You need to implement a feature in a Spring Boot application where data is streamed from the server to the client as soon as it’s available. How would you implement this feature using reactive programming principles?
- Use WebSocket or Server-Sent Events (SSE) to push data to the client.
- Continuously poll the server for updates using AJAX requests.
- Use traditional REST endpoints to send periodic updates.
- Implement long polling to keep the connection open for updates.
To stream data from the server to the client as soon as it's available in a Spring Boot application using reactive programming principles, you should use WebSocket or Server-Sent Events (SSE). WebSocket and SSE allow for real-time data push to the client, unlike the other options, which involve more traditional request-response mechanisms or polling, which may not be as efficient for real-time updates.
How can you configure a custom method security expression handler in Spring Security?
- By adding @MethodSecurityExpressionHandler annotation to a method.
- By extending the AbstractMethodSecurityExpressionHandler class.
- By implementing the MethodSecurityExpressionHandler interface and registering it in the Spring context.
- By modifying the application.properties file.
To configure a custom method security expression handler, you need to implement the MethodSecurityExpressionHandler interface, create a bean of it, and register it in the Spring context. This allows you to define custom security expressions for method-level security checks.
How does WebFlux differ from the traditional Spring MVC framework in handling HTTP requests?
- Spring MVC uses a reactive programming model.
- Spring MVC uses a servlet-based architecture.
- WebFlux is asynchronous and non-blocking.
- WebFlux is single-threaded and blocking.
WebFlux differs from traditional Spring MVC by being asynchronous and non-blocking. In WebFlux, it handles requests reactively, meaning it can efficiently manage a large number of concurrent connections without blocking threads. On the other hand, traditional Spring MVC relies on a servlet-based architecture, which is typically blocking, making it less suitable for high-concurrency scenarios.
Which feature of Spring Boot simplifies the inclusion of external libraries or modules?
- Spring AOP
- Spring Cloud
- Spring Data
- Spring Initializr
Spring Boot simplifies the inclusion of external libraries or modules through Spring Initializr. Spring Initializr is a web-based tool that generates the project structure with the required dependencies based on your selection. It makes it easy to bootstrap a Spring Boot project with the necessary dependencies without manually managing configuration files.
The @Repository annotation in Spring Boot is particularly useful when working with _____ to interact with the database.
- @EntityManager
- @Service
- @JpaRepository
- @DataSource
The @Repository annotation in Spring Boot is particularly useful when working with @JpaRepository to interact with the database. @JpaRepository is a Spring Data JPA-specific repository interface that provides out-of-the-box CRUD (Create, Read, Update, Delete) operations. While @Service and other options can be used in Spring applications, they are not typically associated with database interaction like @Repository and @JpaRepository.
In Spring Boot, how do you configure the TestRestTemplate to work with a specific profile during integration testing?
- Use @ActiveProfiles annotation
- Use @SpringBootTest with webEnvironment attribute
- Use @ContextConfiguration with locations attribute
- Use @AutoConfigureTestDatabase annotation
To configure the TestRestTemplate to work with a specific profile during integration testing, you can use the @ActiveProfiles annotation. This allows you to specify which application profile to use when running the tests. The other options do not directly configure the TestRestTemplate for a specific profile.
What is the primary purpose of integrating API Gateway with AWS Lambda?
- Expose Lambda functions as HTTP endpoints
- Manage Lambda function deployments
- Scale Lambda functions automatically
- Store data processed by Lambda functions
The primary purpose of integrating API Gateway with AWS Lambda is to expose Lambda functions as HTTP endpoints, allowing clients to invoke the functions over HTTP.
Scenario: During testing, you encounter errors related to AWS Lambda function permissions. How would you troubleshoot and resolve these permission issues effectively?
- Analyze AWS CloudTrail logs
- Check AWS Lambda function configuration
- Contact AWS Support
- Review IAM Policies
Reviewing IAM policies associated with the AWS Lambda function and its execution role can help identify and resolve permission issues effectively.
Can you configure AWS Lambda to process S3 events across multiple AWS regions?
- No, AWS Lambda can only process S3 events within the same region
- No, AWS Lambda does not support processing S3 events across multiple regions
- Yes, by configuring Lambda aliases
- Yes, by configuring event source mappings
AWS Lambda supports configuring event source mappings to process S3 events across multiple AWS regions, enabling cross-region event processing.
Scenario: Your application requires secure authentication for API requests before they reach AWS Lambda. How would you configure API Gateway to handle authentication and authorization?
- Use API Gateway API keys
- Use API Gateway custom authorizers
- Use API Gateway usage plans
- Use AWS IAM roles
By using API Gateway custom authorizers, you can configure secure authentication and authorization for API requests before they reach AWS Lambda, ensuring controlled access to API endpoints.
Scenario: You are building a microservices architecture where multiple AWS Lambda functions handle different API endpoints. How would you design API Gateway to efficiently route incoming requests to the corresponding Lambda functions?
- Use API Gateway custom headers
- Use API Gateway query parameters
- Use API Gateway resource paths and HTTP methods
- Use API Gateway stage variables
By using API Gateway resource paths and HTTP methods, you can efficiently route incoming requests to the corresponding Lambda functions based on the request path and method.
API Gateway allows for the creation of __________, enabling the decoupling of client applications from AWS Lambda implementations.
- API endpoints
- Direct integrations
- Lambda functions
- Webhooks
API Gateway allows for the creation of API endpoints, enabling the decoupling of client applications from AWS Lambda implementations.