Answer / rajkumar

ActionServlet acts as a back bone to all the Struts
applications.
Flow:

-->First the request is handled by the either doGet()/doPost
() method of the Action Servlet and it calls the process()
mthod of its own.This method gets the Current Request
Processor associated with the request.

-->Then this request preocessor calls its preocess() method.
(Note:RequestProcessor also one type of Servlet).
This is the actaul place where the request is handled.

-->This method reads the struts-config.xml file and find
outs the Action class by seeing the request url path.
for ex:
incoming request trl path is:/login

struts-config.xml:

<action path="/login" type="Test.LoginClass">
<forward name="Succes" path="/Welcome.jsp"/>
<forward name="failure" path="/Login.jsp"/>
</action>

-->After identifying the Actio class it checks the whether
the request is associtaed with any form bean.This can be
checked by usin the name attribute of athe action element
from the struts-config.xml.

Ex:<form-beans>
<form name="loginForm" type="Test.LoginForm"/>
</form-beans>
<action-mappings>
<action path="/login"type="Test.LoginClass"
name="loginForm">
....
....
</action-mappings>

-->Then it creates the instance of ActionForm and calls the
corresponding getter and setter methods for the incoming
request parameters.Optionally we can validate the request
parameter by calling the validate()method in ActionForm.For
this we need to specify validate="true" and
input="/Login.jsp" in struts-config.xml file.

-->Now the actual request is handled by the Action class by
calling the execute() method.Output of this method
indicates the response of the request.The return type of
this request is ActionMappings ....

Answer / pradeep c

the flow execution of struts.

The browser makes a request to the Struts application that
is processed by ActionServlet (Controller).

ActionServlet (Controller) populates the ActionForm (View)
object with HTML form data and invokes its validate( )
method.

ActionServlet (Controller) executes the Action object
(Controller).

Action (Controller) interfaces with model components and
prepares data for view.

Action (Controller) forwards control to the JSP (View).

JSP (View) uses model data to generate a response to the
browser.

Answer / sandeep garg

ActionServlet acts as a back bone to all the Struts
applications.
Flow:

-->First the request is handled by the either doGet()/doPost
() method of the Action Servlet and it calls the process()
mthod of its own.This method gets the Current Request
Processor associated with the request.

-->Then this request preocessor calls its preocess() method.
(Note:RequestProcessor also one type of Servlet).
This is the actaul place where the request is handled.

-->This method reads the struts-config.xml file and find
outs the Action class by seeing the request url path.
for ex:
incoming request trl path is:/login

struts-config.xml:

<action path="/login" type="Test.LoginClass">
<forward name="Succes" path="/Welcome.jsp"/>
<forward name="failure" path="/Login.jsp"/>
</action>

-->After identifying the Actio class it checks the whether
the request is associtaed with any form bean.This can be
checked by usin the name attribute of athe action element
from the struts-config.xml.

Ex:<form-beans>
<form name="loginForm" type="Test.LoginForm"/>
</form-beans>
<action-mappings>
<action path="/login"type="Test.LoginClass"
name="loginForm">
....
....
</action-mappings>

-->Then it creates the instance of ActionForm and calls the
corresponding getter and setter methods for the incoming
request parameters.Optionally we can validate the request
parameter by calling the validate()method in ActionForm.For
this we need to specify validate="true" and
input="/Login.jsp" in struts-config.xml file.

-->Now the actual request is handled by the Action class by
calling the execute() method.Output of this method
indicates the response of the request.The return type of
this request is ActionMappings ....

Answer / archana dandwate

Actually struts use MVC(model VIew Controller)
Archietecture.

In struts we have to define following things:
1. index.jsp(it takes input from user suppose username)
2.ActionServlet class
3.Action class
4.displayname.jsp(it display username)
---------------------
we need to change 2 file
5.struts-config.xml
6.web.xml
---------------
Lets Start with step one. we will create the view file
named index.jsp


<%@ page language="java" %>
<%@ taglib uri="/WEB-INF/struts-html.tld" prefix="html" %>

<html>
<head>
<title>Sample Struts Application</title>
</head>
<body>
<html:form action="Name" name="nameForm"
type="example.NameForm">
<table width="80%" border="0">
<tr>
<td>Name:</td>
<td><html:text property="name" /></td>
</tr>
<tr>
<td><html:submit /></td>
</tr>
</table>
</html:form>
</body>
</html>
-----------------------------------------

Note:
here we write tag like <html:form> because its struts
specific form tag.
In the Form tags the attributes you can find some
attributes defined in we will go through it.

action : Represents the URL to which this form will be
submitted. This attribute is also used to find the
appropriate ActionMapping in the Struts configuration file,
which we will describe later in this section. The value
used in our example is Name, which will map to an
ActionMapping with a path attribute equal to Name.

name :Identifies the key that the ActionForm will be
referenced by. We use the value NameForm. An ActionForm is
an object that is used by Struts to represent the form data
as a JavaBean. It main purpose is to pass form data between
View and Controller components. We will discuss NameForm
later in this section.
type :Names the fully qualified class name of the form bean
to use in this request. For this example, we use thevalue
example.NameForm, which is an ActionForm object containing
data members matching the inputs of this form.

