Question

我知道之前曾有人问过这个问题，但是很遗憾，我无法获得答案（How to validate field level constraint before class level constraint?）。

我有以下Pojo：

@ValidBalanceData(allowableBalanceDifference = 0.01)
public class Mutation {

    @NotNull() private BigDecimal balanceBefore;

    @NotNull() private BigDecimal balanceAfter;

    @NotNull() private BigDecimal amount;

    ....
}

我已经实现了ValidBalanceData批注：

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = BalanceDataConstraintChecker.class)
public @interface ValidBalanceData {
    String message() default "{nl.smith.balanceData.message}";

    double allowableBalanceDifference();

    Class<?>[] groups() default {};

    Class<? extends Payload>[] payload() default {};
}

我还实现了validatedBy类。不幸的是，ValidBalanceData约束先于NotNull约束进行验证。由于ValidBalanceData约束假定balanceBefore，balanceAfter和amount值不为null，因此将导致Nullpointer异常。我该如何解决这个问题？有人可以给我一个有效的示例（使用@GroupSequence和字段）吗？

Answer 1

我找到了答案：

@GroupSequence({ FieldChecks.class, Mutation.class })
@ValidBalanceData(allowableBalanceDifference = 0.01, groups =  Default.class)
public class Mutation {

private Integer id;

@NotNull(groups = FieldChecks.class)
private BigDecimal balanceBefore;

@NotNull(groups = FieldChecks.class)
private BigDecimal balanceAfter;

@NotNull(groups = FieldChecks.class)
private BigDecimal amount;

....

}

FieldChecks是用户定义的空标记接口，而javax.validation.groups.Default来自验证jar。

Java bean验证

1 个答案: