How would you ensure a filter only processes requests for a specific servlet?
- Check the servlet name in the configuration
- Set a specific attribute in the request
- Use if conditions in the doFilter() method
- Use the url-pattern in the filter mapping
To ensure a filter processes requests for a specific servlet, configure the filter mapping in the deployment descriptor (web.xml) using the url-pattern element with the appropriate servlet mapping.
What is the primary purpose of a filter chain in a servlet environment?
- To establish a secure connection
- To execute servlets sequentially
- To handle exceptions in a servlet
- To perform multiple filters on a request and response
The primary purpose of a filter chain is to allow multiple filters to be applied to a request and response in a sequential order, enabling the execution of various processing tasks.
How does a filter pass the request and response to the next entity in the filter chain?
- Automatically passed by the servlet container
- By directly calling the next filter
- By setting a flag in the request
- Using the chain.doFilter() method
A filter passes the request and response to the next entity in the filter chain using the chain.doFilter() method, which allows the request and response to move to the next filter or servlet in the chain.
Which method is used to initialize a filter in the filter chain?
- init()
- initFilter()
- initialize()
- initializeFilter()
The init() method is used to initialize a filter in the filter chain. This method is called by the servlet container when the filter is first created.
What is the first method called in the lifecycle of a servlet?
- destroy()
- doGet()
- init()
- service()
The init() method is called when a servlet is first loaded into memory and is used for initialization purposes.
How can filters modify the request and response objects in a filter chain?
- Modify only the request object
- Modify the objects directly
- Use the doFilter() method
- Use the init() method
Filters can modify the request and response objects by using the doFilter() method in the filter chain.
Which method is responsible for cleaning up resources held by a filter in the filter chain?
- cleanUp()
- cleanupResources()
- destroy()
- releaseResources()
The destroy() method is responsible for cleaning up resources held by a filter in the filter chain.
How can a filter chain be used to implement security checks in a web application?
- Bypass the filter chain for security checks
- Implement security logic in each filter
- Include multiple filter instances in the chain
- Use only a single filter for all security checks
A filter chain can be used to implement security checks by including multiple filter instances, each responsible for a specific security aspect, and processing them in the order they are configured.
What happens if a filter in the filter chain does not call the doFilter() method?
- An exception is thrown
- The filter chain continues processing without the filter
- The request processing stops
- The response is sent to the client directly
If a filter does not call the doFilter() method, the request processing stops, and the subsequent filters in the chain and the servlet are not invoked.
How does filter ordering affect the processing of requests and responses in a servlet application?
- Filter ordering has no impact on processing
- Filters are always processed in a random order
- Filters are processed in the order they are declared
- Filters are processed in the reverse order they are declared
Filter ordering affects the processing of requests and responses in a servlet application. They are processed in the reverse order they are declared in the deployment descriptor, affecting the sequence of their execution.