高效使用hibernate-validator校驗框架

一、前言

　　高效、合理的使用hibernate-validator校驗框架可以提高程序的可讀性，以及減少不必要的代碼邏輯。接下來會介紹一下常用一些使用方式。

二、常用注解說明

限制	說明
@Null	限制只能為null
@NotNull	限制必須不為null
@AssertFalse	限制必須為false
@AssertTrue	限制必須為true
@DecimalMax(value)	限制必須為一個不大于指定值的數字
@DecimalMin(value)	限制必須為一個不小于指定值的數字
@Digits(integer,fraction)	限制必須為一個小數，且整數部分的位數不能超過integer，小數部分的位數不能超過fraction
@Future	限制必須是一個將來的日期
@Max(value)	限制必須為一個不大于指定值的數字
@Min(value)	限制必須為一個不小于指定值的數字
@Past	限制必須是一個過去的日期
@Pattern(value)	限制必須符合指定的正則表達式
@Size(max,min)	限制字符長度必須在min到max之間
@Past	驗證注解的元素值（日期類型）比當前時間早
@NotEmpty	驗證注解的元素值不為null且不為空（字符串長度不為0、集合大小不為0）
@NotBlank	驗證注解的元素值不為空（不為null、去除首位空格后長度為0），不同于@NotEmpty，@NotBlank只應用于字符串且在比較時會去除字符串的空格
@Email	驗證注解的元素值是Email，也可以通過正則表達式和flag指定自定義的email格式

三、定義校驗分組

public class ValidateGroup {public interface FirstGroup {}public interface SecondeGroup {}public interface ThirdGroup {}
}

四、定義校驗Bean

@Validated
@GroupSequence({ValidateGroup.FirstGroup.class, BaseMessageRequestBean.class})
public class BaseMessageRequestBean {//渠道類型@NotNull(message = "channelType為NULL", groups = ValidateGroup.FirstGroup.class)private String channelType;//消息（模板消息或者普通消息）@NotNull(message = "data為NUll", groups = ValidateGroup.FirstGroup.class)
    @Validprivate Object data;//業務類型@NotNull(message = "bizType為NULL", groups = ValidateGroup.FirstGroup.class)private String bizType;//消息推送對象@NotBlank(message = "toUser為BLANK", groups = ValidateGroup.FirstGroup.class)private String toUser;private long createTime = Instant.now().getEpochSecond();......
}

　　請自行參考：@Validated和@Valid區別

五、validator基本使用

@RestController
public class TestValidatorController {@RequestMapping("/test/validator")public void test(@Validated BaseMessageRequestBean bean){
        ...}
}

　　這種使用方式有一個弊端，不能自定義返回異常。spring如果驗證失敗，則直接拋出異常，一般不可控。

六、借助BindingResult

@RestController
public class TestValidatorController {@RequestMapping("/test/validator")public void test(@Validated BaseMessageRequestBean bean, BindingResult result){result.getAllErrors();...}
}

　　如果方法中有BindingResult類型的參數，spring校驗完成之后會將校驗結果傳給這個參數。通過BindingResult控制程序拋出自定義類型的異常或者返回不同結果。

七、全局攔截校驗器

　　當然了，需要在借助BindingResult的前提下...

@Aspect
@Component
public class ControllerValidatorAspect {@Around("execution(* com.*.controller..*.*(..)) && args(..,result)")public Object doAround(ProceedingJoinPoint pjp, result result) {result.getFieldErrors();...}
}

