You are developing a Spring Boot application which utilizes reactive programming to handle real-time data. How would you design the application to handle high volumes of concurrent requests efficiently?
- Use a single-threaded event loop to process requests.
- Use a thread pool to handle incoming requests.
- Use the @Async annotation to make controller methods asynchronous.
- Implement reactive backpressure to control the rate of data flow.
When dealing with high volumes of concurrent requests in a reactive Spring Boot application, it's crucial to implement reactive backpressure. Reactive backpressure allows the application to control the rate at which data flows, preventing overloading. The other options may not efficiently handle high concurrency. A single-threaded event loop would be blocking, a thread pool may lead to resource exhaustion, and the @Async annotation doesn't necessarily implement backpressure.
How can @ControllerAdvice be used to customize the response body of a global exception handler?
- By extending @ControllerAdvice from a custom class.
- By annotating the custom class with @ExceptionHandler.
- By configuring the @ControllerAdvice annotation with custom media types.
- By configuring the @ControllerAdvice annotation with @ResponseBodyAdvice classes.
@ControllerAdvice in Spring can be used to handle exceptions globally. To customize the response body, you can use @ControllerAdvice in combination with @ResponseBodyAdvice classes. These classes can customize the response format for specific exception types. The other options may be components used in the process but don't directly address customizing the response body.
In Spring Boot, to map HTTP GET requests to a specific handler method, the _____ annotation is used.
- @GetMapping
- @RequestMapping
- @RequestMethod
- @GetMappingRequestMapping
In Spring Boot, the @GetMapping annotation is used to map HTTP GET requests to a specific handler method. This annotation helps define which method should be invoked when a GET request is made to a particular URL. The other options are not used specifically for mapping GET requests in Spring Boot.
The _____ property in Spring Boot is used to set the TTL (Time-To-Live) for cache entries.
- spring.cache.duration
- spring.cache.expire
- spring.cache.timeout
- spring.cache.ttl
The spring.cache.ttl property in Spring Boot is used to set the Time-To-Live (TTL) for cache entries. This property allows you to specify the maximum amount of time a cache entry should remain valid. When the TTL expires, the cached data is considered stale and is evicted from the cache. It's an important property for cache configuration in Spring Boot.
How can you perform integration testing on security configurations in a Spring Boot application to ensure security constraints are met?
- Use @SpringBootTest with a custom security configuration
- Use @WebMvcTest with a custom security configuration
- Use @AutoConfigureMockMvc with a custom security configuration
- Use @SecurityTest annotation
To perform integration testing on security configurations in Spring Boot, you can use the @SpringBootTest annotation with a custom security configuration. This allows you to test security constraints in the context of the whole application. The other options may not cover all security aspects in the same way.
The _____ annotation in Spring Boot is used to evict specific cache entries to avoid serving stale or outdated data.
- @CacheInvalidate
- @CacheEvict
- @CacheRemove
- @EvictCache
In Spring Boot, the @CacheEvict annotation is used to evict specific cache entries, ensuring that the application does not serve stale or outdated data from the cache. It allows you to specify which cache(s) to evict when a particular method is invoked. The other options are not standard annotations for cache eviction in Spring Boot.
How can you configure different token lifetimes for different OAuth2 clients in a Spring Boot application?
- Configure token lifetimes in the application.properties file, specifying the client ID and associated expiration time.
- Token lifetimes are fixed and cannot be configured differently for different OAuth2 clients in Spring Boot.
- Use a custom TokenEnhancer to modify the token's expiration time based on the client requesting it.
- Use different OAuth2 authorization servers for each client, each with its own token configuration.
To configure different token lifetimes for different OAuth2 clients in a Spring Boot application, you can use a custom TokenEnhancer. This TokenEnhancer can modify the token's expiration time based on the client making the request. By creating a custom TokenEnhancer bean and specifying it in your OAuth2 configuration, you can dynamically adjust token lifetimes based on your specific requirements. This approach provides fine-grained control over token expiration for different clients.
You are assigned to implement Two-Factor Authentication in a Spring Security application. How would you approach this task, considering Spring Security configurations and components?
- Configure Spring Boot to use an external OTP service for two-factor authentication.
- Implement custom authentication filters to handle two-factor authentication.
- Use OAuth2 for authentication instead of two-factor authentication.
- Utilize Spring Security's built-in two-factor authentication support.
To implement Two-Factor Authentication in Spring Security, you would typically need to implement custom authentication filters to handle this process. Spring Security does provide support for two-factor authentication, but it often requires customizations based on specific requirements. OAuth2 is a different authentication mechanism and is not related to Two-Factor Authentication. Configuring Spring Boot to use an external OTP service is a specific approach, not a general method for Two-Factor Authentication.
When using JSR-303 Bean Validation, where can the validation annotations be placed?
- Only on fields within a class.
- Only on method parameters.
- Both on fields within a class and on method parameters.
- Only on class-level annotations.
Validation annotations in JSR-303 can be placed both on fields within a class and on method parameters. This flexibility allows you to validate not only the data fields of a class but also method parameters to ensure that the input meets the specified constraints. The other options are not accurate; you can use validation annotations in both scenarios mentioned.
How can the use of Global Method Security be optimized to secure methods across different layers of a Spring application?
- By annotating each method with @GlobalMethodSecurity
- By configuring AspectJ security expressions
- By setting the global-method-security attribute in XML configuration
- By using role-based annotations like @Secured
Global Method Security can be optimized by configuring AspectJ security expressions. AspectJ expressions allow fine-grained control over method security, enabling security to be applied across different layers of a Spring application based on conditions defined in expressions.