您可以在spring上下文模式文件中找到更多信息。 以下内容来自spring-context-4.3.xsd

<conxtext:annotation-config />

Activates various annotations to be detected in bean classes: Spring's @Required and
@Autowired, as well as JSR 250's @PostConstruct, @PreDestroy and @Resource (if available),
JAX-WS's @WebServiceRef (if available), EJB 3's @EJB (if available), and JPA's
@PersistenceContext and @PersistenceUnit (if available). Alternatively, you may
choose to activate the individual BeanPostProcessors for those annotations.

Note: This tag does not activate processing of Spring's @Transactional or EJB 3's
@TransactionAttribute annotation. Consider the use of the <tx:annotation-driven>
tag for that purpose.

<context:component-scan>

Scans the classpath for annotated components that will be auto-registered as
Spring beans. By default, the Spring-provided @Component, @Repository, @Service, @Controller, @RestController, @ControllerAdvice, and @Configuration stereotypes    will be detected.

Note: This tag implies the effects of the 'annotation-config' tag, activating @Required,
@Autowired, @PostConstruct, @PreDestroy, @Resource, @PersistenceContext and @PersistenceUnit
annotations in the component classes, which is usually desired for autodetected components
(without external configuration). Turn off the 'annotation-config' attribute to deactivate
this default behavior, for example in order to use custom BeanPostProcessor definitions
for handling those annotations.

Note: You may use placeholders in package paths, but only resolved against system
properties (analogous to resource paths). A component scan results in new bean definitions
being registered; Spring's PropertySourcesPlaceholderConfigurer will apply to those bean
definitions just like to regular bean definitions, but it won't apply to the component
scan settings themselves.

我发现了一个很好的总结，说明哪些注释被哪些声明拾取。通过研究它，你会发现<context:component-scan/>识别了<context:annotation-config/>识别的注释的超集，即:

@组件，@服务，@存储库，@控制器，@端点 @Configuration， @Bean， @Lazy， @Scope， @Order， @Primary， @Profile， @DependsOn， @Import， @ImportResource

正如您所看到的，<context:component-scan/>逻辑上扩展了<context:annotation-config/>，具有CLASSPATH组件扫描和Java @Configuration特性。

两者之间的区别真的很简单!

<context:annotation-config /> 

允许您使用仅限于连接bean的属性和构造函数的注释!

而

<context:component-scan base-package="org.package"/> 

启用<context:annotation-config />可以做的所有事情，添加使用原型，例如..@组件，@服务，@存储库。因此，您可以连接整个bean，而不仅仅局限于构造函数或属性!

<context:annotation-config>标记告诉Spring扫描代码库，以自动解决包含@Autowired注释的类的依赖关系需求。

Spring 2.5还增加了对JSR-250注释的支持，比如@Resource、@PostConstruct和@PreDestroy。使用这些注释还要求在Spring容器中注册某些beanpostprocessor。与往常一样，这些可以注册为单独的bean定义，但也可以通过在spring配置中包含<context:annotation-config>标记来隐式注册。

摘自Spring文档中的基于注释的配置

Spring提供了自动检测“定型”类的功能，并在ApplicationContext中注册相应的BeanDefinitions。

根据org.springframework.stereotype的javadoc:

原型是表示类型或方法在整个体系结构中的角色的注释(在概念级别，而不是实现级别)。 例如:@控制器@服务@存储库等。 它们是供工具和方面使用的(成为切入点的理想目标)。

要自动检测这样的“原型”类，需要<context:component-scan>标记。

<context:component-scan>标记还告诉Spring在指定的包(及其所有子包)下扫描可注入bean的代码。

Spring允许您做两件事:

自动装配bean 自动发现bean

1. Autowiring Usually in applicationContext.xml you define beans and other beans are wired using constructor or setter methods. You can wire beans using XML or annotations. In case you use annotations, you need to activate annotations and you have to add <context:annotation-config /> in applicationContext.xml. This will simplify the structure of the tag from applicationContext.xml, because you will not have to manually wire beans (constructor or setter). You can use @Autowire annotation and the beans will be wired by type.

避免手动XML配置的一个步骤是

2. Autodiscovery Autodiscovery is simplifying the XML one step further, in the sense that you don't even need too add the <bean> tag in applicationContext.xml. You just mark the specific beans with one of the following annotation and Spring will automatically wire the marked beans and their dependencies into the Spring container. The annotations are as follow: @Controller, @Service, @Component, @Repository. By using <context:component-scan> and pointing the base package, Spring will auto-discover and wire the components into Spring container.

作为结论:

<context:annotation-config />被使用是为了能够使用 @ autowired注解 <context:component-scan />用于确定搜索 特定的bean和自动装配的尝试。

<context:annotation-config/> <!-- is used to activate the annotation for beans -->
<context:component-scan base-package="x.y.MyClass" /> <!-- is for the Spring IOC container to look for the beans in the base package. -->

要注意的另一个重要点是context:component-scan隐式调用context:annotation-config来激活bean上的注释。如果你不想让context:component-scan隐式地为你激活注释，你可以继续将context:component-scan的annotation-config元素设置为false。

总结:

<context:annotation-config/> <!-- activates the annotations --> 
<context:component-scan base-package="x.y.MyClass" /> <!-- activates the annotations + register the beans by looking inside the base-package -->