In a Spring Cloud microservices environment, centralized configuration management is typically implemented using Spring Cloud Config Server, which allows you to store and manage configurations in a centralized location.

In Spring Boot, the @RequestBody annotation is used to bind the value of the HTTP request body to a method parameter in a controller method. This allows you to access and process the data sent in the request body. The other options represent different types or concepts and are not used for binding request bodies to controller methods.

In Spring Boot, the @CacheEvict annotation is used to perform a cache eviction operation when a method is executed successfully. This annotation is useful when you want to remove specific cache entries or clear the cache entirely after a successful method execution, ensuring that you always have up-to-date data in your cache.

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.

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.

In Spring Boot, the @WebMvcTest annotation is used to simulate HTTP requests and test the web layers (controllers) without starting a full web server. It focuses on testing the web-related components of your application.

To handle validation errors globally across a Spring Boot application in a centralized manner, you should define a global exception handler using the @ControllerAdvice annotation. This allows you to handle validation errors uniformly across all controllers, promoting code reusability and centralization. Options 1 and 2 are incorrect as they involve handling errors at the controller level, and Option 4 is not recommended as it lacks centralization.

The @PreAuthorize annotation in Spring Security uses SpEL (Spring Expression Language) expressions to define access controls. SpEL allows you to write expressive and dynamic access control expressions based on the current authentication context.

The @RequestMapping annotation is used to map a web request to a specific handler method in a Spring Boot controller. It allows you to specify the URL path, HTTP method, and other parameters to define how the request should be routed to the appropriate method. The other options, such as @ResponseBody, @PostMapping, and @Autowired, serve different purposes in Spring Boot but are not used for request mapping.

In a Spring Boot project, the pom.xml file, which stands for Project Object Model, is used to define the project's dependencies, build configuration, and metadata. It's an XML file that manages project dependencies and configurations, making it a critical component of any Spring Boot project. This file is essential for Maven-based projects.