SpringBoot Validator

在开发中，往往需要对应前端穿过来的参数进行校验，有时候会显得参数校验过于臃肿，但是又不得不做。这里引入 Hibernate Validator ，它支持属性、字段、返回值、方法参数、类级别的校验，而且SpringBoot可以很轻松集成。

Maven

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-validation</artifactId>
</dependency>

配置

配置 ValidatorFactory。

@Configuration
public class ValidatorConfig {@Beanpublic Validator validator() {ValidatorFactory validatorFactory = Validation.byProvider(HibernateValidator.class).configure().failFast(true).buildValidatorFactory();return validatorFactory.getValidator();}
}

配置校验失败异常处理。

@ControllerAdvice
public class ExceptionAdvice {@ExceptionHandler(value = MethodArgumentNotValidException.class)public ResponseEntity<ApiResult<?>> methodArgumentNotValidException(MethodArgumentNotValidException exception) {List<ObjectError> allErrors = exception.getBindingResult().getAllErrors();Iterator<ObjectError> iterator = allErrors.iterator();StringBuilder builder = new StringBuilder();while (iterator.hasNext()) {ObjectError error = iterator.next();String message = error.getObjectName() + ":" + error.getDefaultMessage();builder.append(message);}return new ResponseEntity<>(new ApiResult<>(HttpStatus.BAD_REQUEST.value(), builder.toString()), HttpStatus.BAD_REQUEST);}@ExceptionHandler(value = ConstraintViolationException.class)public ResponseEntity<ApiResult<?>> constraintViolationException(ConstraintViolationException exception) {Set<ConstraintViolation<?>> constraintViolations = exception.getConstraintViolations();Iterator<ConstraintViolation<?>> iterator = constraintViolations.iterator();StringBuilder builder = new StringBuilder();while (iterator.hasNext()) {ConstraintViolation<?> constraint = iterator.next();String message = constraint.getPropertyPath() + ":" + constraint.getMessage();builder.append(message);}return new ResponseEntity<>(new ApiResult<>(HttpStatus.BAD_REQUEST.value(), builder.toString()), HttpStatus.BAD_REQUEST);}
}

属性级别校验

@Data
public class Car {@NotNullprivate String manufacturer;@AssertTrueprivate boolean isRegistered;public Car(String manufacturer, boolean isRegistered) {this.manufacturer = manufacturer;this.isRegistered = isRegistered;}
}

controller编写

@Validated 开启参数校验，如果参数校验失败，将抛出 MethodArgumentNotValidException 异常。

@RestController
@RequestMapping("/test")
public class TestController {@PostMapping("/car")public void testCar(@Validated @RequestBody Car car) {System.out.println(car);}
}

get方法开启参数校验，要在类级别上使用 @Validated，如果校验失败，将抛出 ConstraintViolationException 异常。

@RestController
@RequestMapping("/test")
@Validated
public class TestController {@GetMapping("/testGet")public void testGet(@Max(23) Integer id) {System.out.println(id);}
}

分组校验

有时候我们需要对需要校验的字段进行分组，方便复用。这里定义一个对象 GroupDomain，分了三个组。注意：Hibernate Validator 有个默认组的概念，如果校验限制没有被指定分组，那么属于默认分组。id 、column1 是属于默认分组(Default)。

@Data
public class GroupDomain {@NotNull(message = "id can not null")private Integer id;@NotBlank(message = "column1 can not null")private String column1;@NotBlank(message = "column2 can not null", groups = GroupCheck2.class)private String column2;@NotBlank(message = "column3 can not null", groups = GroupCheck3.class)private String column3;@NotBlank(message = "column4 can not null", groups = GroupCheck4.class)private String column4;
}

public interface GroupCheck2 {}
public interface GroupCheck3 {}
public interface GroupCheck4 {}

