这个问题我搜了一上午都木有解决
后来找到一个英文网站
It seems that some other bean (one that is not shown) has a property of the ClientDAOImpl type. Since the proxy created implements the ClientDAO interface, but does not extend ClientDAOImpl, you get an exception.
Check if any of the other beans have a method of the form: setClientDAO(ClientDAOImpl).
后来我发现，我写了一个service和一个serviceimpl，但是没有让serviceimpl继承service这个借口