package org.hibernate.validator.referenceguide.chapter03.cascaded.collection; import javax.validation.constraints.NotNull; import javax.validation.constraints.Size; public class Car { @NotNull private String manufacturer; @NotNull @Size(min = 2, max = 14) private String licensePlate; public Car(String manufacturer, String licencePlate) { this.manufacturer = manufacturer; this.licensePlate = licencePlate; } //getters and setters ... }