The __________ interface is used to receive events about changes to the servlet context's attribute list.
- ServletAttributeEvent
- ServletContextAttributeEvent
- ServletContextEvent
- ServletEvent
The ServletContextAttributeEvent interface is used to receive events about changes to the servlet context's attribute list.
Can a single class implement multiple listener interfaces in Servlets? If so, what are the considerations?
- No, a class can only implement one listener interface in Servlets.
- No, it depends on the version of the Servlet API.
- Yes, a class can implement multiple listener interfaces.
- Yes, but it is not recommended due to potential conflicts.
Yes, a single class can implement multiple listener interfaces in Servlets. However, it's essential to carefully consider potential conflicts and ensure that the class can handle events from all implemented interfaces.
How does ServletRequestAttributeListener differ from ServletRequestListener in its functionality?
- ServletRequestAttributeListener is triggered only when attributes are added to the request.
- ServletRequestAttributeListener is triggered when attributes are added, removed, or replaced in the request scope.
- ServletRequestListener is triggered only when the request is dispatched.
- ServletRequestListener is triggered when a request is initialized or destroyed.
ServletRequestAttributeListener is specifically designed to listen for changes in request attributes, whereas ServletRequestListener focuses on the initialization and destruction of the request.
Which listener interface allows you to gather statistics about session usage in your web application?
- HttpSessionAttributeListener
- HttpSessionListener
- ServletContextAttributeListener
- ServletRequestAttributeListener
The HttpSessionListener interface allows you to gather statistics about session usage in your web application by tracking session creation and destruction events.
To redirect a client to another resource, the HTTP servlet uses the __________ method.
- forward()
- redirect()
- sendRedirect()
- transfer()
The sendRedirect() method in an HTTP servlet is used to redirect the client to another resource, typically specified by a URL.
What is the purpose of implementing the HttpSessionBindingListener interface?
- To handle session creation
- To listen for changes in the context
- To manage session expiration
- To monitor session attribute changes
Implementing the HttpSessionBindingListener interface allows you to monitor changes to session attributes and take appropriate actions when they occur.
What is the correct order of method calls in the lifecycle of a filter?
- destroy(), init(), doFilter()
- doFilter(), init(), destroy()
- init(), destroy(), doFilter()
- init(), doFilter(), destroy()
The correct order of method calls in the lifecycle of a filter is init(), doFilter(), destroy(). Filters are initialized first, then the doFilter() method is called for each request, and finally, the destroy() method is called when the filter is removed from service.
Which interface must a class implement to act as a filter in a web application?
- Filter
- HttpFilter
- Servlet
- WebFilter
To act as a filter in a web application, a class must implement the Filter interface.
At which point in the request processing are filters applied in a web application?
- After the response is generated by the servlet
- At the end of the servlet lifecycle
- Before the request reaches the servlet
- During servlet initialization
Filters are applied before the request reaches the servlet, allowing for pre-processing of the request or post-processing of the response.
What is the primary purpose of using filters in web applications?
- To handle HTTP requests and responses
- To manage session information
- To perform tasks before or after the request is handled by a servlet
- To store data in the client's browser
The primary purpose of using filters in web applications is to perform tasks before or after the request is handled by a servlet, allowing for common processing tasks to be centralized.
For an e-commerce application that needs to track user session activity and attribute changes, what combination of listeners would be ideal?
- HttpSessionAttributeListener
- HttpSessionListener
- ServletContextListener
- ServletRequestListener
The ideal combination for tracking user session activity and attribute changes in an e-commerce application is to use HttpSessionListener and HttpSessionAttributeListener together.
If an application needs to clean up resources when the application is shut down, which listener should be used?
- HttpSessionListener
- ServletContextAttributeListener
- ServletContextListener
- ServletRequestListener
The ServletContextListener is used to perform actions during the initialization and destruction of the web application, making it suitable for cleaning up resources on application shutdown.