When creating a custom query in Spring Data JPA, the @Query annotation is used to modify the underlying query execution. It allows developers to define custom JPQL or native SQL queries and attach them to repository methods. This annotation provides flexibility in crafting specific queries tailored to the application's needs.

To enable method security annotations in a Spring Security configuration class, you should use the @EnableMethodSecurity annotation. This annotation allows you to configure method-level security in your application.

In Spring Boot, you can configure property sources in a specific order by using the spring.config.order property. This property allows you to specify the order in which configuration files are processed, with lower values indicating higher precedence. While other options are used in Spring Boot for property configuration, they do not control the order of property sources.

To test security configurations in Spring Boot applications, you should consider using @SpringBootTest. This annotation allows you to load the complete application context and test the security configurations effectively.

In Spring Boot, an effective way to implement a cache-aside caching strategy is by using annotations like @Cacheable and @CacheEvict. These annotations allow developers to specify caching behavior for specific methods, making it easier to cache data as needed and evict it when necessary. Options 2, 3, and 4 are not typically associated with cache-aside caching.

In Spring Data JPA, you can create a custom query method by simply adding a method to the repository interface with a name following Spring's naming conventions. Spring Data JPA will automatically generate the query based on the method name, allowing you to perform database operations without writing explicit SQL queries. The other options either involve using native SQL queries or do not adhere to the Spring Data JPA conventions for creating custom queries.

In Spring Boot, you can handle exceptions thrown by a controller method using the @ExceptionHandler annotation. This annotation allows you to define methods that can handle specific exceptions or exception types. Using System.out.println() statements is not the recommended way to handle exceptions, and not handling exceptions is not a valid approach. Defining a separate error controller is a possible strategy but less commonly used.

The @Valid annotation in a method signature within a Controller enables request parameter validation for all parameters of the annotated method. This ensures that incoming request parameters are validated against defined constraints before the method is executed. Option 2 is not accurate as the @Valid annotation itself doesn't control whether the method is called or not. Option 3 is incorrect as @Valid is related to input validation, not response validation. Option 4 is also incorrect.

In a Spring Boot application, the @EnableOAuth2AuthorizationServer annotation is used to enable OAuth2 Authorization Server features. This annotation is crucial when you want your Spring Boot application to act as an OAuth2 Authorization Server. It allows you to configure and provide OAuth2 tokens to clients securely.

You can create a custom query method in a Spring Data JPA repository by using the @Query annotation with JPQL (Java Persistence Query Language). This allows you to define custom queries in your repository interface. Extending the CrudRepository interface provides basic CRUD operations but doesn't allow you to create custom queries directly. The @NamedQuery annotation is used for predefined queries in the entity class, and there's no @CustomQuery annotation in Spring Data JPA.