承接Hibernate Validator 6.0.7.Final 之一（宣告Bean約束之約束的繼承性之一）。本文使用field級別的約束來測試一下約束的繼承性。

• 父類

public class Car {

    @NotNull(message = "製造商不能為空")
    private String manufacture;

    @Min(value = 2, message = "座位數量不能小於2")
    private int seatCount;

    public String getManufacture() {
        return
 
 manufacture;
    }

    public void setManufacture(String manufacture) {
        this.manufacture = manufacture;
    }

    public int getSeatCount() {
        return seatCount;
    }

    public void setSeatCount(int seatCount) {
        this.seatCount = seatCount;
    }
}

• 子類

public class
 
 RentalCar extends Car {

    @NotNull(message = "租賃站不能為空")
    private String rentalStation;

    @Max(value = 5, message = "座位數量不能大於5")
    private int seatCount;

    public String getRentalStation() {
        return rentalStation;
    }

    public void setRentalStation(String rentalStation) {
        this
 
.rentalStation = rentalStation;
    }

    @Override
    public int getSeatCount() {
        return seatCount;
    }

    @Override
    public void setSeatCount(int seatCount) {
        this.seatCount = seatCount;
    }
}

• 測試

    @Test
    public void inheritanceConstraintVer2Test() {
        com.qs.mmeng.hibernate.validator.constraints.declare.inheritance.ver2.RentalCar rentalCar =
                new com.qs.mmeng.hibernate.validator.constraints.declare.inheritance.ver2.RentalCar();
        // 違反了來自父類的約束
        rentalCar.setManufacture(null);
        rentalCar.setRentalStation(null);
        // 父類和子類的約束可以累加
        rentalCar.setSeatCount(6);
        Set<ConstraintViolation<com.qs.mmeng.hibernate.validator.constraints.declare.inheritance.ver2.RentalCar>> constraintViolations =
                validator.validate(rentalCar);
        logger.info("違反的約束的個數：{}", constraintViolations.size());
        for (ConstraintViolation<com.qs.mmeng.hibernate.validator.constraints.declare.inheritance.ver2.RentalCar> constraintViolation : constraintViolations) {
            logger.info("違反的約束：{}", constraintViolation.getMessage());
        }
    }

• 檢視
  

注意，從列印的結果可以看到使用field級別的約束的時候，違反的約束的個數是4。