Adding JSR 303 constraints to persistent fields

JSR 303 (bean validation) defines a standard approach for annotations-based JavaBeans validation. In this recipe we'll look at how Spring Roo's field command can be used to add JSR 303 validation constraints to persistent fields of entities.

The following table shows the validation constraints that apply to fields defined in the Flight entity and FlightKey class of our flight-app project:

Persistent field	Constraint	JSR 303 annotation
Flight -> createdDate	Not null	@NotNull
Flight -> createdBy	Not null	@NotNull
Flight -> numOfSeats	Not null Maximum seats 200 Minimum seats 100	@NotNull @DecimalMax("200") @DecimalMin("100")
Flight -> origin	Not null Maximum length of value of origin is 20, minimum length is 3	@NotNull @Size(min=3, max=20)
Flight -> destination	Not null Maximum length of value of destination is 20, minimum length is 3	@NotNull @Size(min=3, max=20)
FlightKey -> flightId...