https://blog.csdn.net/z3133464733/article/details/79189699
init ，destroy，postconstruct，predestroy。从上面链接理解到得好像不太对
没看https://blog.csdn.net/u010900754/article/details/95018759
@configuration里面 @value 取配置，@component里面 @autowired把 值注入进来