如何使用@DecimalMin和@DecimalMaxvalidationList ？
在我的Spring项目中，我有一个POJO类，它具有CMYK颜色的属性。 我希望这个属性由一个JSON数组表示，该数组恰好有4个浮点数。 每个数字必须介于0.0和1.0之间。 目前我正在努力validation这个属性。
我已经研究过，发现@DecimalMin和@DecimalMax注释不能用于Float或float （请参阅这个问题的答案）。 因此我已经放弃了List List而是使用List 。
这是我剥离的POJO课程：
public class Settings { @NotNull @Size(min = 4, max = 4) @DecimalMin("0") @DecimalMax("1") private List cmykColor; public List getCmykColor() { return cmykColor; } public void setCmykColor(List cmykColor) { this.cmykColor = cmykColor; } }
这里是JUnit测试：
@RunWith(SpringRunner.class) @SpringBootTest public class SettingsTest extends Assert { @Autowired private ObjectMapper objectMapper; @Autowired private Validator validator; // from org.springframework.validation private Errors validate(String json) throws IOException { Settings settings = objectMapper.readValue(json, Settings.class); Errors errors = new BeanPropertyBindingResult(settings, "settings"); validator.validate(settings, errors); return errors; } @Test public void testValid() throws IOException { String json = "{ \"cmykColor\": [0.5, 1.0, 0.3, 0.0] }"; Errors errors = validate(json); assertEquals(0, errors.getErrorCount()); } @Test public void testTooBig() throws IOException { String json = "{ \"cmykColor\": [0.5, 1.01, 0.3, 0.0] }"; Errors errors = validate(json); assertEquals(1, errors.getErrorCount()); } @Test public void testTooMany() throws IOException { String json = "{ \"cmykColor\": [0.5, 1.0, 0.3, 0.0, 0.0] }"; Errors errors = validate(json); assertEquals(1, errors.getErrorCount()); assertNotNull(errors.getFieldError("cmykColor")); } }
当我注释掉@DecimalMin("0")和@DecimalMax("1")注释时，所有测试用例都会成功，当然除了testTooBig测试用例，它依赖于@DecimalMax约束。
但是当我添加@DecimalMin("0")和@DecimalMax("1")注释时，我在所有测试用例中都得到以下exception，说没有用于DecimalMaxvalidationListvalidation器。
javax.validation.UnexpectedTypeException: HV000030: No validator could be found for constraint 'javax.validation.constraints.DecimalMax' validating type 'java.util.List'. Check configuration for 'cmykColor' at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintTree.getExceptionForNullValidator(ConstraintTree.java:108) at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintTree.getInitializedConstraintValidator(ConstraintTree.java:140) at org.hibernate.validator.internal.engine.constraintvalidation.SimpleConstraintTree.validateConstraints(SimpleConstraintTree.java:55) at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintTree.validateConstraints(ConstraintTree.java:73) at org.hibernate.validator.internal.metadata.core.MetaConstraint.doValidateConstraint(MetaConstraint.java:127) at org.hibernate.validator.internal.metadata.core.MetaConstraint.validateConstraint(MetaConstraint.java:120) at org.hibernate.validator.internal.engine.ValidatorImpl.validateMetaConstraint(ValidatorImpl.java:533) at org.hibernate.validator.internal.engine.ValidatorImpl.validateConstraintsForSingleDefaultGroupElement(ValidatorImpl.java:496) at org.hibernate.validator.internal.engine.ValidatorImpl.validateConstraintsForDefaultGroup(ValidatorImpl.java:465) at org.hibernate.validator.internal.engine.ValidatorImpl.validateConstraintsForCurrentGroup(ValidatorImpl.java:430) at org.hibernate.validator.internal.engine.ValidatorImpl.validateInContext(ValidatorImpl.java:380) at org.hibernate.validator.internal.engine.ValidatorImpl.validate(ValidatorImpl.java:169) at org.springframework.validation.beanvalidation.SpringValidatorAdapter.validate(SpringValidatorAdapter.java:104) at com.oce.spring.domain.SettingsTest.validate(SettingsTest.java:29) at com.oce.spring.domain.SettingsTest.testTooMany(SettingsTest.java:58) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ...
那么，我应该如何在List正确使用@DecimalMin("0")和@DecimalMax("1") ？
我们在Hibernate Validator 6.0.x中实现了容器元素约束。
因此升级到Hibernate Validator 6.0.x（6.0.9.Final是最新版本）和Bean Validation 2.0.1并执行如下操作：
@Size(...) private List<@DecimalMin(...) @DecimalMax(...) BigDecimal> cmykColor;
注意，Hibernate Validator 6.0的groupId是org.hibernate.validator。