Java SpringBoot Validation用法 Java SpringBoot Validation用法案例详解
罗小爬EX 人气:0提到输入参数的基本验证(非空、长度、大小、格式…),在以前我们还是通过手写代码,各种if、else、StringUtils.isEmpty、CollectionUtils.isEmpty…,真感觉快要疯了,太繁琐,Low爆了…,其实在Java生态提供了一套标准JSR-380(aka. Bean Validation 2.0,part of Jakarta EE and JavaSE),它已成为对象验证事实上的标准,这套标准可以通过注解的形式(如@NotNull, @Size…)来对bean的属性进行验证。而Hibernate Validator对这套标准进行了实现,SpringBoot Validation无缝集成了Hibernate Validator、自定义验证器、自动验证的功能。下文将对SpringBoot集成Validation进行展开。
注: 完整示例代码可参见GitHub:https://github.com/marqueeluo/spring-boot-validation-demo
constraints分类
JSR-380的支持的constrants注解汇总如下表:
分类 | 注解 | 适用对象 | null是否验证通过 | 说明 |
---|---|---|---|---|
非空 | @NotNull | 所有对象 | No | 不是null |
非空 | @NotEmpty | CharSequence, Collection, Map, Array | No | 不是null、不是""、size>0 |
非空 | @NotBlank | CharSequence | No | 不是null、trim后长度大于0 |
非空 | @Null | 所有对象 | Yes | 是null |
长度 | @Size(min=0, max=Integer.MAX_VALUE) | CharSequence, Collection, Map, Array | Yes | 字符串长度、集合size |
大小 | @Positive | BigDecimal, BigInteger, byte, short, int, long, float, double | Yes | 数字>0 |
大小 | @PositiveOrZero | BigDecimal, BigInteger, byte, short, int, long, float, double | Yes | 数字>=0 |
大小 | @Negative | BigDecimal, BigInteger, byte, short, int, long, float, double | Yes | 数字<0 |
大小 | @NegativeOrZero | BigDecimal, BigInteger, byte, short, int, long, float, double | Yes | 数字<=0 |
大小 | @Min(value=0L) | BigDecimal, BigInteger, byte, short, int, long | Yes | 数字>=min.value |
大小 | @Max(value=0L) | BigDecimal, BigInteger, byte, short, int, long | Yes | 数字<=max.value |
大小 | @Range(min=0L, max=Long.MAX_VALUE) | BigDecimal, BigInteger, byte, short, int, long | Yes | range.min<=数字<=range.max |
大小 | @DecimalMin(value="") | BigDecimal, BigInteger, CharSequence, byte, short, int, long | Yes | 数字>=decimalMin.value |
大小 | @DecimalMax(value="") | BigDecimal, BigInteger, CharSequence, byte, short, int, long | Yes | 数字<=decimalMax.value |
日期 | @Past |
|
Yes | 时间在当前时间之前 |
日期 | @PastOrPresent | 同上 | Yes | 时间在当前时间之前 或者等于此时 |
日期 | @Future | 同上 | Yes | 时间在当前时间之后 |
日期 | @FutureOrPresent | 同上 | Yes | 时间在当前时间之后 或者等于此时 |
格式 | @Pattern(regexp="", flags={}) | CharSequence | Yes | 匹配正则表达式 |
格式 | @Email @Email(regexp=".*", flags={}) |
CharSequence | Yes | 匹配邮箱格式 |
格式 | @Digts(integer=0, fraction=0) | BigDecimal, BigInteger, CharSequence, byte, short, int, long | Yes | 必须是数字类型,且满足整数位数<=digits.integer, 浮点位数<=digits.fraction |
布尔 | @AssertTrue | boolean | Yes | 必须是true |
布尔 | @AssertFalse | boolean | Yes | 必须是false |
注: 后续还需补充Hibernate Validator中实现的constraints注解,如表中@Range。
对象集成constraints示例
/** * 用户 - DTO * * @author luohq * @date 2021-09-04 13:45 */ public class UserDto { @NotNull(groups = Update.class) @Positive private Long id; @NotBlank @Size(max = 32) private String name; @NotNull @Range(min = 1, max = 2) private Integer sex; @NotBlank @Pattern(regexp = "^\\d{8,11}$") private String phone; @NotNull @Email private String mail; @NotNull @Pattern(regexp = "^\\d{4}-\\d{2}-\\d{2}$") private String birthDateStr; @NotNull @PastOrPresent private LocalDate birthLocalDate; @NotNull @Past @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss") private LocalDateTime registerLocalDatetime; @Valid @NotEmpty private List<OrgDto> orgs; //省略getter、setter、toString方法 } /** * 组织 - DTO * * @author luohq * @date 2021-09-04 14:10 */ public class OrgDto { @NotNull @Positive private Long orgId; @NotBlank @Size(min = 1, max = 32) private String orgName; //省略getter、setter、toString方法 }
