Spring MVC-自动查找验证器 [英] Spring MVC - lookup validators automatically

问题描述

假设我有一个这样的示例实体类:

Suppose I have a sample entity class like this:

public class Address {
    ...
}

和相应的验证器:

@Component
public AddressValidator implements Validator {

    @Override
    public boolean supports(Class<?> entityClass) {
        return entityClass.equals(Address.class);
    }

    @Override
    public void validate(Object obj, Errors errors) {
        ...
    }
}

当我使用如下所示的控制器时，一切正常:

When I use a controller like the following, everything works:

@RestController
@RequestMapping("/addresses")
public class AddressController {

    @Autowired
    private AddressValidator validator;

    @InitBinder
    protected void initBinder(WebDataBinder binder) {
        binder.setValidator(validator);
    }

    @RequestMapping(method=POST)
    public Long addNewAddress(@Valid @RequestBody Address address) {
        ...
    }
}

但是，如果我省略了验证器注册部分(即以下内容)，则不会执行验证.

However, if I omit the validator registering part (i.e. the following), validation is not performed.

@Autowired
private AddressValidator validator;

@InitBinder
protected void initBinder(WebDataBinder binder) {
    binder.setValidator(validator);
}

必须手动注册验证器似乎毫无意义.我可以指示Spring自动查找验证器(类似于查找控制器的方式)吗?

Having to register validators manually seems pointless. Can I instruct Spring to look up validators automatically (similar to how controllers are looked up)?

这是一个基于Spring Boot的应用程序.

It's a Spring Boot based application.

推荐答案

您可以从要点或以下.这个想法是要有一个主要的CompositeValidator，它将成为您所有Validator或SmartValidator实例的所有者.

You can use my example from gist or below. The idea is to have a main CompositeValidator that will be a holder of all your Validator or SmartValidator instances.

它支持提示，还可以与Hibernate Annotation Validator(LocalValidatorFactoryBean)集成.每个特定模型也可能有一个以上的验证器.

It supports hints and can be also integrate with Hibernate Annotation Validator (LocalValidatorFactoryBean). And also it's possible to have more that one validator per specific Model.

CompositeValidator.java

@Component
public class CompositeValidator implements SmartValidator {
    @Autowired
    private List<Validator> validators = Collections.emptyList();

    @PostConstruct
    public void init() {
        Collections.sort(validators, AnnotationAwareOrderComparator.INSTANCE);
    }

    @Override
    public boolean supports(Class<?> clazz) {
         for (Validator validator : validators) {
            if (validator.supports(clazz)) {
                return true;
            }
        }
        return false;
    }

    @Override
    public void validate(Object target, Errors errors) {
        validate(target, errors, javax.validation.groups.Default.class);
    }

    @Override
    public void validate(Object target, Errors errors, Object... validationHints) {
        Class<?> clazz = target.getClass();

        for (Validator validator : validators) {
            if (validator.supports(clazz)) {
                if (validator instanceof SmartValidator) {
                    ((SmartValidator) validator).validate(target, errors, validationHints);
                } else {
                    validator.validate(target, errors);
                }
            }
        }
    }
}

SomeController.java

@Controller
@RequestMapping("/my/resources")
public class SomeController {

    @RequestMapping(method = RequestMethod.POST)
    public Object save(
            @Validated(javax.validation.groups.Default.class) // this interface descriptor (class) is used by default
            @RequestBody MyResource myResource
    ) { return null; }
}

Java配置

 @Configuration
    public class WebConfig {
        /** used for Annotation based validation, it can be created by spring automaticaly and you don't do it manualy */
        // @Bean
        // public Validator jsr303Validator() {
        //   LocalValidatorFactoryBean validator = new LocalValidatorFactoryBean();
        //   // validator.setValidationMessageSource(...);
        //   return validator;
        // }

        @Bean
        public WebMvcConfigurerAdapter webMvcConfigurerAdapter() {
            return new WebMvcConfigurerAdapter() {
                @Autowired
                private CompositeValidator validator;

                @Override
                public Validator getValidator() {
                    return validator;
                }
            }
        }

或XML配置

<!-- used for Annotation based validation, it can be created by spring automaticaly and you don't do it manualy -->
<!--<bean id="jsr303Validator" class="org.springframework.validation.beanvalidation.LocalValidatorFactoryBean">-->
<!--  <property name="validationMessageSource" ref="messageSource"/>-->
<!--</bean>-->

<mvc:annotation-driven validator="compositeValidator">
  //...
</mvc:annotation-driven>

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