我看 MVC 设计中 dao 层和 service 都说要加一个 dao.impl 而我在实际应用中感觉加一个 dao.impl 非常麻烦，比如我需要修改 dao.impl 还要修改 dao 这样不增加了负担吗？他的好处是干什么用的，一直没明白。
MVC
dao
service
dao.impl
ringa_lee
This is just using the interface. It is recommended that you first understand the benefits of using the interface
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This is just using the interface. It is recommended that you first understand the benefits of using the interface