Transcript Struts 2
Introduction to Struts 2.0
Jenny Ni
Joey Feng
Winddays Wang
Hewmmi Zhu
Heather Lv
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Software School ,Fudan University
Contents
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What is Struts?
Why to use framework?
Struts 2.0 Overview
Struts 2.0 MVC components
Request Lifecycle in Struts 2
Struts 2.0 Architecture
Sample Application
Why we should use Struts 2.0?
Struts 1.x vs Struts 2.0
What you need to start using Struts2.0
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What is Struts?
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.x
Struts 2.0
Struts 2 = WebWork + Struts
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Why use framework?
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 tasks
Concentrate on higher level concerns.
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Struts 2.0
Complete new framework based on webwork framework.
Struts 2.0 implements MVC 2 design pattern.
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Struts 2.0 MVC Components
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.
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Struts 2.0 MVC Components contd.
Model: Implemented by action class
For model you can use any data access
technologies like JDBC,EJB,Hibernate
View
Its your result part. It can be JSP,JSTL,JSF etc.
Presentation part of the MVC
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Request Lifecycle in Struts 2.0
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User Sends Request
Filter Dispatcher determines the appropriate action
Interceptors are applied
Execution of action
Output Rendering
Return of Request
Display of result to user.
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Struts 2.0 Architecture
Struts 2.0 Architecture
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Why we should use Struts 2.0?
Simplified Design
2. Simplified Action
3. Simplified Testability
4. Better tag features
5. Annotation introduced
6. Easy plug-in
7. AJAX Support
1.
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Struts 1.x vs Struts 2.0
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
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Struts 1
Action
ActionForm
ActionForward
struts-config.xml
ActionServlet
RequestProcessor
Struts 2
Action
Action or POJO’s
Result
struts.xml
FilterDispatcher
Interceptors
What you need to start using
Struts 2.0?
1.
2.
Java 5.0
Tomcat 5.x(Servlet api 2.4 and jsp api
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
Struts 1
<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:
</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">
</td>
<td align="left">
<html:submit property="DO_SUBMIT">
Save
</html:submit>
</td>
</tr>
</table>
</html:form>
...
Only
four pages!
Struts 2
<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>
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
Run Struts 1 Actions as Is
<action name="editGangster"
class="org.apache.struts2.s1.Struts1Action">
<param name="className">
com.mycompany.gangstas.EditGangsterAction
</param>
<result>
gangsterForm.jsp
</result>
</action>
How do I get started?
Where We are Going