActionServlet RequestProcessor

Struts 2ActionAction or POJO’sResultstruts.xmlFilterDispatcherInterceptors

1. Java 5.02. Tomcat 5.x(Servlet api 2.4 and jsp api

2.0)

What you need to start using Struts 2.0?

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Let’s see something real…

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Web, Mail 2000

Web, Mail 2009

Struts Plugins

Simple Example

<html:errors/><html:form action="/SaveMeeting"><table border="0" width="100%"><tr> <th align="right"> Name: </th> <td align="left"> <html:text property="name" size=”50” /> </td></tr><tr> <th align="right"> Date:

Struts 1

</th> <td align="left"> <html:text property="date" size="50"/> </td></tr><tr> <th align="right"> Invitees: </th> <td align="left"> <html:select property="invitees" multiple="true"> <html:options collection="employees" property="value" labelProperty="label"/> </html:select>

</tr><tr> <th align="right"> Description: </th> <td align="left"> <html:textarea property="description" rows="4" cols="50" /> </td></tr><tr> <td align="right"> &nbsp; </td>

...

Only four pages!

<td align="left"> <html:submit property="DO_SUBMIT"> Save </html:submit> </td></tr></table></html:form>

<s:form action="Meeting" validate="true"> <s:token /> <s:textfield label=”Name” name=“name” /> <s:textfield label=”Date" name="date"/> <s:select label=”Invitees” name="invitees" list="employees"/> <s:textarea label=”Description” name="description" rows="4" cols="50" /> <s:submit value=”Save" method="save"/></s:form>

Struts 2

Example Revisited

<s:textfield label="Name" name="name" tooltip="Meeting name" />

<s:datepicker label="Date" name="date"/>

<s:optiontransferselect ... />

<jsp:include page="/ajax/commonInclude.jsp"/>...<s:textarea theme="ajax" label="Description" name="description" rows="4" cols="50" />

But there's more . . .

Brian Kernighan Law of Debugging Difficulty

Debugging is twice as hard as writing the code in the first place. Therefore, if you write

the code as cleverly as possible, you are, by

definition, not smart enough to debug it.

Prevention and Cure

struts.devMode = true

Built-in Testing Support

public class MyActionTest extends StrutsTestCase {

public void testExecute() throws Exception {

assertTrue(true); }}

any.action?debug=console

any.action?profiling=yes

Time to Upgrade?

Tutorials, Guides, and FAQs

Struts 2 Training Course

<action name="editGangster" class="org.apache.struts2.s1.Struts1Action"> <param name="className"> com.mycompany.gangstas.EditGangsterAction </param> <result> gangsterForm.jsp </result></action>

Run Struts 1 Actions as Is

How do I get started?

Where We are Going