Spring Boot 中使用自定义 Validator 校验两个参数的大小关系
🏷️ Spring Boot
创建一个自定义的注解
@RangeCompare
javaimport javax.validation.Constraint; import javax.validation.Payload; import java.lang.annotation.*; @Target({ElementType.TYPE, ElementType.ANNOTATION_TYPE}) @Retention(RetentionPolicy.RUNTIME) @Constraint(validatedBy = {RangeCompareValidator.class}) @Documented public @interface RangeCompare { String message() default "起始值必须小于或等于结束值"; Class<?>[] groups() default {}; Class<? extends Payload>[] payload() default {}; String from(); String to(); @Target({ElementType.TYPE, ElementType.ANNOTATION_TYPE}) @Retention(RetentionPolicy.RUNTIME) @Documented public @interface List { RangeCompare[] value(); } }
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27其中最重要的是
@Constraint
注解,用于指示该注解包含哪些验证逻辑。@Constraint
注解的源码:java@Documented @Target({ ANNOTATION_TYPE }) @Retention(RUNTIME) public @interface Constraint { Class<? extends ConstraintValidator<?, ?>>[] validatedBy(); }
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6创建
@Constraint
注解中指定的约束验证器RangeCompareValidator
javaimport org.springframework.beans.BeanWrapper; import org.springframework.beans.BeanWrapperImpl; import javax.validation.ConstraintValidator; import javax.validation.ConstraintValidatorContext; import java.time.LocalDate; import java.time.LocalDateTime; import java.time.LocalTime; public class RangeCompareValidator implements ConstraintValidator<RangeCompare, Object> { private String from; private String to; @Override public void initialize(RangeCompare constraint) { from = constraint.from(); to = constraint.to(); } @Override public boolean isValid(Object value, ConstraintValidatorContext context) { BeanWrapper beanWrapper = new BeanWrapperImpl(value); Object fromValue = beanWrapper.getPropertyValue(from); Object toValue = beanWrapper.getPropertyValue(to); if (fromValue == null || toValue == null) { return true; } if (fromValue instanceof Number && toValue instanceof Number) { return ((Number) fromValue).doubleValue() <= ((Number) toValue).doubleValue(); } if (fromValue instanceof LocalDate && toValue instanceof LocalDate) { return !((LocalDate) fromValue).isAfter(((LocalDate) toValue)); } if (fromValue instanceof LocalDateTime && toValue instanceof LocalDateTime) { return !((LocalDateTime) fromValue).isAfter(((LocalDateTime) toValue)); } if (fromValue instanceof LocalTime && toValue instanceof LocalTime) { return !((LocalTime) fromValue).isAfter(((LocalTime) toValue)); } throw new IllegalArgumentException("只支持数字或日期类型的比较"); } }
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50ConstraintValidator
接口定义如下:javapackage javax.validation; import java.lang.annotation.Annotation; import javax.validation.constraintvalidation.SupportedValidationTarget; public interface ConstraintValidator<A extends Annotation, T> { default void initialize(A constraintAnnotation) {} boolean isValid(T value, ConstraintValidatorContext context); }
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12ConstraintValidator
接口支持两个泛型参数:A extends Annotation
: 验证对应的注解类型T
:验证的目标类型
添加全局的异常处理器
参数验证不通过时会被
@ExceptionHandler(MethodArgumentNotValidException.class)
所捕获,这样就不必在每个接口中处理验证结果了。javaimport lombok.extern.slf4j.Slf4j; import org.springframework.context.support.DefaultMessageSourceResolvable; import org.springframework.http.HttpStatus; import org.springframework.web.bind.MethodArgumentNotValidException; import org.springframework.web.bind.annotation.ControllerAdvice; import org.springframework.web.bind.annotation.ExceptionHandler; import org.springframework.web.bind.annotation.ResponseBody; import org.springframework.web.bind.annotation.ResponseStatus; import java.util.stream.Collectors; import java.util.stream.Stream; @ControllerAdvice @Slf4j public class GlobalExceptionAdvice { @ExceptionHandler(MethodArgumentNotValidException.class) @ResponseStatus(HttpStatus.OK) @ResponseBody public ResponseInfo<Object> handleMethodArgumentNotValidException(MethodArgumentNotValidException ex) { String errors = Stream.concat( ex.getBindingResult().getFieldErrors().stream().map(m -> m.getField() + ":" + m.getDefaultMessage()), ex.getBindingResult().getGlobalErrors().stream().map(DefaultMessageSourceResolvable::getDefaultMessage)) .collect(Collectors.joining(",")); log.warn("参数错误[{}]", errors); return ResponseInfo.buildError(errors); } }
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28参数类上添加
@RangeCompare
注解javaimport io.swagger.annotations.ApiModelProperty; import lombok.Data; import java.time.LocalDate; @Data @RangeCompare(from = "fromDate", to = "toDate", message = "起始日期必须小于或等于结束日期") public class TimeRangeParam { @ApiModelProperty("起始日期") private LocalDate fromDate; @ApiModelProperty("结束日期") private LocalDate toDate; }
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16接口参数上添加
@Validated
注解java@PostMapping(value = "search") public ResponseInfo<Object> search(@Validated @RequestBody TimeRangeParam req) { // do something }
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