To configure a custom cache manager in Spring Boot, you can define a bean of type CacheManager with the desired configuration in your application's configuration class. This bean will override the default cache manager, allowing you to customize caching behavior according to your needs. The other options are not standard ways to configure a custom cache manager. The @EnableCustomCaching and @CustomCacheManager annotations are not part of the standard Spring Boot framework, and directly setting the property is not a recommended approach.

In Spring Boot, you would use the @RestController annotation for creating components that handle HTTP requests and responses. Methods within this component should be annotated with @RequestMapping or its shortcut annotations like @GetMapping, @PostMapping, etc., to define the request mapping for each method. The @RestController annotation combines @Controller and @ResponseBody, making it suitable for RESTful web services.

In a Spring Boot project, additional metadata like project description and developer information is typically included in the README.md file in the project repository. This file serves as a documentation source and is commonly used to provide project details. While it's possible to include such information in other places like comments or build configuration files, the README.md is the most standard and prominent location.

The AccessDecisionManager is responsible for restricting access to application resources based on user roles in Spring Security. It evaluates user roles and permissions against the requested resource and decides whether access should be granted or denied. The other options play different roles in the Spring Security framework but are not primarily responsible for role-based access control.

The @WebMvcTest annotation is used for testing the web layer of a Spring Boot application. It loads only the web-related components, such as controllers, and mocks other components. In contrast, @SpringBootTest loads the entire application context, including all components.

In Spring Boot, the @ConditionalOnClass annotation is used to specify conditions based on the availability of a specific class in the classpath. It allows you to configure certain behavior only if a particular class is present, which can be useful for ensuring that your application behaves correctly in different environments or configurations.

In Spring Boot, Flyway is a popular tool used for database migration. It allows developers to version-control their database schema and apply changes to the database in a controlled and repeatable manner. While Spring Boot CLI, Spring Boot Actuator, and Spring Boot Initializer are useful in Spring Boot applications, they are not specifically designed for database migration tasks like Flyway.

In Spring Boot, the Flux class is used to represent a reactive stream of 0 or more items. It's a fundamental class in the Reactor library, which is at the core of Spring WebFlux. Flux is used to model sequences of data that can be processed asynchronously and reactively, making it suitable for building reactive applications.

The primary role of the JpaRepository interface in Spring Data JPA is to provide utility functions for working with JPA (Java Persistence API). It offers commonly used CRUD (Create, Read, Update, Delete) operations and query methods, allowing developers to interact with JPA entities without writing boilerplate code for these operations. It does not define custom queries or configure database connections.

In a microservices architecture, a centralized approach (option 2) for implementing SSO with OAuth2 and JWT is recommended. This centralization ensures uniformity and ease of management across all microservices. Implementing OAuth2 and JWT separately (option 1) could lead to inconsistency and complexity. While OAuth2 and OIDC (option 3) can be used together, they might not provide the same simplicity as a centralized solution. SAML-based SSO (option 4) is an alternative but may not be the best fit for a microservices setup.

To exclude a specific auto-configuration class in a Spring Boot application, you can specify exclusions in the application.properties file using the spring.autoconfigure.exclude property. This property allows you to list the fully-qualified names of the auto-configuration classes you want to exclude, ensuring they are not applied to your application.

The primary role of Spring Cloud in a microservices architecture is to provide tools and frameworks for service discovery, configuration management, load balancing, and other essential infrastructure services. It helps microservices locate and communicate with each other dynamically, promoting scalability and resilience.