To conditionally apply caching logic in Spring Boot, developers can use the _____ expression in caching annotations.
- @CacheCondition
- @Cacheable
- @CachingExpression
- @ConditionalCache
To conditionally apply caching logic in Spring Boot, developers use the @Cacheable annotation. This annotation allows them to specify conditions under which the caching logic should be applied, typically by providing a SpEL (Spring Expression Language) expression. It's a powerful tool for selectively caching method results.
Which annotation is used in Spring Boot to conditionally enable or disable certain parts of auto-configuration based on the presence of specific properties?
- @ConditionalOnProperty
- @EnableAutoConfiguration
- @ConditionalOnClass
- @Configuration
In Spring Boot, the @ConditionalOnProperty annotation is used to conditionally enable or disable certain parts of auto-configuration based on the presence or absence of specific properties in the application.properties file. This provides fine-grained control over which auto-configuration options are activated based on the application's configuration. The other annotations serve different purposes in Spring Boot.
In Spring, the process of creating an instance of a bean, wiring it up, and making it available for use is called _____
- Aspect-Oriented Programming
- Bean Configuration
- Dependency Injection
- Inversion of Control (IoC)
In Spring, the process of creating an instance of a bean, wiring it up, and making it available for use is called "Dependency Injection." This core concept of Spring allows for the automatic injection of dependencies into a class, making it more flexible and easier to manage. Inversion of Control (IoC) is a broader concept that encompasses Dependency Injection. Aspect-Oriented Programming (AOP) and Bean Configuration are related but not the exact terms used for this specific process.
To include Spring MVC in a Spring Boot project, the _____ starter dependency should be added.
- spring-boot-mvc-starter
- spring-boot-web-starter
- spring-mvc-starter
- spring-web-starter
To include Spring MVC in a Spring Boot project, the spring-boot-starter-web dependency should be added. This starter includes the necessary libraries and configurations to set up Spring MVC in a Spring Boot application. It simplifies the integration of Spring MVC and provides a solid foundation for building web applications using Spring Boot.
You notice that a Spring Boot application is not evicting cache entries as expected, leading to outdated data being served. How would you diagnose and resolve this issue?
- Check the cache eviction policy configuration and ensure it's appropriately set.
- Increase the cache timeout values to prevent eviction.
- Monitor the cache utilization and memory consumption to identify issues.
- Restart the Spring Boot application to clear the cache.
When cache entries are not being evicted as expected, it's crucial to check and correct the cache eviction policy configuration. Increasing timeout values may not solve the problem and could lead to stale data. Monitoring cache utilization and memory consumption helps identify issues. Restarting the application is a heavy-handed approach and may not address the root cause.
In a Spring Cloud microservices architecture, _____ is primarily used for allowing services to discover each other.
- Eureka
- Feign
- Hystrix
- Ribbon
In a Spring Cloud microservices architecture, Eureka is primarily used for allowing services to discover each other. Eureka is a service registry and discovery server that enables microservices to find and communicate with each other. When a service starts up, it registers itself with Eureka, making it discoverable by other services. Eureka maintains a dynamic directory of available services, allowing for automatic load balancing and failover.
In Spring Security, what is the significance of configuring a global method security, and how does it differ from standard method security configurations?
- Global method security applies only to controllers, whereas standard configurations apply to service classes.
- Global method security configurations apply to all methods by default, while standard configurations require annotation-based security settings on individual methods.
- Global method security is used for securing web pages, while standard configurations are used for securing REST APIs.
- There is no difference between global method security and standard method security.
Configuring global method security allows you to set default security settings for all methods, which simplifies security setup. Standard configurations require you to annotate each method individually for security settings.
The _____ annotation in Spring is used to give a preference to a bean when multiple beans of the same type exist.
- @Primary
- @Qualifier
- @PreferencedBean
- @Priority
The @Primary annotation in Spring is used to give a preference to a bean when multiple beans of the same type exist. It tells Spring which bean should be considered as the primary candidate for autowiring when there are multiple candidates of the same type. The other options, such as @Qualifier, @PreferencedBean, and @Priority, do not serve the same purpose as @Primary.
What is the role of the @Repository annotation in the context of database interaction and exception translation?
- It indicates that the class is responsible for generating exceptions when database operations fail.
- It marks a class as a repository, enabling Spring Data JPA to automatically generate database queries.
- It specifies the database schema for the corresponding class.
- It turns the class into a RESTful web service for database operations.
The @Repository annotation in Spring is used to mark a class as a repository, especially in the context of Spring Data JPA. It helps in automatic generation of database queries based on method names. It does not generate exceptions or specify the database schema. Its primary role is to enable Spring to manage database operations and perform exception translation when necessary. It is not related to creating RESTful web services.
What strategies can be employed in Spring Boot to handle database connection failures and retries?
- Implement retry mechanisms with libraries like Spring Retry.
- Increase the database timeout to reduce connection failures.
- Manually restart the Spring Boot application on failure.
- Use a backup database in case of primary database failure.
In Spring Boot, you can handle database connection failures and retries by implementing retry mechanisms with libraries like Spring Retry. This allows your application to automatically retry failed database operations, enhancing resilience. Using a backup database or increasing the database timeout can be part of a broader strategy, but they don't directly address retries. Manually restarting the application is not a recommended approach for handling failures.