Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
31 Cards in this Set
- Front
- Back
|
What is MVC?
|
Model-View-Controller (MVC) is a design pattern put together to help control change. MVC decouples interface from business logic and data.
|
|
|
What is the Model ?
|
The model contains the core of the application's functionality. The model encapsulates the state of the application. Sometimes the only functionality it contains is state. It knows nothing about the view or controller.
|
|
|
What is the View ?
|
The view provides the presentation of the model. It is the look of the application. The view can access the model getters, but it has no knowledge of the setters. In addition, it knows nothing about the controller. The view should be notified when changes to the model occur.
|
|
|
What is the Controller ?
|
The controller reacts to the user input. It creates and sets the model.
|
|
|
What is Struts ?
|
Struts framework is an open-source framework for developing the web applications in Java EE, based on MVC-2 architecture. It uses and extends the Java Servlet API. Struts is robust architecture and can be used for the development of application of any size. Struts framework makes it much easier to design scalable, reliable Web applications with Java.
|
|
|
What are the MVC components of Struts ?
|
* Model: Components like business logic /business processes and data are the part of model.
* View: HTML, JSP are the view components. * Controller: Action Servlet of Struts is part of Controller components which works as front controller to handle all the requests. |
|
|
What are the core classes of the Struts Framework?
|
* JavaBeans components for managing application state and behavior.
* Event-driven development (via listeners as in traditional GUI development). * Pages that represent MVC-style views; pages reference view roots via the JSF component tree. |
|
|
What is ActionServlet?
|
ActionServlet is a simple servlet which is the backbone of all Struts applications. It is the main Controller component that handles client requests and determines which Action will process each received request. It serves as an Action factory – creating specific Action classes based on user’s request.
|
|
|
What is role of ActionServlet?
|
* Process user requests
* Determine what the user is trying to achieve according to the request * Pull data from the model (if necessary) to be given to the appropriate view, * Select the proper view to respond to the user * Delegates most of this grunt work to Action classes * Is responsible for initialization and clean-up of resources |
|
|
What is the ActionForm?
|
ActionForm is javabean which represents the form inputs containing the request parameters from the View referencing the Action bean.
|
|
|
What are the important methods of ActionForm?
|
The important methods of ActionForm are : validate() & reset().
|
|
|
What is ActionMapping?
|
Action mapping contains all the deployment information for a particular Action bean. This class is to determine where the results of the Action will be sent once its processing is complete.
|
|
|
How is the Action Mapping specified ?
|
We can specify the action mapping in the configuration file called struts-config.xml. Struts framework creates ActionMapping object from <ActionMapping> configuration element of struts-config.xml file
|
|
|
What is role of Action Class?
|
An Action Class performs a role of an adapter between the contents of an incoming HTTP request and the corresponding business logic that should be executed to process this request.
|
|
|
In which method of Action class the business logic is executed ?
|
In the execute() method of Action class the business logic is executed.
|
|
|
What design patterns are used in Struts?
|
* MVC
* Adapter * Service to Worker * Dispatcher View * Composite View (Struts Tiles) * Front Controller * View Helper * Synchronizer Token |
|
|
Can we have more than one struts-config.xml file for a single Struts application?
|
Yes, we can have more than one struts-config.xml for a single Struts application.
|
|
|
What is the difference between session scope and request scope when saving formbean ?
|
when the scope is request,the values of formbean would be available for the current request.
when the scope is session,the values of formbean would be available throughout the session. |
|
|
What are the important tags of struts-config.xml ?
|
* Form bean definitions
* Global forward definitions * Action mappings * Controller configuration * Message resource definition |
|
|
What are the different kinds of actions in Struts?
|
* ForwardAction
* IncludeAction * DispatchAction * LookupDispatchAction * SwitchAction |
|
|
What is DispatchAction?
|
The DispatchAction class is used to group related actions into one class. Using this class, you can have a method for each logical action compared than a single execute method. The DispatchAction dispatches to one of the logical actions represented by the methods. It picks a method to invoke based on an incoming request parameter. The value of the incoming parameter is the name of the method that the DispatchAction will invoke.
|
|
|
What is the use of ForwardAction?
|
The ForwardAction class is useful when you’re trying to integrate Struts into an existing application that uses Servlets to perform business logic functions. You can use this class to take advantage of the Struts controller and its functionality, without having to rewrite the existing Servlets. Use ForwardAction to forward a request to another resource in your application, such as a Servlet that already does business logic processing or even another JSP page. By using this predefined action, you don’t have to write your own Action class. You just have to set up the struts-config file properly to use ForwardAction.
|
|
|
What is IncludeAction?
|
The IncludeAction class is useful when you want to integrate Struts into an application that uses Servlets. Use the IncludeAction class to include another resource in the response to the request being processed.
|
|
|
What is the difference between ForwardAction and IncludeAction?
|
The difference is that you need to use the IncludeAction only if the action is going to be included by another action or jsp. Use ForwardAction to forward a request to another resource in your application, such as a Servlet that already does business logic processing or even another JSP page.
|
|
|
What is LookupDispatchAction?
|
The LookupDispatchAction is a subclass of DispatchAction. It does a reverse lookup on the resource bundle to get the key and then gets the method whose name is associated with the key into the Resource Bundle.
|
|
|
What is the use of LookupDispatchAction?
|
LookupDispatchAction is useful if the method name in the Action is not driven by its name in the front end, but by the Locale independent key into the resource bundle. Since the key is always the same, the LookupDispatchAction shields your application from the side effects of I18N.
|
|
|
What is difference between LookupDispatchAction and DispatchAction?
|
The difference between LookupDispatchAction and DispatchAction is that the actual method that gets called in LookupDispatchAction is based on a lookup of a key value instead of specifying the method name directly.
|
|
|
What is SwitchAction?
|
The SwitchAction class provides a means to switch from a resource in one module to another resource in a different module. SwitchAction is useful only if you have multiple modules in your Struts application. The SwitchAction class can be used as is, without extending.
|
|
|
What is DynaActionForm?
|
A specialized subclass of ActionForm that allows the creation of form beans with dynamic sets of properties (configured in configuration file), without requiring the developer to create a Java class for each type of form bean.
|
|
|
How the exceptions are handled in struts?
|
* Programmatically
* Declaratively within <global-exceptions> tags |
|
|
What is the life cycle of ActionForm?
|
The lifecycle of ActionForm invoked by the RequestProcessor is as follows:
* Retrieve or Create Form Bean associated with Action * "Store" FormBean in appropriate scope (request or session) * Reset the properties of the FormBean * Populate the properties of the FormBean * Validate the properties of the FormBean * Pass FormBean to Action |
