In which method of a servlet are most of the resources like threads, database connections, etc., released?
- destroy()
- doGet()
- init()
- service()
The destroy() method is called when a servlet is being removed from service, and it is used to release resources like threads and database connections.
To set multiple values for the same header, use the __________ method in HttpServletResponse.
- addHeader()
- appendHeader()
- setHeader()
- setMultipleValuesHeader()
The addHeader() method in HttpServletResponse is used to add multiple values for the same header, allowing for flexibility in handling headers with multiple values.
A servlet needs to read its own initialization parameters and also share a database connection pool. Which combination of objects should it use?
- getInitParameter() and ServletContext
- getServletConfig() and getServletContext()
- getServletContext() and getInitParameter()
- getServletContext() and getInitParameter()
To read its own initialization parameters, a servlet should use getInitParameter(). To share a database connection pool, it should use the ServletContext, which is accessible via getServletContext().
The __________ method is called to allow the servlet to respond to a request.
- destroy()
- doGet()
- init()
- service()
The service() method is called to allow the servlet to respond to a request. It handles the actual processing of the request.
If a servlet needs to access a shared resource specified in the web application's context parameters, which approach should be used?
- Access the shared resource through the HttpSession object.
- Directly access the shared resource using the File class.
- Use a global variable within the servlet to store the shared resource.
- Utilize the ServletContext to retrieve the shared resource using getInitParameter().
To access a shared resource specified in the web application's context parameters, a servlet should use the ServletContext and the getInitParameter() method. This ensures proper retrieval of the shared resource.
What is session tracking in the context of servlets?
- Handling HTTP requests
- Maintaining user sessions
- Managing servlet lifecycle
- Processing form data
Session tracking in servlets involves maintaining user sessions, allowing the server to recognize and remember users across multiple requests, usually achieved through mechanisms like cookies or URL rewriting.
In a web application with multiple servlets needing a shared resource, where should this resource be initialized?
- In a Servlet class constructor
- In the contextInitialized() method of ServletContextListener
- In the doGet() method of each servlet
- In the init() method of each servlet
For a shared resource across multiple servlets, it's best to initialize it in the contextInitialized() method of a ServletContextListener, ensuring it's available when the application starts.
How does session tracking differ between stateless and stateful protocols?
- Stateful: Lightweight
- Stateful: Stores client state
- Stateless: No memory of previous requests
- Stateless: Uses cookies
Stateless protocols, like HTTP, have no memory of previous requests, while stateful protocols, like HTTPS, store client state, allowing continuity across multiple requests.
What technology is typically used for writing presentation logic in web applications?
- Applet
- JSP
- JavaBean
- Servlet
JavaServer Pages (JSP) is typically used for writing presentation logic in web applications, allowing Java code to be embedded into HTML for dynamic content generation.
How does cookie-based session tracking work in servlets?
- Cookies are not used for session tracking in servlets.
- Cookies are used only for authentication in servlets.
- Cookies are used to store session information on the client side.
- Cookies are used to store session information on the server side.
Cookie-based session tracking in servlets involves storing session information on the client side using cookies. This allows the server to recognize and associate subsequent requests with the same session.