@Bean 和@ Component的区别

1. @Component auto detects and configures the beans using classpath scanning whereas @Bean explicitly declares a single bean, rather than letting Spring do it automatically.
2. @Component does not decouple the declaration of the bean from the class definition where as @Bean decouples the declaration of the bean from the class definition.
3. @Component is a class level annotation where as @Bean is a method level annotation and name of the method serves as the bean name.
4. @Component need not to be used with the @Configuration annotation where as @Bean annotation has to be used within the class which is annotated with @Configuration.
5. We cannot create a bean of a class using @Component, if the class is outside spring container whereas we can create a bean of a class using @Bean even if the class is present outside the spring container.
6. @Component has different specializations like @Controller, @Repository and @Service whereas @Bean has no specializations.

1. component ：  1  利用spring 类路径扫描，

　　　　　　　　2. 写在类上，和类定义不分离。 

　　　　　　　　3. 不需要配合 @configuration注解

2. Bean ：  .当类不受spring控制的时候，写一个方法，返回某个不受spring控制的类的对象。 这样就能在spring里注入一个bean。

　　　　　　配合configuration注解

　参考：https://stackoverflow.com/questions/10604298/spring-component-versus-bean