The __________ object provides the filter with its configuration information.
- FilterConfig
- FilterContext
- ResponseConfig
- ServletRequest
The FilterConfig object provides the filter with its configuration information. It is passed to the init() method of the filter during initialization.
In the deployment descriptor, the __________ tag is used to specify which requests are passed through a particular filter.
In the deployment descriptor, the tag is used to specify which requests are passed through a particular filter by associating it with a filter name and a URL pattern.
In a scenario where a filter needs to restrict access based on user roles, which object or method is essential for implementing this?
- checkUserRole()
- getRoleNames()
- getUserPrincipal()
- getUserRoles()
The getUserPrincipal() method is essential for implementing access restrictions based on user roles in a filter. It returns a java.security.Principal object representing the user making the request. The filter can then extract information from this object, such as the user's roles, to make decisions about whether to allow or deny access.
How would a filter log request information without altering the request itself?
- filterConfig.log(request)
- getServletContext().log(request)
- logger.log(request)
- request.log()
To log request information without altering the request itself, the filter should use the getServletContext().log(request) method. This allows the filter to log information through the servlet context, providing a way to record information without modifying the request or response objects.
What is the purpose of the FilterConfig object in Servlet filters?
- To configure the order of filter execution
- To define filter mappings
- To manage filter lifecycle events
- To store configuration parameters for a filter
The FilterConfig object is used to store configuration parameters for a filter, allowing developers to set up filter-specific settings.
Which XML element is used to declare a filter in a web application's deployment descriptor?
- filter
- filter-mapping
- servlet-filter
- web-filter
The element in the web application's deployment descriptor is used to declare a filter, specifying its name and class.
How do you specify the URL patterns to which a filter should apply?
- Using the
- Using the
- Using the
- Using the
URL patterns to which a filter should apply are specified using the element within the element in the web.xml deployment descriptor.
What is a session ID in the context of web applications?
- A Java programming language keyword
- A servlet initialization parameter
- A unique identifier for a user's session
- An HTML form element
A session ID in the context of web applications is a unique identifier assigned to each user's session, enabling the server to distinguish between different user sessions.
How can a filter access initialization parameters set in the web.xml file?
- Initialization parameters cannot be accessed by filters
- Using the FilterConfig object
- Using the HttpServletRequest object
- Using the ServletContext object
A filter can access initialization parameters set in the web.xml file through the FilterConfig object, which is passed to the init() method of the filter. The getInitParameter() method of FilterConfig can be used to retrieve the parameter values.
What is the function of FilterMapping in a web application?
- Defines the filter's initialization parameters
- Indicates the filter's scope
- Maps a filter to a specific servlet or URL pattern
- Specifies the order of filter execution
FilterMapping in a web application is used to map a filter to a specific servlet or URL pattern. It specifies the conditions under which the filter should be invoked, such as when a particular servlet is accessed or when a specific URL pattern is matched.