To use the HTML tags, you must first add a taglib entry in
the application’s web.xml file that references the URI /WEB-
INF/struts-html.tld. This TLD describes all of the tags in
the HTML tag library. The following snippet shows the
<taglib> element that must be added to the web.xml file:

<taglib>
<taglib-uri>/WEB-INF/struts-html.tld</taglib-uri>
<taglib-location>/WEB-INF/struts-html.tld</taglib-location>
</taglib>
--------------------------------------------

The struts-html.tld is placed in the /WEB_INF directory.

Next Step is to create the action form

The ActionForm used in this example contains a single data
member that maps directly to the name input parameter of
the form defined in the index.jsp View. When an
<html:form/> is submitted, the Struts framework populates
the matching data members of the ActionForm with the values
entered into the <html:input/> tags. The Struts framework
does this by using JavaBean reflection. The accessors of
the ActionForm must follow the JavaBean standard naming
convention for example

The NameForm.java file is shown below
NameForm.java

package example;
//import statements
import javax.servlet.http.HttpServletRequest;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionMapping;

public class NameForm extends ActionForm {
private String name = null;
public String getName() {
return (name);
}
public void setName(String name) {
this.name = name;
}
public void reset(ActionMapping mapping,
HttpServletRequest request) {
this.name = null;
}
}
To deploy the NameForm to our Struts application, you need
to compile this class, move it to the /WEB-
INF/classes/example directory, and add the following line
to the <form-beans> section of the /WEB-INF/struts-
config.xml file:

<form-bean name="nameForm" type="example.NameForm"/>

This makes the Struts application aware of the NameForm and
how it should be referenced.

Now we create the out page for the sample application.
Lets name it diplayname.jsp
displayname.jsp

<html>
<head>
<title>Sample Struts Display Name</title>
</head>
<body>
<table width="80%" border="0">
<tr>
<td>Hello <%= request.getAttribute("NAME") %> !!
</td>
</tr>
</table>
</body>
</html>

Now we move to the step two of creating the application's
controller

In a Struts application, two components make up the
Controller. These two components are the
org.apache.struts.action.ActionServlet and the org.apache.
struts.action.Action classes. In most Struts applications,
there is one org. apache.struts.action.ActionServlet
implementation and can have many org.apache.
struts.action.Action implementations.

The org.apache.struts.action.ActionServlet is the
Controller component that handles client requests and
determines which org.apache.struts.action.Action will
process the received request. When assembling simple
applications, such as the one we are building, the default
ActionServlet will satisfy your application needs, and
therefore, you do not need to create a specialized
org.apache.struts.action.ActionServlet implementation.

The second component of a Struts Controller is the
org.apache.struts. action.Action class. As opposed to the
ActionServlet, the Action class must be extended for each
specialized function in your application. This class is
where your application’s specific logic begins.
NameAction.java

package example;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;

public class NameAction extends Action {
public ActionForward execute(ActionMapping mapping,
ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws IOException, ServletException {
String target = new String("success");
if ( form != null ) {
// Use the NameForm to get the request parameters
NameForm nameForm = (NameForm)form;
String name = nameForm.getName();
}
// if no mane supplied Set the target to failure
if ( name == null ) {
target = new String("failure");
}
else {
request.setAttribute("NAME", name);
}
return (mapping.findForward(target));
}
}

Moving to step three, to deploy the NameAction to our
Struts application, we need to compile the NameAction class
and move the class file to /WEB-INF/classes/example
directory, and add the following entry to the <action-
mappings> section of the /WEB-INF/struts-config.xml file:

<action path="/Name" type="example.NameAction"
name="nameForm" input="/index.jsp">
<forward name="success" path="/displayname.jsp"/>
<forward name="failure" path="/index.jsp"/>
</action>


For step four we modify the web.xml file. We have to to
tell the Web application about our ActionServlet. This is
accomplished by adding the following servlet definition to
the /WEB-INF/web.xml file:

<servlet>
<servlet-name>action</servlet-name>
<servlet-class> org.apache.struts.action.ActionServlet
</servlet-class>
<init-param>
<param-name>config</param-name>
<param-value>/WEB-INF/struts-config.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>

Once we have told the container about the ActionServlet, we
need to tell it when the action should be executed. To do
this, we have to add a <servlet-mapping> element to
the /WEB-INF/ web.xml file:

<servlet-mapping>
<servlet-name>action</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
----------------------------------------
important note:
You will notice in the previously listed index.jsp that our
action does not include a .do at the end of the URL. We do
not have to append the .do because it is automatically
appended if we use the <html:form /> tag. If you do not use
the <html:form /> tag, then you will need to append .do to
the action's URL. This mapping tells the Web application
that whenever a request is received with .do appended to
the URL, the servlet named action should service the
request.

