我正在尝试结合使用 JSR-303 Bean Validation API 和 Spring's Validator 为 spring boot 端点实现一些自定义验证逻辑。

根据 Validator 类图，似乎可以扩展 CustomValidatorBean、SpringValidatorAdapter 或 LocalValidatorFactoryBean 之一以添加一些自定义验证逻辑进入重写方法 validate(Object target, Errors errors)。

.

但是，如果我创建一个 validator 扩展这三个类中的任何一个并使用 @InitBinder 注册它，它的 validate(Object target, Errors errors) 方法永远不会被调用并且不执行验证。如果我删除 @InitBinder，则默认的 spring validator 会执行 JSR-303 Bean Validation。

休息 Controller :

@RestController
public class PersonEndpoint {

    @InitBinder("person")
    protected void initBinder(WebDataBinder binder) {
        binder.setValidator(new PersonValidator());
    }

    @RequestMapping(path = "/person", method = RequestMethod.PUT)
    public ResponseEntity<Person> add(@Valid @RequestBody Person person) {

        person = personService.save(person);
        return ResponseEntity.ok().body(person);
    }
}

自定义 validator :

public class PersonValidator extends CustomValidatorBean {

    @Override
    public boolean supports(Class<?> clazz) {
        return Person.class.isAssignableFrom(clazz);
    }

    @Override
    public void validate(Object target, Errors errors) {
        super.validate(target, errors);
        System.out.println("PersonValidator.validate() target="+ target +" errors="+ errors);
    }

}

如果我的 validator 实现了 org.springframework.validation.Validator 然后它的 validate(Object target, Errors errors) 方法被调用但是 JSR-303 Bean Validation 不在它之前执行。我可以实现我的自定义 JSR-303 验证，类似于 SpringValidatorAdapter 实现其 JSR-303 Bean Validation 的方式，但必须有一种方法来扩展它:

    @Override
    public void validate(Object target, Errors errors) {
        if (this.targetValidator != null) {
            processConstraintViolations(this.targetValidator.validate(target), errors);
        }
    }

我研究过使用自定义 JSR-303 约束来避免一起使用 org.springframework.validation.Validator 但必须有一种方法可以使自定义 validator 工作。

Spring validation documentation将两者结合起来不是很清楚:

An application can also register additional Spring Validator instances per DataBinder instance, as described in Section 9.8.3, “Configuring a DataBinder”. This may be useful for plugging in validation logic without the use of annotations.

稍后会涉及配置多个 validator 实例

A DataBinder can also be configured with multiple Validator instances via dataBinder.addValidators and dataBinder.replaceValidators. This is useful when combining globally configured Bean Validation with a Spring Validator configured locally on a DataBinder instance. See ???.

我正在使用 spring boot 1.4.0。

最佳答案

这个问题可以通过扩展 LocalValidatorFactoryBean 来解决，您可以覆盖此类中的 validate 方法，以提供您想要的任何行为。

在我的例子中，我需要在同一个 Controller 的不同方法中为同一个模型使用 JSR-303 和自定义 validator ，通常建议使用@InitBinder，但这对我的例子来说是不够的，因为 InitBinder 在模型和 validator (如果您使用@RequestBody InitBinder 仅适用于一个模型和每个 Controller 一个 validator )。

Controller

@RestController
public class LoginController {

    @PostMapping("/test")
    public Test test(@Validated(TestValidator.class) @RequestBody Test test) {
        return test;
    }

    @PostMapping("/test2")
    public Test test2(@Validated @RequestBody Test test) {
        return test;
    }
}

自定义 validator

public class TestValidator implements org.springframework.validation.Validator {

    @Override
    public boolean supports(Class<?> clazz) {
        return Test.class.isAssignableFrom(clazz);
    }

    @Override
    public void validate(Object target, Errors errors) {
        Test test = (Test) target;
        errors.rejectValue("field3", "weird");
        System.out.println(test.getField1());
        System.out.println(test.getField2());
        System.out.println(test.getField3());
     }
}

要验证的类

public class Test {

    @Size(min = 3)
    private String field2;

    @NotNull
    @NotEmpty
    private String field1;

    @NotNull
    @Past
    private LocalDateTime field3;

    //...
    //getter/setter
    //...
}

CustomLocalValidatorFactoryBean

public class CustomLocalValidatorFactoryBean extends LocalValidatorFactoryBean {

    private Logger logger = LoggerFactory.getLogger(this.getClass());