　　這種方式可以減少controller層校驗的代碼，校驗邏輯統一處理，更高效。

?八、借助ValidatorUtils工具類

@Bean
public Validator validator() {return new LocalValidatorFactoryBean();
}

LocalValidatorFactoryBean官方示意

　　LocalValidatorFactoryBean是Spring應用程序上下文中javax.validation（JSR-303）設置的中心類：它引導javax.validation.ValidationFactory并通過Spring Validator接口以及JSR-303 Validator接口和ValidatorFactory公開它。界面本身。通過Spring或JSR-303 Validator接口與該bean的實例進行通信時，您將與底層ValidatorFactory的默認Validator進行通信。這非常方便，因為您不必在工廠執行另一個調用，假設您幾乎總是會使用默認的Validator。這也可以直接注入Validator類型的任何目標依賴項！從Spring 5.0開始，這個類需要Bean Validation 1.1+，特別支持Hibernate Validator 5.x（參見setValidationMessageSource（org.springframework.context.MessageSource））。這個類也與Bean Validation 2.0和Hibernate Validator 6.0運行時兼容，有一個特別說明：如果你想調用BV 2.0的getClockProvider（）方法，通過#unwrap（ValidatorFactory.class）獲取本機ValidatorFactory，在那里調用返回的本機引用上的getClockProvider（）方法。Spring的MVC配置命名空間也使用此類，如果存在javax.validation API但未配置顯式Validator。

@Component
public class ValidatorUtils implements ApplicationContextAware {@Overridepublic void setApplicationContext(ApplicationContext applicationContext) throws BeansException {ValidatorUtils.validator = (Validator) applicationContext.getBean("validator");}private static Validator validator;public static Optional<String> validateResultProcess(Object obj)  {Set<ConstraintViolation<Object>> results = validator.validate(obj);if (CollectionUtils.isEmpty(results)) {return Optional.empty();}StringBuilder sb = new StringBuilder();for (Iterator<ConstraintViolation<Object>> iterator = results.iterator(); iterator.hasNext(); ) {sb.append(iterator.next().getMessage());if (iterator.hasNext()) {sb.append(" ,");}}return Optional.of(sb.toString());}
}

　　為什么要使用這個工具類呢？

　　1、controller方法中不用加入BindingResult參數

　　2、controller方法中需要校驗的參數也不需要加入@Valid或者@Validated注解

　　怎么樣是不是又省去了好多代碼，開不開心。

　　具體使用，在controller方法或者全局攔截校驗器中調用?ValidatorUtils.validateResultProcess(需要校驗的Bean) 直接獲取校驗的結果。

　　請參考更多功能的ValidatorUtils工具類。

九、自定義校驗器

　　定義一個MessageRequestBean，繼承BaseMessageRequestBean，signature字段需要我們自定義校驗邏輯。

@Validated
@GroupSequence({ValidateGroup.FirstGroup.class, ValidateGroup.SecondeGroup.class, MessageRequestBean.class})
@LogicValidate(groups = ValidateGroup.SecondeGroup.class)
public class MessageRequestBean extends BaseMessageRequestBean {//簽名信息（除該字段外的其他字段按照字典序排序，將值順序拼接在一起，進行md5+Base64簽名算法）@NotBlank(message = "signature為BLANK", groups = ValidateGroup.FirstGroup.class)private String signature;...
}

　　實現自定義校驗邏輯也很簡單......

　　1、自定義一個帶有 @Constraint注解的注解@LogicValidate，validatedBy 屬性指向該注解對應的自定義校驗器

@Target({TYPE})
@Retention(RUNTIME)
//指定驗證器  
@Constraint(validatedBy = LogicValidator.class)
@Documented
public @interface LogicValidate {String message() default "校驗異常";//分組Class<?>[] groups() default {};Class<? extends Payload>[] payload() default {};
}

　　2、自定義校驗器LogicValidator，泛型要關聯上自定義的注解和需要校驗bean的類型

public class LogicValidator implements ConstraintValidator<LogicValidate, MessageRequestBean> {@Overridepublic void initialize(LogicValidate logicValidate) {}@Overridepublic boolean isValid(MessageRequestBean messageRequestBean, ConstraintValidatorContext context) {String toSignature = StringUtils.join( messageRequestBean.getBizType(), messageRequestBean.getChannelType(), messageRequestBean.getData(), messageRequestBean.getToUser());String signature = new Base64().encodeAsString(DigestUtils.md5(toSignature));if (!messageRequestBean.getSignature().equals(signature)) {context.disableDefaultConstraintViolation();context.buildConstraintViolationWithTemplate("signature校驗失敗").addConstraintViolation();return false;}return true;}
}

