Which method is commonly used for session tracking in servlets?
- doGet()
- doPost()
- getSession()
- init()
The getSession() method is commonly used for session tracking in servlets. It returns the current session associated with the request or creates a new session if one does not exist.
During the servlet lifecycle, which method is called only once and is used for initialization purposes?
- destroy()
- doGet()
- init()
- service()
The init() method is called only once when a servlet is first loaded into memory and is used to perform any necessary initialization tasks.
What is the role of servlet-mapping in the servlet's configuration?
- It configures the servlet's initialization parameters.
- It defines the servlet's behavior in handling HTTP requests.
- It determines the servlet's load-on-startup configuration.
- It specifies the URL pattern to associate with a servlet.
Servlet-mapping in the web.xml file associates a URL pattern with a servlet, specifying which requests should be directed to that servlet for processing. It helps in defining the servlet's mapping to incoming URLs.
What method would you use to set the expiration date of a servlet response as a specific date and time?
- response.setDateHeader("Expires", System.currentTimeMillis() + 86400000);
- response.setExpirationDate("2024-12-31T23:59:59");
- response.setExpirationTime("2024-12-31T23:59:59");
- response.setExpires("2024-12-31T23:59:59");
The response.setDateHeader("Expires", System.currentTimeMillis() + 86400000); method is used to set the expiration date of a servlet response to a specific date and time.
If a servlet needs to perform some action repeatedly every time a request is received, which method is most appropriate for placing such code?
- doGet()
- doPost()
- init()
- service()
The service() method is the most appropriate for placing code that needs to be executed repeatedly every time a request is received. This method is invoked for each incoming request and can handle various HTTP methods like GET, POST, etc.
How does the servlet container pass initialization parameters to the servlet?
- Through XML configuration
- Through environment variables
- Through method parameters
- Through web.xml
The servlet container passes initialization parameters to the servlet through the web.xml configuration file.
When a form is submitted with the enctype as 'multipart/form-data', how should the form data be handled in a servlet?
- This is not supported in servlets
- Use a library like Apache FileUpload
- Use the getInputStream()
- Use the getParameter()
When a form is submitted with the enctype as 'multipart/form-data', the form data should be handled using a library like Apache FileUpload for efficient processing of multipart data in servlets.
Using sendRedirect, the client makes a new _________, resulting in a separate request to the server.
- domain
- request
- response
- session
Using sendRedirect, the client makes a new request, resulting in a separate request to the server.
For secure data transmission, HTTP servlets utilize the _________ protocol.
- HTTPS
- SSL
- SecureHTTP
- TLS
For secure data transmission, HTTP servlets utilize the TLS (Transport Layer Security) protocol.
What is mainly used for creating the view layer in MVC architecture?
- CSS
- HTML
- JSP
- Servlets
JavaServer Pages (JSP) are mainly used for creating the view layer in MVC architecture.
How can you ensure that a response header is set only once in a servlet?
- addHeader()
- sendHeader()
- setHeader()
- writeHeader()
The setHeader() method is used to set a response header in a servlet, and it ensures that the specified header is set only once.
Describe the difference between session cookies and persistent cookies.
- Persistent cookies are often used for user authentication
- Persistent cookies are temporary and expire after the browser is closed
- Session cookies are stored permanently on the client-side
- Session cookies expire after a specified time
Session cookies are temporary and expire when the browser is closed, while persistent cookies are stored on the client-side for a longer duration, typically with an expiration date set by the server.