Eg:
<html:form action="Name.do" name="nameForm"
type="example.NameForm">

-------------------------------------------------

Answer / rajashree

The Apache Struts development team has announced the
creation of a new sub-project: Struts Flow. "Struts Flow
originated at the struts.sf.net project and has been
formally adopted now as a Struts subproject. Struts Flow is
a port of Apache Cocoon's Control Flow to Struts to allow
complex workflow, like multi-form wizards, to be easily
implemented using continuations-capable Javascript and
eventually Java."

Answer / suresh

Struts is based on MVC architecuture.

1. request comes.

2. corrosponding action class will be searched in the struts.xml

3. mapped form-bean will be populated with data.

4. execute method of mapped action servlet will be executed
and result will be mapped in struts.xml with <forward> tag.

5. mapped jsp/html page with forward will be displayed.

Answer / 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

Answer / ranjeet srivastav

Struts is an open-source framework for building Web
applications based on the MVC pattern. Struts encourages
application architectures based on the MVC pattern and
provides services common to most Web applications.

In a Struts application, you can architect the Model layer
so that the business and data retrieval logic are easy to
reuse. This layer is responsible for running the
application's business logic and getting the relevant data
(for example, running an SQL command or reading a flat
file).

Struts encourages application architectures based on the
Model-View-Controller design paradigm. Struts provides its
own Controller component (the ActionController classes) and
integrates with other technologies to provide the Model and
the View. For the Model (Model classes), Struts can
interact with any standard data access technology,
including Enterprise Java Beans technology, JDBC, and the
Object-Relational Bridge. For the View (ActionForm
classes), Struts works well with the JavaServer Pages (JSP)
environment and other presentation systems. Figure 2
illustrates the logical flow of a Struts-based application.

Answer / sri

The browser makes a request to the Struts application that
is processed by ActionServlet (Controller).

ActionServlet (Controller) populates the ActionForm (View)
object with HTML form data and invokes its validate( )
method.

ActionServlet (Controller) executes the Action object
(Controller).

Action (Controller) interfaces with model components and
prepares data for view.

Action (Controller) forwards control to the JSP (View).

JSP (View) uses model data to generate a response to the
browser.

Answer / gopal g

struts is MVC(Model,View,Controller)Archietecture based
F/W software.

Resourcers OF a Struts Application In 1.0 of Struts :
---------------------------------------------------
we use following resources:

1.jsp(View)
2.Web.xml
3.struts-config.xml
4.FormBean.java (Form Bean)
5.FormAction.java(Action class)
----------------------------------
----------------------------------


Flow OF Struts Application In 1.0 of Struts :
-------------------------------------------

1).End User gives Request to Struts Application,
By Clicking on a button,in JSP(View)of our struts
Application.
2).Then,Request comes to first Web.xml
3).Now from web.xml req goes to Action servlet(Controller
Of Struts Application)
4)Then controller/Front Controller/Req Processer/Dispather
Servlet forwarads req
to Struts configaration file.
5).from there req goes to Action class via Controller
('Model' of Struts App) & it'll execute B.logic there.do so
perations with DB -->return to controller
6).And from Struts configaration file it will goes FormBean
class
via Controller.(In 1.0 of Struts)
7).From FormBean to Response goes to JSP(VIEW).

What is the use of web xml in struts2?

0 Answers  

Explain about token feature in struts?

0 Answers   Tech Mahindra,

what are the disadvantages of MVC architecture

3 Answers   INDUS,

Are actions thread safe?

0 Answers  

How does struts work?

0 Answers  

What is the purpose of @results?

0 Answers  

What is the naming convention for a resource bundle file in struts2?

0 Answers  

why we use struts in our web application , means what was drawbacks of servlet ...pls answer

1 Answers   IBM,

How do you know what to give for the "path " under in struts-config.xml ?

1 Answers  

What is Struts2?

0 Answers  

who will run the execute method in struts?

15 Answers   TCS, Wipro,

Briefly tell the two kinds of form beans.

0 Answers