Custom error pages in servlets are configured in the _________ file.
- config.xml
- custom-error.xml
- error-pages.xml
- web.xml
Custom error pages in servlets are configured in the web.xml file. This file allows you to specify error pages for different HTTP status codes, providing custom error handling in your web application.
Servlets can use the _________ interface to log application-level events.
- EventLog
- LogInterface
- Logging
- ServletLog
Servlets can use the Logging interface to log application-level events, providing a standardized way to record various log messages.
The ___________ method is often used to log debugging information in servlets.
- debug()
- debugLog()
- log()
- logDebug()
The log() method is often used to log debugging information in servlets, allowing developers to record messages of various levels, including debugging information.
The use of ___________ in error messages helps in identifying the exact source of an error in servlets.
- error codes
- error details
- stack traces
- timestamps
The use of stack traces in error messages helps in identifying the exact source of an error in servlets, providing detailed information about the error's origin.
A servlet needs to log different levels of messages. Which approach is the most effective?
- Print messages to the console
- Use System.out.println()
- Use a logging framework like Log4j
- Write messages to a file
Using a logging framework like Log4j is the most effective approach for logging in a servlet as it provides flexibility, configurability, and allows logging at different levels.
How can a servlet invalidate a cookie that has been sent to the client?
- By calling response.expireCookie()
- By setting the cookie to null
- By setting the cookie's Max-Age to 0
- By using request.removeCookie()
A servlet can invalidate a cookie by setting its Max-Age attribute to 0, indicating that the cookie has expired, and the client should discard it.
How do you handle an unchecked exception in a servlet?
- Configure error-page in web.xml
- Log the exception using a logging framework
- Throw ServletException
- Use a try-catch block in doGet()
Configuring an error-page in the web.xml file is a common practice to handle unchecked exceptions in a servlet. It allows you to specify an error page that should be displayed in case of an exception.
In a servlet, how can you log an exception along with the stack trace?
- Log using ServletContext.log()
- System.out.println(exception)
- Use a logging framework like Log4j
- response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR)
Using a logging framework like Log4j is the best practice for logging exceptions along with their stack traces in a servlet. This provides more control and flexibility in managing log statements.
What is the best practice for handling sensitive data in servlet log files?
- Disable logging of sensitive data
- Encrypt log files
- Obfuscate sensitive information before logging
- Use a secure logging framework
The best practice for handling sensitive data in servlet log files is to obfuscate the information before logging. This ensures that sensitive details are not exposed in logs, maintaining security and compliance with data protection regulations.
What is the impact of synchronization on servlet performance?
- Degrades performance
- Enhances scalability
- Improves performance
- No impact on performance
Synchronization can degrade servlet performance due to increased contention for locks. It's essential to use synchronization judiciously to prevent performance bottlenecks.