In a Spring Boot application, to handle exceptions globally, you can use the _____ annotation on a class.
- @ControllerAdvice
- @ExceptionHandler
- @GlobalExceptionHandler
- @RestController
In a Spring Boot application, to handle exceptions globally, you can use the @ControllerAdvice annotation on a class. This annotation allows you to define global exception handling methods that can be applied across multiple controllers in your application. It's a powerful mechanism for centralizing exception handling logic.
What is the primary use of the @PreAuthorize annotation in Spring Security?
- To execute a method before a security check
- To post-authorize access to a method
- To restrict access to a method based on a condition before it's executed
- To specify the method's execution time
The primary use of @PreAuthorize is to restrict access to a method based on a condition before it's executed. You can define an expression in this annotation to control who can access the method.
In Spring Boot, which file is primarily used by the auto-configuration system to list all the candidate configurations?
- application.properties
- application.yml
- bootstrap.properties
- spring-config.xml
In Spring Boot, the auto-configuration system primarily uses the application.yml (or application.properties) file to list all the candidate configurations. This file allows developers to specify configuration properties and settings for their Spring Boot application, including those related to auto-configuration. It's a key component in customizing the behavior of Spring Boot applications.
To implement client-side load balancing in a Spring Cloud application, the _____ component can be used.
- Eureka
- Feign
- Hystrix
- Ribbon
To implement client-side load balancing in a Spring Cloud application, the Ribbon component can be used. Ribbon is a client-side load balancer provided by Netflix, which works seamlessly with Spring Cloud. It allows you to distribute incoming requests to multiple instances of a service, enhancing fault tolerance and improving the overall performance of your microservices architecture. Ribbon integrates with Eureka for service discovery, making it a valuable component for building resilient microservices.
You are tasked with implementing auditing features in a Spring Data JPA application. How would you implement auditing to track changes in the entities?
- Implement custom auditing logic by intercepting entity changes in service methods.
- Leverage Spring Data JPA's built-in auditing support by adding annotations and configuration.
- Manually log entity changes in application logs for auditing purposes.
- Use database triggers and stored procedures to capture entity changes.
When implementing auditing features in a Spring Data JPA application, the recommended approach is to leverage Spring Data JPA's built-in auditing support. This can be achieved by adding annotations like @CreatedBy, @LastModifiedBy, and @CreatedDate, along with appropriate configuration. Implementing custom auditing logic in service methods can be error-prone and difficult to maintain. Using database triggers and stored procedures is not a typical approach for Spring Data JPA auditing. Manually logging entity changes is not a comprehensive auditing solution.
How can you configure a Spring Boot application to act as an OAuth2 Resource Server?
- Using @EnableResourceServer annotation.
- Adding the @EnableOAuth2Resource annotation.
- Creating a new SecurityConfig class.
- Modifying the application.properties file.
To configure a Spring Boot application as an OAuth2 Resource Server, you typically use the @EnableResourceServer annotation. This annotation enables OAuth2 security features in your application, allowing it to validate access tokens and handle resource requests securely. The other options are not standard practices for configuring a Spring Boot application as an OAuth2 Resource Server.
If you were to set up a highly available service discovery system using Spring Cloud and Eureka, how would you go about it, and what considerations would you need to account for?
- Implement multiple Eureka server instances in different availability zones. Configure client applications to register with all Eureka servers. Use a load balancer in front of Eureka servers.
- Use Apache ZooKeeper instead of Eureka for better availability. Implement custom health checks for service instances. Deploy Eureka in a Docker swarm cluster. Enable OAuth2 security for service registration.
- Use a single Eureka server for simplicity. Utilize Spring Cloud Circuit Breaker to handle failures. Configure automatic registration and deregistration of services. Set up a Redis cache for service registry data.
- Use an external DNS service to resolve service names. Deploy a single Eureka server and rely on client-side load balancing. Implement a custom service registration mechanism using Kafka.
Setting up a highly available service discovery system with Spring Cloud and Eureka involves multiple steps. Implementing multiple Eureka server instances in different availability zones ensures redundancy. Configuring clients to register with all Eureka servers ensures service registration reliability. Using a load balancer in front of Eureka servers helps distribute requests. These considerations help in achieving high availability for service discovery.
Which of the following is a primary benefit of using JWT tokens in Spring Boot security?
- Centralized user management.
- Complex and lengthy token format.
- Enhanced encryption capabilities.
- Statelessness and scalability.
A primary benefit of using JWT (JSON Web Tokens) in Spring Boot security is statelessness and scalability. JWTs are self-contained and do not require server-side storage or session management, making them suitable for distributed and stateless architectures. They do not provide centralized user management, have a compact token format, and while they offer strong encryption capabilities, statelessness is a more notable advantage.
The order in which auto-configurations are applied in Spring Boot can be influenced using the _____ property.
- spring.autoconfig.order
- spring.autoconfigure.exclude
- spring.autoconfigure.order
- spring.config.order
The order in which auto-configurations are applied in Spring Boot can be influenced using the "spring.autoconfigure.order" property. By specifying the desired order, developers can control the sequence in which auto-configurations are applied, which can be important for resolving conflicts or ensuring that certain configurations are applied first.
Imagine you are designing a Spring Cloud microservices application. How would you implement inter-service communication and ensure load balancing among the service instances?
- Using RESTful HTTP requests with hardcoded URLs.
- Implementing a service registry like Netflix Eureka and using client-side load balancing.
- Hardcoding IP addresses of service instances.
- Avoiding inter-service communication.
To ensure dynamic and scalable inter-service communication, you should use a service registry like Netflix Eureka and client-side load balancing. Hardcoding URLs or IP addresses is not a scalable solution. Avoiding inter-service communication is not practical in a microservices architecture.
_____ is a technique used to minimize the overhead of opening and closing database connections in a Spring Boot application.
- Aspect-oriented programming
- Connection pooling
- Data binding
- Dependency injection
Connection pooling is a technique used to minimize the overhead of opening and closing database connections in a Spring Boot application. It involves creating a pool of pre-initialized database connections that can be reused, reducing the time and resources required to establish new connections each time a database interaction is needed.
When creating a custom Auto Configuration, how do you ensure that it is processed after a specific Auto Configuration?
- By using the @AutoConfigureAfter annotation and specifying the class or classes that should be processed before.
- By setting the spring.autoconfigure.order property in application.properties or application.yml to control the order of Auto Configuration processing.
- By using the @DependsOn annotation and specifying the names of the beans that should be created before the custom Auto Configuration.
- By extending the AutoConfigurationSorter class and implementing custom sorting logic based on your requirements.
You can ensure that a custom Auto Configuration is processed after a specific Auto Configuration by using the @AutoConfigureAfter annotation and specifying the class or classes that should be processed before your custom configuration. This allows you to define the order of Auto Configuration processing. The other options do not provide a direct way to control the order of Auto Configuration.