Common annotations and instructions of SpringBoot

@Configuration regards a class as an IoC container, and if @Bean is registered on one of its method headers, it will be used as a Bean in the Spring container. 
@Scope annotation scope 
@Lazy(true) means lazy initialization 
@Service is used to annotate business layer components, 
@Controller is used to annotate control layer components (such as actions in struts) 
@Repository is used to annotate data access components, namely DAO components. 
@Component refers to components in general. When components are not well classified, we can use this annotation for annotation. 
@Scope is used to specify the scope of the scope (used on the class) 
@PostConstruct is used to specify the initialization method (used on the method) 
@PreDestory is used to specify the destruction method (used on the method) 
@Resource is assembled by name by default. Beans that do not match the name will be assembled by type. 
@DependsOn: Define the order of Bean initialization and destruction @Primary: 
When there are multiple Bean candidates during automatic assembly, the bean annotated as @Primary will be the first choice, otherwise an exception will be thrown. 
@Autowired is assembled by type by default. If we want to use assembly by name, we can use it in conjunction with @Qualifier annotation 
@Autowired @Qualifier("personDaoBean") There are multiple instances for use