i use hibernate-tools and ant to generate .hbm files, but those files come out like this:
......
<property name="countryUuid" column="COUNTRY_UUID"/>
......

In fact ,the property "countryUuid" is not allowed null in database.
So what i want is like this:
.....
<property name="countryUuid" column="COUNTRY_UUID" not-null="true"/>
......

Is there any way or file to config this? I'm new in using hibernate-tools, and i need your help.

Thank you!!

Make sure that the corresponding database column has a NOT NULL constraint in the first place.
At least on Oracle, reveng is picking that one up reliably.

Other than that, you can add column properties in hibernate.reveng.xml. I haven't needed that for myself, so I'd have to dig around a bit to find out what needs to be done.