To manage memory efficiently during file upload, using a __________ approach is recommended.
- buffering
- random access
- sequential
- streaming
To manage memory efficiently during file upload, a streaming approach is recommended, allowing the servlet to process the file in chunks rather than loading the entire file into memory.
A servlet is configured to allow only specific file types for upload. What strategies should be implemented to ensure this?
- Rely on the web browser for file type validation
- Use a third-party library for file type validation
- Validate file types on the client side
- Validate file types on the server side
Validating file types on the server side is a more secure approach to ensure that only specific file types are allowed for upload. Relying solely on client-side validation can be bypassed, so it's not recommended. Using a third-party library can also provide robust validation.
Describe a scenario where file download in a servlet might fail and how to address it.
- Incomplete file on the server
- Incorrect file path in the servlet configuration
- Insufficient permissions to read the file
- All of the above
Various factors such as an incomplete file on the server, an incorrect file path in the servlet configuration, or insufficient permissions can lead to file download failure. Addressing all these issues collectively (option 4) provides a comprehensive solution to potential download failures.
In a case where file uploads are taking too long, what are potential causes and solutions?
- Large file size
- Slow network connection
- Insufficient server resources
- All of the above
Potential causes for slow file uploads can include a large file size, a slow network connection, or insufficient server resources. Addressing all these factors collectively (option 4) can help optimize file upload performance.
What is the correct way to set a response header to prevent caching of servlet responses?
- setCacheControl("no-cache")
- setHeader("Cache-Control", "no-store")
- setHeader("Expires", "0")
- setHeader("Pragma", "no-cache")
The correct way to set a response header to prevent caching is by using setHeader("Cache-Control", "no-store"), which instructs the browser not to store the response in its cache.
What is the primary purpose of using HTTPS instead of HTTP in servlets?
- Enhanced Logging
- Faster Performance
- Improved Security
- Simpler Implementation
The primary purpose of using HTTPS in servlets is to provide improved security by encrypting the data transmitted between the client and server, ensuring secure communication.
In servlets, what mechanism is commonly used for user authentication?
- Cookies
- HTTP Basic Authentication
- SSL Certificates
- Session Tracking
User authentication in servlets is commonly achieved using mechanisms like HTTP Basic Authentication, where the server challenges the client for credentials.
What is the role of a servlet filter in security?
- Handle HTTP Requests
- Manage Database Connections
- Manipulate Session Attributes
- Process Security Policies
A servlet filter plays a crucial role in security by processing security policies. It can inspect and manipulate both the request and response to enforce security measures before reaching the servlet.
How can a servlet implement role-based access control?
- By configuring web.xml
- By modifying the servlet container source code
- Using declarative security
- Using programmatic security
Role-based access control in servlets can be implemented using declarative security, where roles are defined in the deployment descriptor (web.xml) and associated with specific resources or operations.
How is session hijacking typically prevented in a servlet-based application?
- By disabling session tracking
- By increasing session timeout
- Using HTTPS
- Using servlet filters
Session hijacking is typically prevented in a servlet-based application by using HTTPS to secure communication between the client and the server, encrypting the session data to prevent unauthorized access.