Latest Answer: Hi to allAs Madhav specified (Struts
follows MVC architecture and has many design patterns which it uses inside(ex
Frontcontroller,Value Objects). )what are the other design patterns which it
uses inside and can it be brief ...
Read Answers (10) | Asked by : raghavendhark
Latest Answer: Static methods are BAD BAD thing, should b
always prohibited. They bind u to a concrete class. Remeber the first good
practice of OOP, always program to interfaces rather than classes. Use a
factory with singelton rather than a static method. However ...
Read Answers (4) | Asked by : samidurai.v
Latest Answer: Apache struts and Jakarta Struts are one or
the same thingbyee ...
Read Answers (4) | Asked by : Developer
I have linux OS.I installed Tomcat 4. in Linux.Now, i have to deploy My web
application into that using WAR file.Please tell me steps....and also steps for
the creating the WAR file too.
Read Answers (4) | Asked by : Rahul Bandgar
Wats meant by
struts?how to use struts in IBM websphere appli. ?and how to managed with
struts?(plz answer simply just an intro. don\'t go very deep)
Read Answers (3) | Asked by : karthik
Latest Answer: Servlet Config parameters are set for the
servlet initialization, these information is necessary for the servlet startup, eg.: Database connectivity, other xml files. etc.Servlet Context
are used by the servlets to interact with the SERVER, servlet can ...
Read Answers (6) | Asked by : p.vinodReddy
Latest Answer: Good Explanation !! keep it up !! ...
Read Answers (4) | Asked by : Sonu
Latest Answer: The findByPrimaryKey() method works like the
read() method, except that the findByPrimaryKey() method retrieves a single
TxObject directly from the database using a primary key without going through a
TxCursor. The primary key can be any primary key. ...
Read Answers (1) | Asked by : Hari Krishna P
please post the
answer
Latest Answer: Struts controller uses the command design
pattern and the action classes use the adapter design pattern. The process()
method of the RequestProcessor uses the template method design pattern. Struts
also implement the following J2EE design patterns. ...
Read Answers (26) | Asked by : sudhakar
Latest Answer: MVC1A Model 1 application
control is decentralized, because the current page being displayed determines
the next page to display. In addition, each JSP page or servlet processes its
own inputs (parameters from GET or POST). In some Model 1 architectures, ...
Read Answers (20) | Asked by : Chennaiah
pl any one answer
Latest Answer:
To pass the values from dyna form to entity bean, we should follow
some design patterns.from action to business delegate(java
bean)----->sesstion bean1----->>sesstion ...
Read Answers (3) | Asked by : vishnu
need answer
Latest Answer: Struts implements MVC design so that we can
divide the web application in to view, data access/modify and controller
layers. JSPs and HTMLs are come into view, when a user enters data
into form and submits a request, it goes to Action servlet, in which ...
Read Answers (4) | Asked by : saraswati
Latest Answer: When we want the action form to persist the
values across the request, we set the action form to session scope.For ex. When
i submit the registration form with some errors in the form, then in the
Action form fields validation throws errors in the JSP ...
Read Answers (13) | Asked by : kanthakumar
Yes, other than
JSP we can use Swing, JSF, Cocoon etc as a front end for our struts
application. Here is a link to the article for using struts with swing as front
end
Latest Answer: But how can I use the Swing, or any other
technology for front end view? ...
Read Answers (10) | Asked by : Amit Mudgal
No, These
features are turned off by default. One has to enable the plugins by properly
inserting entries in Struts-config.xml
Latest Answer: Ya, All about sturts is framework. It will
provide some custom tag libraries. Also struts give one validator frame work
for both client and server validation. We can make use of this validator
framework so that it will reduce the effort of devloper to ...
Read Answers (4) | Asked by : Amit Mudgal
Latest Answer: no it is not possible ...
Read Answers (1) | Asked by : shailendra
Is there any way
to put my custom name to LIB folder which i am going to place in WEB-INF folder
of struts application?
please answer
this question
Read Answers (5) | Asked by : gskumar
Latest Answer: Due its a bad practice to instantiate form
beans in your code as their life
cycle is managed by STRUTS
in a kinda IOC style ...
Answered by asreeni
on 2005-04-08 03:24:40: The core of the Struts framework is a flexible control
layer based on standard technologies like Java Servlets, JavaBeans, ResourceBundles,
and XML, as well
Latest Answer: I worked with struts it completely MVC base. I
used SHINE pattern. It is a MVC base too. Actually it is an open source project to implement J2EE application.
...
