How can you avoid concurrency issues in a servlet without using synchronization?
- Implement single-threaded model
- Optimize database queries
- Use synchronized blocks
- Use volatile variables
Concurrency issues can be avoided by implementing a single-threaded model where a servlet processes one request at a time, eliminating the need for synchronization.
In what scenarios is it safe to have instance variables in a servlet?
- Always safe
- Never safe
- When shared across sessions
- When thread safety is guaranteed
Instance variables in a servlet are safe when they are shared across sessions and thread safety is guaranteed, ensuring that multiple requests can access them concurrently without issues.
The __________ pattern is often used to manage shared resources in a thread-safe manner in servlets.
- Decorator
- Factory
- Observer
- Singleton
The Singleton pattern is often used to manage shared resources in a thread-safe manner in servlets, ensuring that only one instance of the resource is created.
Servlets can be made thread-safe by making shared resources __________.
- abstract
- final
- synchronized
- volatile
Servlets can be made thread-safe by making shared resources synchronized, which ensures that only one thread can access the resource at a time.
The _________ method should be used carefully in servlets due to potential thread safety issues.
- destroy()
- doGet()
- init()
- service()
The service() method should be used carefully in servlets due to potential thread safety issues. It handles requests and might result in multiple threads accessing the servlet concurrently, requiring careful consideration for thread safety.
A thread-safe servlet ensures that shared data is accessed in a _________ manner.
- parallel
- random
- sequential
- synchronized
A thread-safe servlet ensures that shared data is accessed in a synchronized manner. This prevents multiple threads from accessing the shared data simultaneously, reducing the risk of data corruption and ensuring proper thread safety.
In HTTP servlets, the _________ method is used to send error responses back to the client.
- doError()
- errorResponse()
- handleError()
- sendError()
The sendError() method in HTTP servlets is used to send error responses back to the client, providing information about the encountered error.
In a highly concurrent web application, how would you design a servlet to handle database connections securely and efficiently?
- Open a new database connection for each request.
- Store database connections as static variables.
- Use a connection pool to manage database connections.
- Use synchronized methods for database operations.
Using a connection pool is a best practice in highly concurrent applications as it efficiently manages and shares database connections, reducing the overhead of opening and closing connections for each request.
If a servlet manipulates a shared data structure, what must be done to ensure it operates correctly in a multithreaded environment?
- Avoid multithreading in servlets.
- Synchronize access to the shared data structure.
- Use multiple instances of the servlet.
- Use volatile keyword for the shared data structure.
Synchronizing access to the shared data structure is crucial in a multithreaded environment to prevent data corruption and ensure consistency. The synchronized keyword ensures that only one thread can access the shared data structure at a time.
To handle a POST request, the HttpServlet class uses the _________ method.
- doGet()
- doPost()
- handlePost()
- servicePost()
To handle a POST request, the HttpServlet class uses the doPost() method.