Examples

For example:

import jakarta.persistence.Column;

@DomainObject
public class Customer {
    public static class EmailSpecification extends AbstractSpecification<String> {
        public String satisfiesSafely(String proposed) {
            return EmailUtil.ensureValidEmail(proposed);    (1)
        }
    }
    @@Column(nullable=true)                                 (2)
    @Property(
        maxLength=30,
        mustSatisfy=EmailSpecification.class,
        regexPattern = "(\\w+\\.)*\\w+@(\\w+\\.)+[A-Za-z]+",
        regexPatternFlags=Pattern.CASE_INSENSITIVE
    )
    @Getter @Setter
    private String emailAddress;

    // ...
}
1 the (fictitious) EmailUtil.ensureValid(…​) (omitted for brevity) returns a string explaining if an email is invalid
2 generally use instead of the @Property#optionality attribute

The annotation is one of a handful (others including @Collection, @CollectionLayout and @PropertyLayout) that can also be applied to the field, rather than the getter method. This is specifically so that boilerplate-busting tools such as Project Lombok can be used.

Usage Notes