Latest Answer: Struts flow After developing the struts
application after deploying it is the server & when you started the server
then following things will happened Container initializes the web.xml When
container reading the data from web.xml container checks ...
Latest Answer: ActionForm is static form bean and
DynaActionForm is dynamic formbean. If we want to use DynaActionForm no need
write formbean we need to write all the jsp fields in Sturts-config.xmlÂ
...
Latest Answer: Struts Framework developed using MVC design
pattern. It will represent Controller and view layer.In view layer it will use
taylibraries and jsp, jstl tags, htmlIn controller layer ActionServlet act as a
controller layer ...
1. Action
Servlet2. Action Classes3. Action Form4. Validator Framework5. Message
Resources6. Struts Configuration XML Files7. View components like JSP
Latest Answer: 1. Action Servlet2. Action Classes3. Action
Form4. Validator Framework5. Message Resources6. Struts Configuration XML
Files7. View components like JSP8. Struts-tag laibraries ...
Latest Answer: Please give me code for this :In single JSP
how we maintain only one Basically Dispatch action is used when you have
multiple submit buttons in a single form.The Dispatch action is a class which
extends the Struts DispatchAction , and encapsulates all ...
Latest Answer: There are only five struts tag libraries1)Bean
tag lib2)Html tag lib3)logic tag lib4)nested tag lib5)Template tag libothers
are JSTL tag libraries(ex: c.tld,sql.tld,fmt.tld) ...
Latest Answer: In tiles-def.xml we can define the definations
which specifies the different components to plugin to generate
output.resourcebundle.properties maintains messages used in the struts
project.validation.xml maintains the validation code for validating form ...
Latest Answer: The new features added to Struts 1.1 are 1.
RequestProcessor class 2. Method perform() replaced by execute() in Struts base
Action Class3. Changes to web.xml and struts-config.xml4.Declarative
exception handling5.Dynamic ActionForms6.Plug-ins7.Multiple ...
Latest Answer: Yes, we use Service locator design
pattern We can call from Action Calss through JNDI to home
object. then call remote
object from home object ...
Latest Answer: hi,to handle the errors:in struts project to handle the error objet
by using ActionError object and to handle the errors by using ActionErrors
object.for supposeActionError ae1=new
ActionError("err.one");ActionError ae2=new
ActionError("err.two");Action ...
Latest Answer: The core class of struts framework is 1)
ActionServlet2) Action3) ActionForward4) ActionMapping5) ActionErrors6)
RequestProcessor7) ActionForm ...
Latest Answer: Action Class acts as a controller b/n user
data and business logic.It is having execte() method using this we are calling
business logic.Execute method syntax :-public ActionForward execute(ActionMapping
am,ActionForm fm,HttpservletRequest rq,HttpServletResponse ...
Latest Answer: Tokens are used to prevent multi click problem
in struts. In Action class method at the begining of the code, need to call the
saveToken() that generates an unique identifier for the "request url"
and stotes it in the session and also in the ...
Latest Answer: These are the tags we can define ,,,,,
...
Latest Answer: Action
Errors(org.apache.struts.action.ActionErrors): A class that encapsulates the
error messages being reported by the validate() method of an ActionForm.
Validation errors are either global to the entire ActionForm bean they are
associated with, or ...
Q: how to perform data validation in a
struts application?
-to transfer complete and proper input to
the model layer and there by to the database, server side validations are
performed on form data.
-server side validation can be implemented
in two ways.
1.programmatical 2.declarative
Q: what is programmatical validation and
how to implement it?
-if validation code is explicitly developed
by the struts application developer with in the validate method of the
form-bean, it is known as programmatical validation.
-steps to perform programmatical
validation:
1. in the form bean override validate
method and implement validation code.
2. enable the validation check by making an
entry in struts-config.xml
<action ………… validate=”true”
input=”/some.jsp”/>
-if validation fails, control switched to
some.jsp.
3.developing and configuring the resource
bundle with error keys and corresponding error messages.
4.using <html:errors /> in the input
page to display error messages.
Ex: public class LoginForm extends
ActionForm{
private string username;
private String password;
setters&getters
public ActionErrors validate(ActionMapping
am,HttpServletRequest req) {
ActionErrors ae=new ActionErrors();
If(username.equals(“ “)||username==null)
ae.add(“username”, new
ActionError(“error.name.required”));
if(password.equals(“ “)||password==null)
ae.add(“password”, new
ActionError(“error.password.required”));
return ae;
}
}
-if ActionErrors returned by validate
method is empty or null then RequestProcessor understands that the form data is
valid. If not RequestProcessor considers the form data is valid.
