What is Struts Flow?

Answer Posted / prabhakar

Struts Flow
===========


1) When application server gets started,container loads the
web.xml

2) When first the request is made from a JSP/HTML/XSLT to
the server with a particular URI(/something.do) the control
first reaches Web.xml file.

3) It checks the mapping for /something.do in web.xml and
finds the ActionServlet and loads ActionServlet.
......
<servlet-name>action</servlet-name>
<servlet-class>org.apache.struts.action.ActionServlet</servlet-class>
.....

<servlet-mapping>
<servlet-name>action</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>

4) As part of loading ActionServlet calls the init() as
every other servlet does.
(Note: ActionServlet extends HttpServlet only)
......................
<init-param>
<param-name>config</param-name>
<param-value>/WEB-INF/struts-config.xml</param-value>
</init-param>
........................

5) In init() it takes the init-parameters as
struts-config.xml and loads the xml file.

6) Then the ActionServlet calls the process() method of
RequestProcessor class.

7) process() method checks for the appropriate action in the
action mapping for current request and maps the URI to the
action in the struts-config.xml.

8) Then it creates an object to ActionForm associated to
that action.

9) It then calls the setters and reset() methods in the form
bean(Which extends ActionForm) corresponds to the mapped action.

10) If the action tag in struts-config.xml contains validate
"true" then the validate method is called.

11) if any validation errors it return to view component
(any jsp XSLT) which is specified as an attribute of input
"/error.jsp"

12) if there are no validation errors ,it then search for
execute method in the action class and executes it.

13) execute method performs the bussinesslogic which you
provide and returns with an ActionForward key.

14) Now the returned key is searched in the mapped action
which is specified as forward tag.

15) It looks for the appropriate view component and performs
the getters on that action form corresponding to this view
component and loads the view page in the browser.


- Prabhakar

Is This Answer Correct ?    7 Yes 1 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

Give an example where struts tiles may be used?

736


Explain about how requests from the client are sent?

672


What are the Core classes of Struts Framework?

759


Explain about tiles?

773


What is the purpose of @requiredstringvalidator?

724


What is defeult result type?

823


What is the difference between validation.xml and validator-rules.xml files in struts validation framework?

789


Explain the complete struts validator framework.

735


Where can I get a copy of struts?

700


Which class is the Front Controller in Struts2?

712


Explain about logic match tag?

773


Explain about token feature in struts?

729


Why do we need mapdispatchtoprops?

648


What do you mean by struts.dev mode?

698


What configuration changes are required to use resource files in Struts?

766