　　可以通過ConstraintValidatorContext禁用掉默認的校驗配置，然后自定義校驗配置，比如校驗失敗后返回的信息。

十、springboot國際化信息配置

@Configuration
@ConditionalOnMissingBean(value = MessageSource.class, search = SearchStrategy.CURRENT)
@AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE)
@Conditional(ResourceBundleCondition.class)
@EnableConfigurationProperties
@ConfigurationProperties(prefix = "spring.messages")
public class MessageSourceAutoConfiguration {private static final Resource[] NO_RESOURCES = {};/*** Comma-separated list of basenames, each following the ResourceBundle convention.* Essentially a fully-qualified classpath location. If it doesn't contain a package* qualifier (such as "org.mypackage"), it will be resolved from the classpath root.*/private String basename = "messages";/*** Message bundles encoding.*/private Charset encoding = Charset.forName("UTF-8");/*** Loaded resource bundle files cache expiration, in seconds. When set to -1, bundles* are cached forever.*/private int cacheSeconds = -1;/*** Set whether to fall back to the system Locale if no files for a specific Locale* have been found. if this is turned off, the only fallback will be the default file* (e.g. "messages.properties" for basename "messages").*/private boolean fallbackToSystemLocale = true;/*** Set whether to always apply the MessageFormat rules, parsing even messages without* arguments.*/private boolean alwaysUseMessageFormat = false;@Beanpublic MessageSource messageSource() {ResourceBundleMessageSource messageSource = new ResourceBundleMessageSource();if (StringUtils.hasText(this.basename)) {messageSource.setBasenames(StringUtils.commaDelimitedListToStringArray(StringUtils.trimAllWhitespace(this.basename)));}if (this.encoding != null) {messageSource.setDefaultEncoding(this.encoding.name());}messageSource.setFallbackToSystemLocale(this.fallbackToSystemLocale);messageSource.setCacheSeconds(this.cacheSeconds);messageSource.setAlwaysUseMessageFormat(this.alwaysUseMessageFormat);return messageSource;}public String getBasename() {return this.basename;}public void setBasename(String basename) {this.basename = basename;}public Charset getEncoding() {return this.encoding;}public void setEncoding(Charset encoding) {this.encoding = encoding;}public int getCacheSeconds() {return this.cacheSeconds;}public void setCacheSeconds(int cacheSeconds) {this.cacheSeconds = cacheSeconds;}public boolean isFallbackToSystemLocale() {return this.fallbackToSystemLocale;}public void setFallbackToSystemLocale(boolean fallbackToSystemLocale) {this.fallbackToSystemLocale = fallbackToSystemLocale;}public boolean isAlwaysUseMessageFormat() {return this.alwaysUseMessageFormat;}public void setAlwaysUseMessageFormat(boolean alwaysUseMessageFormat) {this.alwaysUseMessageFormat = alwaysUseMessageFormat;}protected static class ResourceBundleCondition extends SpringBootCondition {private static ConcurrentReferenceHashMap<String, ConditionOutcome> cache = new ConcurrentReferenceHashMap<String, ConditionOutcome>();@Overridepublic ConditionOutcome getMatchOutcome(ConditionContext context,AnnotatedTypeMetadata metadata) {String basename = context.getEnvironment().getProperty("spring.messages.basename", "messages");ConditionOutcome outcome = cache.get(basename);if (outcome == null) {outcome = getMatchOutcomeForBasename(context, basename);cache.put(basename, outcome);}return outcome;}private ConditionOutcome getMatchOutcomeForBasename(ConditionContext context,String basename) {ConditionMessage.Builder message = ConditionMessage.forCondition("ResourceBundle");for (String name : StringUtils.commaDelimitedListToStringArray(StringUtils.trimAllWhitespace(basename))) {for (Resource resource : getResources(context.getClassLoader(), name)) {if (resource.exists()) {return ConditionOutcome.match(message.found("bundle").items(resource));}}}return ConditionOutcome.noMatch(message.didNotFind("bundle with basename " + basename).atAll());}private Resource[] getResources(ClassLoader classLoader, String name) {try {return new PathMatchingResourcePatternResolver(classLoader).getResources("classpath*:" + name + ".properties");}catch (Exception ex) {return NO_RESOURCES;}}}}