Spring MVC - 自动查找验证器

假设我有一个像这样的示例实体类：

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：

@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，如果我省略验证器注册部分（即以下内容），则不会执行验证。

@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？

这是一个基于 Spring Boot 的应用程序。

你可以使用我的例子gist https://gist.github.com/pyanoveugen/feb4188719adcfd0bf248d0f113b4fdd或以下。我们的想法是拥有一个主 CompositeValidator，它将成为所有 Validator 或 SmartValidator 实例的持有者。

它支持提示，还可以与 Hibernate Annotation Validator (LocalValidatorFactoryBean) 集成。而且每个特定模型也可以有多个验证器。

复合验证器.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);
                }
            }
        }
    }
}

一些控制器.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;
                }
            }
        }

或者 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>