注:
- 可通过constraints注解的groups指定分组
即指定constraints仅在指定group生效,默认均为Default分组,
后续可通过@Validated({MyGroupInterface.class})形式进行分组的指定 - 可通过@Valid注解进行级联验证(Cascaded Validation,即嵌套对象验证)
如上示例中@Valid添加在 List<OrgDto> orgs上,即会对list中的每个OrgDto进行验证
SpringBoot集成自动验证
参考:
https://www.baeldung.com/javax-validation-method-constraints#validation
集成maven依赖
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-validation</artifactId> </dependency>
验证RequestBody、Form对象参数
在参数前加@Validated
验证简单参数
在controller类上加@Validated
验证指定分组
全局controller验证异常处理
通过@ControllerAdvice、@ExceptionHandler来对SpringBoot Validation验证框架抛出的异常进行统一处理,
并将错误信息拼接后统一返回,具体处理代码如下:
import com.luo.demo.validation.domain.result.CommonResult; import com.luo.demo.validation.enums.RespCodeEnum; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Value; import org.springframework.http.HttpStatus; import org.springframework.validation.BindException; import org.springframework.validation.FieldError; 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 javax.servlet.http.HttpServletRequest; import javax.validation.ConstraintViolationException; import java.util.List; import java.util.Optional; import java.util.stream.Collectors; import java.util.stream.Stream; /** * controller增强 - 通用异常处理 * * @author luohq * @date 2021-09-04 13:43 */ @ControllerAdvice public class ControllerAdviceHandler { private static final Logger log = LoggerFactory.getLogger(ControllerAdviceHandler.class); /** * 是否在响应结果中展示验证错误提示信息 */ @Value("${spring.validation.msg.enable:true}") private Boolean enableValidationMsg; /** * 符号常量 */ private final String DOT = "."; private final String SEPARATOR_COMMA = ", "; private final String SEPARATOR_COLON = ": "; /** * 验证异常处理 - 在@RequestBody上添加@Validated处触发 * * @param request * @param ex * @return */ @ExceptionHandler({MethodArgumentNotValidException.class}) @ResponseStatus(HttpStatus.OK) @ResponseBody public CommonResult handleMethodArgumentNotValidException(HttpServletRequest request, MethodArgumentNotValidException ex) { log.warn("{} - MethodArgumentNotValidException!", request.getServletPath()); CommonResult commonResult = CommonResult.respWith(RespCodeEnum.PARAM_INVALID.getCode(), this.convertFiledErrors(ex.getBindingResult().getFieldErrors())); log.warn("{} - resp with param invalid: {}", request.getServletPath(), commonResult); return commonResult; } /** * 验证异常处理 - form参数(对象参数,没有加@RequestBody)触发 * * @param request * @param ex * @return */ @ExceptionHandler({BindException.class}) @ResponseStatus(HttpStatus.OK) @ResponseBody public CommonResult handleBindException(HttpServletRequest request, BindException ex) { log.warn("{} - BindException!", request.getServletPath()); CommonResult commonResult = CommonResult.respWith(RespCodeEnum.PARAM_INVALID.getCode(), this.convertFiledErrors(ex.getFieldErrors())); log.warn("{} - resp with param invalid: {}", request.getServletPath(), commonResult); return commonResult; } /** * 验证异常处理 - @Validated加在controller类上, * 且在参数列表中直接指定constraints时触发 * * @param request * @param ex * @return */ @ExceptionHandler({ConstraintViolationException.class}) @ResponseStatus(HttpStatus.OK) @ResponseBody public CommonResult handleConstraintViolationException(HttpServletRequest request, ConstraintViolationException ex) { log.warn("{} - ConstraintViolationException - {}", request.getServletPath(), ex.getMessage()); CommonResult