Q: what is ActionError?
-ActionError is struts library class whose
instance represents validation failure of one data field.
-ActionError instance takes resource bundle
key from its constructor.
-validate method of form bean creates
ActionError instance for each validation failure of a form field and adds to
ActionErrors object.
Q: what is ActionErrors ?
-it is a collection class from struts
library.
-this object holds the references to
ActionError objects.
-struts framework known about validation
failure depending upon this object.
-if ActionErrors returned by the validation
method empty or null then RequestProcessor understands that the form data is valid. If not RequestProcessor
considers the form data is not valid.
Q: what is declarative validation? How to
implement it?
-instead of struts developer writing
validation code explicitly using framework given validation functionality in a
struts application by specifying the validation requirements in a special xml
file is known as declarative validation.
-steps to implement declarative validation:
1.developing validation.xml file which
indicates to the framework our validation needs.
2.framework provided validator-rules.xml
and our own developed validation.xml have to be placed in WEB-INF.
3.configure ValidatorPlugIn in
struts-config.xml file so that it loads the xml file definitions into struts
environment.
4.develop the form bean class that extends
validatorForm.
<plug-in className=”org.apache.struts.validator.ValidatorPlugIn”>
<set-property property=”pathnames”
value=”/WEB-INF/validation.xml,/WEB-INF/validator-rules.xml”/>
</plug-in>
Q: what is validator-rules.xml?
-validator-rules.xml is given by struts
framework.
-this file is a collection of
validators(tags).
-each validator tag specifies a logical
name to built-in validation method. It also specifies the error key that is
returned by the java validation method.
-in this file, for each validation java
method a javascript function also specified which is useful for client side
validations.
-this file specifies all the possible
built-in validation routines given by struts framework.
Q: what is validation.xml files?
-it specifies to the framework which
routines are required for which form beans of the application
-<form-validation>
<formset>
<form name=”loginform”>
<field property=”username”
depends=”required”>
<arg0 key=”username”/>
</field>
<field property=”password”
depends=”required,minlength”>
<arg0 key=”password”/>
<arg1 key=”4” resource=”false” />
<var>
<var-name>minlength</var-name>
<var-value>4</var-value>
</var>
</field>
</form>
</formset>
</form-validation>
Q: what is mean by depends=”mask”?
-mask is the predefined validator rule
which allows the programmer to add user defined logic in the form of regular expression.
-the error message related to this rule can
be defined by the programmer manually in properties file.
Ex: <var>
<var-name> mask</var-name>
<var-value>[a-z A-Z]
*$</var-value>
</var>
<field property=”pwd”
depends=”required,mask”>
<arg0 key=”my.pass”/>
<msg name=”mask” key=”my.mask.msg”/>
-<msg> tag is used for defining
message related to the mask rules.
Q: what are the different types of built-in
actions in struts?
1.ForwardAction
2.IncludeAction
3.DispatchAction
4.LookupDispatchAction
5.MappingDispatchAction
6.LocaleAction
7.SwitchAction
-the above all the classes are from
org.apache.struts.actions package.
Q: what is the difference between Action
and DispatchAction?
-in Action class, we develop our own
application specific application logic in execute() method only.
-in DispatchAction, we develop our own
application specific application logic in our own defined methods which prototype
is same as execute method.
-in DispatchAction, don’t override the
execute() method .
-if we want to perform multiple
functionalities to be performed by the action required from the same form based
on the given parameter value.
Ex:
public class MyAction extends DispatchAction{
Public ActionForward sub/add(ActionMapping
am,ActionForm af,HttpServletRequest req,HttpServletResponse res) {
----- --
}
}
-configure the above action class with a
special attribute parameter in addition to other attributes. This attribute
value must match the request parameter name from the web form.
<action path=”/myaction” type=”MyAction”
parameter=”submit”>
Q: how to enable client side validation
provided by validator framework?
-in the input page make use of javascript
tag of html library
<html:javascript formName=”loginform” />
-once the above tag is executed, a
javascript function with name validateLoginform() is generated with client side
validation code appended to the html page generated by input jsp.
-in the input page, make use of “onSubmit”
attribute of form tag of html library.
<html:form ….. onsubmit=return
validateLoginform(this)”>
-when ever end-user clicked on the submit
button of the html form, “onSubmit” event is fired and the specified javascript
function is called in which, client side validation code is implemented. This
method returns false if validation is failed . then the form is not submitted
to the server.
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