When using Spring transaction management with annotation-driven mode, the @Transactional annotation will be processed by a TransactionInterceptor that implements the AOP advice interface. This interceptor will be applied to the target bean through a proxy that implements the same interface as the target bean. Therefore, when a method of the target bean is called from outside, it will actually invoke the proxy method, which will delegate to the interceptor and then to the actual target method.

However, when a method of the target bean is called from within the same bean, it will not go through the proxy and thus bypass the interceptor logic. In this case, when update1() calls update2(), it will not start a new transaction as specified by REQUIRES_NEW propagation level, but rather join the existing transaction initiated by update1() itself.

C . Dependencies between application components can be managed external to the components.

This is true because dependency injection allows the application components to declare their dependencies without creating or obtaining them directly.Instead, the dependencies are provided by an external entity, such as the Spring container, which can read the configuration from XML files, annotations, or Java code1.

D . Configuration can be externalized and centralized in a small set of files.

This is true because dependency injection enables the separation of concerns between the application logic and the configuration.The configuration can be stored in a small number of files that can be easily changed without affecting the source code2.

F . Dependency injection facilitates loose coupling between components.

This is true because dependency injection reduces the direct dependencies between components, making them more reusable and testable.It also allows for easier substitution of different implementations of the same interface3.

Spring Security is a framework that provides comprehensive security services for Java applications, such as authentication, authorization, encryption, session management, and more. One of its features is method security, which allows applying access control rules at the method level using annotations or XML configuration. Another feature is authentication, which is the process of verifying the identity of a user or a system. Spring Security supports various authentication mechanisms, such as username and password, tokens, certificates, etc., and can access authentication data from different sources, such as databases, LDAP directories, in-memory stores, etc.

A web slice test is a type of test in Spring Boot that focuses on testing only the web layer of an application, without starting a full server or requiring a real database. To isolate the web layer from other dependencies, such as services or repositories, mocks can be used to simulate their behavior and return predefined responses. To create and inject a mock for an existing bean in the application context, the @MockBean annotation can be used on a field or a parameter in the test class. This annotation will replace any existing bean of the same type with a mock created by Mockito.