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.
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.
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.
If a filter needs to perform different actions based on the type of HTTP request, which method or object should it use to determine this?
- doFilter()
- getContentType()
- getRequestDispatcher()
- getRequestType()
The doFilter() method in a filter is responsible for performing different actions based on the type of HTTP request. This method is invoked by the container each time a request/response pair is passed through the chain due to a client request for a resource at the end of the chain.
Filters can be used to implement ________, which is a common requirement in web applications.
- authentication
- authorization
- caching
- logging
Filters can be used to implement authorization, which is a common requirement in web applications.
A filter can alter the header information of a request or response by modifying the __________.
- HeaderFilter
- HeaderInterceptor
- HeaderModifier
- HeaderProcessor
A filter can alter the header information of a request or response by modifying the HeaderModifier.
The sequence of filters applied to a request is determined by the order of __________ in the web.xml file.
- filter-chain
- filter-mapping
- filter-order
- filter-sequence
The sequence of filters applied to a request is determined by the order of the elements in the web.xml file, specifically by the filter-order subelement.
For form submission with file upload, the __________ content type and the _______ method are used.
- GET
- application/x-www-form-urlencoded
- multipart/form-data
- text/plain
For form submission with file upload, the multipart/form-data content type and the POST method are used. This allows for encoding binary data, such as file uploads, in the request.
To pass the request and response to the next entity in the chain, the filter uses the __________ method.
- continueChain()
- doFilter()
- doNext()
- passOn()
To pass the request and response to the next entity in the chain, the filter uses the doFilter() method.
In the deployment descriptor, the __________ tag is used to specify which requests are passed through a particular filter.
- filter-mapping
- filter-name
- servlet-mapping
- url-pattern
In the deployment descriptor, the url-pattern tag is used to specify which requests are passed through a particular filter.
The __________ object provides the filter with its configuration information.
- FilterChain
- FilterConfig
- HttpServletRequest
- ServletContext
The FilterConfig object provides the filter with its configuration information.
How do filters interact with different types of servlets and JSP pages?
- Filters can interact with both servlets and JSP pages in the same way.
- Filters can only interact with JSP pages, not servlets.
- Filters can only interact with servlets, not JSP pages.
- It depends on the filter configuration.
Filters can interact with both servlets and JSP pages in the same way, providing a unified mechanism for processing requests and responses in web applications.