This ppt tells about struts in java. All the methods and brief knowledge of struts. For more info about struts and free projects on it please visit : http://s4al.com/category/study-java/

1. Introduction to
Jakarta Struts
Framework

2. The Evolution of Server Side
Web Ap Developement
 CGI(or ISAPI)
 Servlet
 JSP
 JSP+Bean (Model 1)
 JSP+Bean+XML techs
 Model 2 (MVC)
 Model 2X(MVC with XML techs)

3. What is MVC
 The Model View Controller is a technique used to separate
Business logic/state (the Model) from User Interface (the
View) and program progression/flow (the Control).
 This pattern is very useful when it comes to modern web
development:
– The majority of modern, high usage websites are
dynamically driven.
– People well skilled at presentation (HTML writers) seldom
know how to develop back-end solutions and visa versa.
– Separating business rules from presentation is good no
matter what environment you develop in be it web or
desktop.
資料來源 Craig W. Tataryn ,Introduction to MVC and the Jakarta Struts Framework

5. Benefits of MVC
 Promotes Modularity
 I18n
 Abstraction
 Allows application to be defined in a
flow-chart, use-case or activity
diagram which is more easily
transferred to implementation.
資料來源 Craig W. Tataryn ,Introduction to MVC and the Jakarta Struts Framework

6. The Struts Framework
overview
 Struts is an open source MVC framework developed by the
Apache Jakarta project group.
 Struts allows JSP/Servlet writers the ability to fashion their
web applications using the MVC design pattern.
 By designing your web application using Struts you allow:
– Architect the ability to design using the MVC pattern
– Developer to exploit the Struts framework when building
the app.
– Web designer can learn how to program in MVC.
資料來源 http://jakarta.apache.org/struts/

7. The Struts Framework
overview(2)
 Struts takes much difficult work out of
developing an MVC based web app.
 The Struts framework provides a collection
of canned objects which can facilitate
fundamental aspects of MVC, while allowing
you to extend further as need suites

8. Components of Struts
Framework
 Model
– Business Logic Bean(or session
bean) 、 StateBean(or entity
bean) 、 ActionForm 。
 View
– A Set of Tag library.
– Language Resource File
 Controller
– ActionServlet( controlled by struct-configs.xml)
– ActionClasses
 Utility Classes

9. Components of Struts
Framework(2)
資料來源 http://www-106.ibm.com/developerworks/library/j-struts/?n-j-2151

10. How Struts works
資料來源 http://www-106.ibm.com/developerworks/library/j-struts/?n-j-2151

11. View
 The view in Struts is represented by
JSP pages.
 Minimize the occurance of scriptlets in
your page
–Use the tag-library provided by
Struts to control the presenatational
logic.

12. View:I18n
 The ability to maintain a web app in several
different languages
 Based on the language setup on the client
side, the web app will automatically switch.
 This is achieve in Struts through Java
Resource Bundles
 Instead of having to make a
ResourceBundle class for each language
supported by your web app, resource
bundles can be described as language
resource files

13. Traditional Chinese English
Demo

14. View:I18n(2)
 Language Resource
– FileName Conventions
(ResourceName)_(ISO-LanguageCode)_(ISO-ConturyCode).properties
– Register the Resource Name in web.xml.
 In order for web developers to get at
the string resources we use a special
Struts tag called <bean:message/>

15. View:Example
 Login.jsp
 ApplicationResources_en_US.properti
es
 ApplicationResources_zh_TW.properti
es

16. Model
 ResultBean,hold information needed
to generate the result page.
 FromBean(extend ActionForm ),hold
the data passed by user either by
POST or Query String.
 Business Logic Bean.
 EJB 、 JMS or other components we
impl at business logic layer before.

17. Model:ActionForm
 JSP pages acting as the view for this
LogonForm are automatically updated by
Struts with the current values of the
UserName and Password properties.
 If the user changes the properties via the
JSP page, the LogonForm will automatically
be updated by Struts
 Before an ActionForm object is passed to a
controller for processing, a “validate”
method can be implemented on the form
which allows the form to belay processing
until the user fixes invalid input

18. Model:Example
 LoginForm.java
 tw.edu.nccu.user.TeacherData

19. Control
 The controller is the switch board of MVC.
 It directs the user to the appropriate views by providing the
view with the correct model
 The task of directing users to appropriate views is called
“mapping” in struts.
 The Struts framework provides a base object called
org.apache.struts.action.ActionServlet.
 The ActionServlet class uses a configuration file called
struts-config.xml to read mapping data called action
mappings
 The ActionServlet class reads the incoming URI and tries to
match the URI against a set of action mappings to see if it can
find a controller class which would be willing to handle the
request

20. http://TeacherStudata/login.action
Server configured to pass *.action extensions to
org.apache.struts.action.ActionServlet
via a web.xml configuration file
ActionServlet object inspects the URI and tries to match it
against an ActionMapping located in the struts-config.xml file.
Instance of appropriate Action class is found and it’s perform() method is called
Action object handles the request and returns control to a view based where the user is within
the flow of the application
Controller (2)

21. Control:Example
 tw.edu.nccu.teacherstudata.actions.Lo
ginAction
 Struts-config.xml
 LoginAction.java

22. Problems with Struts
 Does not work on JDK1.4.0
 Steep learning curve.
 Problems on old Application Servers(include
Tomcat3.2.1 、 Weblogic 5.1).
 The only output document is HTML ， it
didn’t support the XSL transform
technology.(Unless we modify the source
code)

23. Model 2X
 Model2X
– Conceived by Julien Mercay and Gilbert
Bouzeid on Feb 1,2002.
– Replace the JSP+TagLib with XML+XSLT
at presentation layer.
– Using XSL Servlet as the Document
Factory.
– Support pipe-line processing while
generating the target document.

26. Resource
 Struts homepage
– http://jakarta.apache.org/struts/
 Sun’s Servlet Specification
– http://java.sun.com/products/servlet/download.ht
ml#specs
 Sun’s JSP Specification
– http://java.sun.com/products/jsp/download.html
 Blue Stone’s Struts Tutorial
– http://developer.bluestone.com/scripts/SaISAPI.
dll/Gallery.class/demos/trailMaps/index.jsp
 My Struts page
– http://java.cc.nccu.edu.tw/struts/