Struts Basic questions and answers
What are difference between
ActionErrors and ActionMessage?
Ans:ActionMessage:
ActionMessage class encapsulates messages. Messages can be either global or
specific to a particular bean property.Each individual message is described by
an ActionMessage object, which contains a message key (to be looked up in an
appropriate message resources database), and up to four placeholder arguments
used for parametric substitution in the resulting message.
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 they are specific to a
particular bean property (and, therefore, a particular input field on the
corresponding form).
What are the core classes of the
Struts Framework?
Ans:ActionForm, Action, ActionMapping, ActionForward, ActionServlet etc.
Struts Objective Questions And Answers
Struts Objective Questions And Answers
Struts Subjective Questions And Answers
Struts Subjective Questions And Answers
Struts Interview Questions And Answers
Struts Interview Questions And Answers
What is Struts Validator
Framework?
Ans: Struts Framework provides the functionality to validate the form data.
It can be used for validate the data on the users browser as well as on the
server side. Struts Framework emits the java scripts and it can be used validate
the form data on the client browser. Server side validation of form can be
accomplished by sub classing your From Bean with DynaValidatorForm class.
The validate Framework uses two xml files.First one is validation.xml and other
one is validator-rules.xml .The validate frame work was developed by David
Winterfelt as third party .But now the Validator Framework is a part of Jakarta
Commons Project and it can be used with or without Struts. The Validator
framework comes integrated with the Struts Framework and can be used without
doing any extra settings.
Give the Details of XML files used
in Validator Framework?
Ans:The Validator Framework uses two XML configuration files one is
validator-rules.xml and second one validation.xml.The validator-rules.xml
defines the standard validation routines. These routines are reusable and used
in validation.xml to define the form specific validations. The
validation.xml defines the validations applied to a form bean.
What are Tag Libraries provided
with Struts?
Ans: Struts Frameworks provides a number of tag libraries that helps to
create view components in easy way.
These tag libraries are:
a) Bean Tags: The bean Tags are used to access the beans and their
properties.
b)HTML Tags: HTML Tags provides tags for creating the view components like
forms, buttons, etc.
c) Logic Tags: Logic Tags provides presentation logics that eliminate the
need for scriptlets.
d)Nested Tags: Nested Tags helps to work with the nested context.
What are the components of Struts?
Ans: Struts is based on the MVC design pattern. Struts components can be
categories into Model, View and Controller.
Model: Components like business logic / business processes and data are the
part of Model. Java Bean is used .
View: JSP, HTML etc. are part of View
Controller: Controller is backbone of any struts application. ActionServlet
of struts is part of Controller components which works as front controller to
handle all the requests.
What is Struts actions and action
mappings?
Ans:A Struts action is an instance of a subclass of an Action class, which
implements a portion of a Web application and whose perform or execute method
returns a forward. An action can perform tasks such as validating a user name
and password.
An action mapping is a configuration file entry that is associates an action
name with an action. An action mapping can contain a reference to a form bean
that the action can use, and can additionally define a list of local forwards
that is visible only to this action.
What is MVC Architecture?
Ans:MVC stands for Model ViewController. MVC pattern is a
collaboration of three components model, view and controller.Model is backend
database or java bean.View is output html or jsp.Controller is logic that is
servlet.MVC pattern is a sequence of action interactions starting with view,then
controller and then to model based on the data persistence. MVC is an approach
for developing interactive application i.e. it results in events through user
interactions.Model is responsible for holding the application state, View is for
displaying the current model and controller handles the event..
How to get data from the velocity
page in a action class?
Ans:We can get the values in the action classes by using
data.getParameter(”variable name defined in the velocity page”)
How you will enable front-end
validation based on the xml in validation.xml?
Ans: The tag to allow front-end validation based on the xml in
validation.xml. For example the code: generates the client side javascript for
the form \”logonForm\” as defined in the validation.xml file. The when added in
the jsp file generates the client site validation script.
What is ActionForm?
Ans:An ActionForm is a JavaBean that extends
org.apache.struts.action.ActionForm. ActionForm maintains the session state
for web application and the ActionForm object is automatically populated
on the server side with data entered from a form on the client side.
What is Action class?
Ans: The Action class is part of the Model and is a wrapper around the
business logic. The purpose of Action Class is to translate the
HttpServletRequest to the business logic. To use the Action, we need to
subclass and overwrite the execute() method. In the Action class all the
database/business processing are done. It is advisable to perform all the
database related stuffs in the Action Class. The ActionServlet passes the
parameterized class to ActionForm using the execute() method. The return type of
the execute method is ActionForward which is used by the Struts Framework to
forward the request to the file as per the value of the returned ActionForward
object.
What is ActionServlet?
Ans:The class org.apache.struts.action.ActionServlet is the called
the ActionServlet. In the the Jakarta Struts Framework this class plays
the role of controller. All the requests to the server goes through the
controller. Controller is responsible for handling all the requests.
How you will make available any Message Resources Definitions file to the Struts
Framework Environment?
Ans: Message Resources Definitions file are simple .properties files
and these files contains the messages that can be used in the struts project.
Message Resources Definitions files can be added to the struts-config.xml file
through tag. The message stored into message resources file is in key/value
pairs.
Struts
Basic questions and answers
