参考博客：https://www.cnblogs.com/duanxz/p/7493276.html
spring中的@Scope注解 https://www.cnblogs.com/lonecloud/p/5745902.html
spring中的@Qualifier注解 https://www.cnblogs.com/smileLuckBoy/p/5801678.html
spring中@Resource和@Autowired区别： https://www.cnblogs.com/think-in-java/p/5474740.html