controller编写

@RestController
@RequestMapping("/group")
public class GroupController {// id不能为null，column1不能为空串。其他字段不校验@PostMapping("/defaultGroup")public void defaultGroup(@Validated @RequestBody GroupDomain groupDomain) {System.out.println(groupDomain);}// column2不能为空串。其他字段不校验@PostMapping("/oneGroup")public void oneGroup(@Validated(GroupCheck1.class) @RequestBody GroupDomain groupDomain) {System.out.println(groupDomain);}// column3不能为空串。其他字段不校验@PostMapping("/twoGroup")public void twoGroup(@Validated(GroupCheck2.class) @RequestBody GroupDomain groupDomain) {System.out.println(groupDomain);}// column4不能为空串。其他字段不校验@PostMapping("/threeGroup")public void threeGroup(@Validated(GroupCheck3.class) @RequestBody GroupDomain groupDomain) {System.out.println(groupDomain);}
}

分组顺序

当校验指定多个分组时，校验的顺序是不能确定的，我们可以指定分组校验的顺序。

@RestController
@RequestMapping("/group")
public class GroupController {@PostMapping("/fourGroup")public void fourGroup(@Validated(GroupChecks.class) @RequestBody GroupDomain groupDomain) {System.out.println(groupDomain);}
}

@GroupSequence(value = {GroupCheck4.class, GroupCheck3.class, GroupCheck2.class})
public interface GroupChecks {}

级联

使用 @Valid 注解可以使用级联方式校验。

public class Driver {@Min(value = 18, message = "You have to be 18 to drive a car", groups = DriverChecks.class)private int age;@AssertTrue(message = "You first have to pass the driving test", groups = DriverChecks.class)private boolean hasDrivingLicense;// getter and setter
}

public class Car {@NotNullprivate String manufacturer;@NotNull@Size(min = 2, max = 14)private String licensePlate;@Min(2)private int seatCount;@AssertTrue(message = "The car has to pass the vehicle inspection first",groups = CarChecks.class)private boolean passedVehicleInspection;@Validprivate Driver driver;// getter and setter
}

自定义校验

Hibernate validator 内置很多校验注解，它也支持自定义校验注解。

自定义注解，来校验字符串是否为大小写。

定义一个枚举

public enum CaseMode {UPPER, LOWER
}

定义注解

自定义 @CheckCase 注解，有三个属性是必选要有的：message、groups、payload。注解 @Constraint 来定义由谁去处理被 @CheckCase 标记的JavaBean的属性。

@Target({ FIELD, METHOD, PARAMETER, ANNOTATION_TYPE, TYPE_USE })
@Retention(RUNTIME)
@Constraint(validatedBy = CheckCaseValidator.class)
@Documented
@Repeatable(CheckCase.List.class)
public @interface CheckCase {// 这个是必选有的String message() default "{com.example.hibernate.constraint.custom.CheckCase.message}";// 这个是必选有的Class<?>[] groups() default {};// 这个是必选有的Class<? extends Payload>[] payload() default {};CaseMode value();@Target({ FIELD, METHOD, PARAMETER, ANNOTATION_TYPE })@Retention(RUNTIME)@Documented@interface List {CheckCase[] value();}
}

定义 CheckCaseValidator

自定义 CheckCaseValidator 验证器，它实现了 ConstraintValidator 接口

public class CheckCaseValidator implements ConstraintValidator<CheckCase, String> {private CaseMode caseMode;@Overridepublic boolean isValid(String object, ConstraintValidatorContext constraintValidatorContext) {if (object == null) {return true;}boolean isValid;if (caseMode == CaseMode.UPPER) {isValid = object.equals(object.toUpperCase());} else {isValid = object.equals(object.toLowerCase());}return isValid;}@Overridepublic void initialize(CheckCase constraintAnnotation) {this.caseMode = constraintAnnotation.value();}
}

参考

Hibernate Validator官网
springboot中hibernate validator校验模式，分组校验，自定义校验_morris131的博客-CSDN博客_validator分组校验