When configuring an OAuth2 Resource Server in Spring Boot, the public_key_location property is used to specify the location of the public key for verifying JWT signatures. This key is essential for validating the authenticity and integrity of JWT tokens used for authentication and authorization. The other options are not typically used for specifying the public key location.

The @WebMvcTest annotation is used to load only the Web layer of the Spring application context, making it suitable for testing controllers and related components.

To conditionally exclude specific Auto Configurations, you can use the spring.autoconfigure.exclude property in your application.properties or application.yml file. This property allows you to specify the fully qualified names of the Auto Configuration classes you want to exclude. The other options do not provide a direct way to conditionally exclude Auto Configurations.

In Spring Boot, to perform integration testing and enable full application context loading, you use the @SpringBootTest annotation. This annotation loads the entire Spring application context, making it suitable for integration testing scenarios.

To customize the response body of a global exception handler method in Spring Boot, the method should return an object of type ResponseEntity. This allows you to create a custom response with specific status codes, headers, and response bodies when an exception is caught globally. It provides flexibility in crafting error responses tailored to your application's needs.

Optimizing a Spring Boot application for faster startup times involves strategies like minimizing the number of auto-configured beans, using lazy initialization for non-essential components, and optimizing classpath scanning. These approaches reduce the initial overhead and improve startup times. The other options, such as increasing auto-configured beans or increasing thread pool size without consideration, can lead to performance issues or longer startup times.

In Spring Boot, you can define hierarchical properties in a YAML configuration file using YAML nesting. YAML allows you to structure your configuration data hierarchically, making it easy to organize and manage complex configuration settings for your application. This helps in maintaining a clean and readable configuration.

Configuring a Data Source in a Spring Boot application is primarily done to establish a connection to a database. This is crucial for applications that need to interact with a database to store or retrieve data. While the other options are essential in a Spring Boot application, they are not the primary purpose of configuring a Data Source.

The @JpaTest annotation is used in Spring Boot to disable full auto-configuration and apply configuration relevant to JPA tests. It sets up an environment for testing JPA repositories. @SpringBootTest and @RunWith(SpringRunner.class) are more general-purpose testing annotations, while @AutoConfigureTestDatabase is used for configuring the test database.

The primary purpose of monitoring in a Spring Boot application is to identify critical issues. Monitoring helps you keep a close watch on the health and performance of your application in production. By continuously monitoring various metrics and endpoints provided by Spring Boot Actuator, you can quickly detect and respond to issues such as application failures, memory leaks, high CPU usage, and more. While other activities like enforcing security policies, optimizing database queries, and generating test reports are essential in software development, they are not the primary purpose of monitoring in a Spring Boot application.