Why you need it?

Is your feature request related to a problem? Please describe in details

currently, in spring boot, config read chain is: system env -> spring environment -> default value -> original source read read(file,zk,nacos...depend on config type).

currently, when config type is file mode in spring boot, config read chain is: system env -> spring environment -> default value -> original source

if there is a value for the property, search returned. the situation may occur: the property not configed in spring and exist a default for it, so it will result a default value instead of read right property in file configuration.

How it could be?

A clear and concise description of what you want to happen. You can explain more about input of the feature, and output of it.

Other related information

Add any other context or screenshots about the feature request here.