Struts 2

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					Introduction to Struts 2.0
                                                 Jenny Ni
                                               Joey Feng
                                          Winddays Wang
                                             Hewmmi Zhu
                                              Heather Lv




                                                            1
            Software School ,Fudan University
      Contents
1.    What is Struts?
2.    Why to use framework?
3.    Struts 2.0 Overview
4.    Struts 2.0 MVC components
5.    Request Lifecycle in Struts 2
6.    Struts 2.0 Architecture
7.    Sample Application
8.    Why we should use Struts 2.0?
9.    Struts 1.x vs Struts 2.0
10.   What you need to start using Struts2.0

                            Software School ,Fudan University   2
    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

                         Software School ,Fudan University   3
    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.

                            Software School ,Fudan University   4
    Struts 2.0
   Complete new framework based on webwork framework.
   Struts 2.0 implements MVC 2 design pattern.




                                      Software School ,Fudan University   5
    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.


                                   Software School ,Fudan University   6
    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




                                Software School ,Fudan University   7
     Request Lifecycle in Struts 2.0
1.   User Sends Request
2.   Filter Dispatcher determines the appropriate action
3.   Interceptors are applied
4.   Execution of action
5.   Output Rendering
6.   Return of Request
7.   Display of result to user.




                                   Software School ,Fudan University   8
Struts 2.0 Architecture
Struts 2.0 Architecture




               Software School ,Fudan University   10
     Why we should use Struts 2.0?
1. Simplified Design
2. Simplified Action
3. Simplified Testability
4. Better tag features
5. Annotation introduced
6. Easy plug-in
7. AJAX Support



                      Software School ,Fudan University   11
    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

                              Software School ,Fudan University   12
Struts 1                Struts 2
Action                 Action
ActionForm             Action or POJO’s
ActionForward          Result
struts-config.xml      struts.xml
ActionServlet          FilterDispatcher
RequestProcessor       Interceptors
     What you need to start using
     Struts 2.0?
1. Java 5.0
2. Tomcat 5.x(Servlet api 2.4 and jsp api
   2.0)




                       Software School ,Fudan University   14
Let’s see something real…




             Software School ,Fudan University   15
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">
   &nbsp;
 </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

				
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posted:2/1/2012
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