commonResult = CommonResult.respWith(RespCodeEnum.PARAM_INVALID.getCode(), this.convertConstraintViolations(ex)); log.warn("{} - resp with param invalid: {}", request.getServletPath(), commonResult); return commonResult; } /** * 全局默认异常处理 * * @param request * @param ex * @return */ @ExceptionHandler({Throwable.class}) @ResponseStatus(HttpStatus.OK) @ResponseBody public CommonResult handleException(HttpServletRequest request, Throwable ex) { log.warn("{} - Exception!", request.getServletPath(), ex); CommonResult commonResult = CommonResult.failed(); log.warn("{} - resp failed: {}", request.getServletPath(), commonResult); return commonResult; } /** * 转换FieldError列表为错误提示信息 * * @param fieldErrors * @return */ private String convertFiledErrors(List<FieldError> fieldErrors) { return Optional.ofNullable(fieldErrors) .filter(fieldErrorsInner -> this.enableValidationMsg) .map(fieldErrorsInner -> fieldErrorsInner.stream() .flatMap(fieldError -> Stream.of(fieldError.getField(), SEPARATOR_COLON, fieldError.getDefaultMessage(), SEPARATOR_COMMA)) .collect(Collectors.joining())) .map(msg -> msg.substring(0, msg.length() - SEPARATOR_COMMA.length())) .orElse(null); } /** * 转换ConstraintViolationException异常为错误提示信息 * * @param constraintViolationException * @return */ private String convertConstraintViolations(ConstraintViolationException constraintViolationException) { return Optional.ofNullable(constraintViolationException.getConstraintViolations()) .filter(constraintViolations -> this.enableValidationMsg) .map(constraintViolations -> constraintViolations.stream() .flatMap(constraintViolation -> { String path = constraintViolation.getPropertyPath().toString(); path = path.substring(path.lastIndexOf(DOT) + 1); String errMsg = constraintViolation.getMessage(); return Stream.of(path, SEPARATOR_COLON, errMsg, SEPARATOR_COMMA); }).collect(Collectors.joining()) ).map(msg -> msg.substring(0, msg.length() - SEPARATOR_COMMA.length())) .orElse(null); } }
参数验证未通过返回结果示例:
注: 其中CommonResult为统一返回结果,可根据自己业务进行调整
自定义constraints
自定义field constraint注解主要分为以下几步:
(1)定义constraint annotation注解及其属性
(2)通过注解的元注解@Constraint(validatedBy = {})关联的具体的验证器实现
(3)实现验证器逻辑
@DateFormat
具体字符串日期格式constraint @DateFormat定义示例如下:
import javax.validation.Constraint; import javax.validation.Payload; import java.lang.annotation.*; import static java.lang.annotation.ElementType.ANNOTATION_TYPE; /** * The annotated {@code CharSequence} must match date format. * The default date format is "yyyy-MM-dd". * Can override with property "format". * see {@link java.time.format.DateTimeFormatter}. * <p> * Accepts {@code CharSequence}. {@code null} elements are considered valid. * * @author luo * @date 2021-09-05 */ @Documented @Constraint(validatedBy = DateFormatValidator.class) @Target({ElementType.METHOD, ElementType.FIELD, ANNOTATION_TYPE,}) @Retention(RetentionPolicy.RUNTIME) public @interface DateFormat { String message() default "日期格式不正确"; String format() default "yyyy-MM-dd"; Class<?>[] groups() default {}; Class<? extends Payload>[] payload() default {}; } import org.springframework.util.StringUtils; import javax.validation.ConstraintValidator; import javax.validation.ConstraintValidatorContext; import java.time.format.DateTimeFormatter; /** * Date Format validator * * @author luohq * @date 2021-09-05 */ public class DateFormatValidator implements ConstraintValidator<DateFormat, String> { private String format; @Override public void initialize(DateFormat dateFormat) { this.format = dateFormat.format(); } @Override public boolean isValid(String dateStr, ConstraintValidatorContext cxt) { if (!StringUtils.hasText(dateStr)) { return true; } try { DateTimeFormatter.ofPattern(this.format).parse(dateStr); return true; } catch (Throwable ex) { return false; } } }