    @Override
    public void validate(@Nullable Object target, Errors errors, @Nullable Object... validationHints) {
        Set<Validator> concreteValidators = new LinkedHashSet<>();
        Set<Class<?>> interfaceGroups = new LinkedHashSet<>();
        extractConcreteValidatorsAndInterfaceGroups(concreteValidators, interfaceGroups, validationHints);
        proccessConcreteValidators(target, errors, concreteValidators);
        processConstraintViolations(super.validate(target, interfaceGroups.toArray(new Class<?>[interfaceGroups.size()])), errors);
    }

    private void proccessConcreteValidators(Object target, Errors errors, Set<Validator> concreteValidators) {
        for (Validator validator : concreteValidators) {
            validator.validate(target, errors);
        }
    }

    private void extractConcreteValidatorsAndInterfaceGroups(Set<Validator> concreteValidators, Set<Class<?>> groups, Object... validationHints) {
        if (validationHints != null) {
            for (Object hint : validationHints) {
                if (hint instanceof Class) {
                    if (((Class<?>) hint).isInterface()) {
                        groups.add((Class<?>) hint);
                    } else {
                        Optional<Validator> validatorOptional = getValidatorFromGenericClass(hint);
                        if (validatorOptional.isPresent()) {
                            concreteValidators.add(validatorOptional.get());
                        }
                    }
                }
            }
        }
    }

    @SuppressWarnings("unchecked")
    private Optional<Validator> getValidatorFromGenericClass(Object hint) {
        try {
            Class<Validator> clazz = (Class<Validator>) Class.forName(((Class<?>) hint).getName());
            return Optional.of(clazz.newInstance());
        } catch (ClassNotFoundException | InstantiationException | IllegalAccessException e) {
            logger.info("There is a problem with the class that you passed to "
                    + " @Validated annotation in the controller, we tried to "
                    + " cast to org.springframework.validation.Validator and we cant do this");
        }
        return Optional.empty();
    }

}

配置应用

@SpringBootApplication
public class Application {

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

    @Bean
    public javax.validation.Validator localValidatorFactoryBean() {
        return new CustomLocalValidatorFactoryBean();
    }
}

/test端点的输入:

{
    "field1": "",
    "field2": "aaaa",
    "field3": "2018-04-15T15:10:24"
}

/test 端点的输出:

{
    "timestamp": "2018-04-16T17:34:28.532+0000",
    "status": 400,
    "error": "Bad Request",
    "errors": [
        {
            "codes": [
                "weird.test.field3",
                "weird.field3",
                "weird.java.time.LocalDateTime",
                "weird"
            ],
            "arguments": null,
            "defaultMessage": null,
            "objectName": "test",
            "field": "field3",
            "rejectedValue": "2018-04-15T15:10:24",
            "bindingFailure": false,
            "code": "weird"
        },
        {
            "codes": [
                "NotEmpty.test.field1",
                "NotEmpty.field1",
                "NotEmpty.java.lang.String",
                "NotEmpty"
            ],
            "arguments": [
                {
                    "codes": [
                        "test.field1",
                        "field1"
                    ],
                    "arguments": null,
                    "defaultMessage": "field1",
                    "code": "field1"
                }
            ],
            "defaultMessage": "Não pode estar vazio",
            "objectName": "test",
            "field": "field1",
            "rejectedValue": "",
            "bindingFailure": false,
            "code": "NotEmpty"
        }
    ],
    "message": "Validation failed for object='test'. Error count: 2",
    "path": "/user/test"
}

输入到/test2端点:

{
    "field1": "",
    "field2": "aaaa",
    "field3": "2018-04-15T15:10:24"
}

输出到/test2端点:

{
    "timestamp": "2018-04-16T17:37:30.889+0000",
    "status": 400,
    "error": "Bad Request",
    "errors": [
        {
            "codes": [
                "NotEmpty.test.field1",
                "NotEmpty.field1",
                "NotEmpty.java.lang.String",
                "NotEmpty"
            ],
            "arguments": [
                {
                    "codes": [
                        "test.field1",
                        "field1"
                    ],
                    "arguments": null,
                    "defaultMessage": "field1",
                    "code": "field1"
                }
            ],
            "defaultMessage": "Não pode estar vazio",
            "objectName": "test",
            "field": "field1",
            "rejectedValue": "",
            "bindingFailure": false,
            "code": "NotEmpty"
        }
    ],
    "message": "Validation failed for object='test'. Error count: 1",
    "path": "/user/test2"
}

希望对您有所帮助。

关于java - 使用 JSR-303 和 Spring 的 validator 的组合为 spring boot 端点实现自定义验证逻辑，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/39001106/