The __________ method is used to initialize the filter with configuration parameters.
- configure(FilterConfig config)
- init(FilterConfig config)
- initialize(FilterConfig config)
- setup(FilterConfig config)
The init(FilterConfig config) method is used to initialize the filter with configuration parameters.
How can a filter be configured to process requests for specific servlets or URL patterns?
- By implementing the processOnly method in the filter.
- By setting the filter-url property in the deployment descriptor.
- By specifying servlet names or URL patterns in the filter's configuration.
- By using the @ProcessFor annotation in the filter code.
A filter can be configured to process requests for specific servlets or URL patterns by specifying servlet names or URL patterns in the filter's configuration in the deployment descriptor.
What is the impact of a filter throwing an unchecked exception during the execution of its doFilter method?
- The container catches the exception and stops processing the request.
- The exception is ignored, and processing continues.
- The filter chain continues to the next filter or servlet.
- The response is sent without further processing.
If a filter throws an unchecked exception, the container catches it. However, the impact is that the processing of the request stops, and the response is not sent.
How can a filter pass control to the next entity in the filter chain?
- chain.continueFiltering(request, response)
- chain.doFilter(request, response)
- filterChain.doFilter(request, response)
- filterChain.passControl(request, response)
To pass control to the next entity in the filter chain, the correct method is chain.doFilter(request, response). It invokes the next filter or the servlet in the chain.
When multiple filters are defined, in what order are they executed?
- Alphabetical order
- Order of declaration in web.xml
- Order specified in filter-mapping
- Random order
Filters are executed in the order of declaration in the web.xml file. The order can be important when one filter's output is used as input to another filter in the chain.
In the context of filter configuration, what is the purpose of the tag in web.xml?
- Associates a filter with a servlet or URL pattern
- Defines filter initialization parameters
- Indicates the filter lifecycle
- Specifies the filter execution order
The tag in web.xml associates a filter with a servlet or URL pattern, specifying where the filter should be applied in the web application.
How does a filter modify the response of a servlet or JSP in the filter chain?
- By modifying the request object
- By modifying the response object
- By replacing the servlet output
- By skipping the filter chain
A filter modifies the response by manipulating the response object in the filter chain. It can modify headers, content, or perform other operations on the response before it reaches the client.
At which stage in the filter lifecycle can you perform actions based on the initialization parameters?
- destroy()
- doFilter()
- filterInit()
- init()
Actions based on initialization parameters can be performed in the doFilter() method, which is part of the filter lifecycle.
What is the first method called when a filter is instantiated by the servlet container?
- destroy()
- doFilter()
- filterInit()
- init()
The filterInit() method is the first method called when a filter is instantiated by the servlet container. It is used for initialization purposes.
What is the correct order of method invocation in a filter's lifecycle?
- destroy(), init(), doFilter()
- doFilter(), init(), destroy()
- init(), destroy(), doFilter()
- init(), doFilter(), destroy()
The correct order of method invocation in a filter's lifecycle is init(), doFilter(), and destroy().
Describe how you would configure a filter to initialize with predefined parameters.
- Implement the init() method in the filter
- Set parameters in the doFilter() method
- Use a configuration file
- Use the
in the deployment descriptor
To configure a filter with predefined parameters, use the element in the deployment descriptor (web.xml) to specify initialization parameters. These parameters can be accessed in the filter using the getInitParameter() method.
How does the load-on-startup element in web.xml affect a servlet's lifecycle?
- It controls the number of instances created for a servlet when handling client requests.
- It decides whether a servlet should be loaded automatically or on demand.
- It determines the order in which servlets are initialized when the application starts.
- It specifies the maximum number of times a servlet can be loaded during the application's lifecycle.
The load-on-startup element in the web.xml file specifies the order in which servlets should be initialized when the application starts. Servlets with lower values are initialized first.