@PhoneNo
在查看hbernate-validator中URL、Email约束实现时,发现可以通过元注解的形式去复用constraint实现(如@Pattern),故参考如上方式实现@PhoneNo约束
import javax.validation.Constraint; import javax.validation.OverridesAttribute; import javax.validation.Payload; import javax.validation.ReportAsSingleViolation; import javax.validation.constraints.Pattern; import java.lang.annotation.Documented; import java.lang.annotation.Repeatable; import java.lang.annotation.Retention; import java.lang.annotation.Target; import static java.lang.annotation.ElementType.*; import static java.lang.annotation.RetentionPolicy.RUNTIME; /** * The annotated {@code CharSequence} must match phone no format. * The regular expression follows the Java regular expression conventions * see {@link java.util.regex.Pattern}. * <p> * Accepts {@code CharSequence}. {@code null} elements are considered valid. * * @author luo * @date 2021-09-05 */ @Documented @Constraint(validatedBy = {}) @Target({METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER, TYPE_USE}) @Retention(RUNTIME) @Repeatable(PhoneNo.List.class) @ReportAsSingleViolation @Pattern(regexp = "") public @interface PhoneNo { String message() default "电话号码格式不正确"; Class<?>[] groups() default {}; Class<? extends Payload>[] payload() default {}; /** * @return an additional regular expression the annotated PhoneNo must match. The default is "^\\d{8,11}$" */ @OverridesAttribute(constraint = Pattern.class, name = "regexp") String regexp() default "^\\d{8,11}$"; /** * @return used in combination with {@link #regexp()} in order to specify a regular expression option */ @OverridesAttribute(constraint = Pattern.class, name = "flags") Pattern.Flag[] flags() default {}; /** * Defines several {@code @URL} annotations on the same element. */ @Target({METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER, TYPE_USE}) @Retention(RUNTIME) @Documented @interface List { PhoneNo[] value(); } }
注: 同理可以实现@IdNo约束
使用自定义constraint注解
可将之前的对象集成示例中代码调整为使用自定义验证注解如下:
/** * 用户 - DTO * * @author luohq * @date 2021-09-04 13:45 */ public class UserDto { ... @NotBlank //@Pattern(regexp = "^\\d{8,11}$") @PhoneNo private String phone; @NotBlank @IdNo private String idNo; @NotNull //@Pattern(regexp = "^\\d{4}-\\d{2}-\\d{2}$") @DateFormat //@DateTimeFormat private String birthDateStr; ... }
同时自定义constraints还支持跨多参数、验证对象里的多个field、验证返回对象等用法,待后续再详细探索。
问题
通过在对象属性、方法参数上标注注解的形式,需要侵入代码,之前有的架构师不喜欢这种风格。
在一方开发时,我们有全部源码且在公司内部,这种方式还是可以的,且集成比较方便,
但是依赖三方Api jar包(参数对象定义在jar包中),我们无法直接去修改参数对象,依旧使用这种侵入代码的注解方式就不适用了,
针对三方包、或者替代注解这种形式,之前公司内部有实现过基于xml配置的形式进行验证,
这种方式不侵入参数对象,且集成也还算方便,
但是用起来还是没有直接在代码里写注解来的顺手(代码有补全、有提示、程序员友好),
所以一方开发时,首选推荐SpringBoot Validation这套体系,无法直接编辑参数对象时再考虑其他方式。
参考:
【自定义validator - field、class level】https://www.baeldung.com/spring-mvc-custom-validator
【Spring boot集成validation、全局异常处理】https://www.baeldung.com/spring-boot-bean-validation
【JSR380、非Spring框架集成validation】https://www.baeldung.com/javax-validation
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