Spring Boot：请求参数中的自定义验证

Question

我想验证我的控制器中的请求参数之一。请求参数应来自给定值列表之一，如果不是，则应引发错误。在下面的代码中，我希望请求参数 orderBy 来自 @ValuesAllowed 中存在的值列表。

@RestController
@RequestMapping("/api/opportunity")
@Api(value = "Opportunity APIs")
@ValuesAllowed(propName = "orderBy", values = { "OpportunityCount", "OpportunityPublishedCount", "ApplicationCount",
        "ApplicationsApprovedCount" })
public class OpportunityController {

@GetMapping("/vendors/list")
    @ApiOperation(value = "Get all vendors")

    public ResultWrapperDTO getVendorpage(@RequestParam(required = false) String term,
            @RequestParam(required = false) Integer page, @RequestParam(required = false) Integer size,
            @RequestParam(required = false) String orderBy, @RequestParam(required = false) String sortDir) {

我编写了一个自定义 bean 验证器，但不知何故这不起作用。即使为查询参数传递任何随机值，它也不会验证并引发错误。

@Repeatable(ValuesAllowedMultiple.class)
@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = {ValuesAllowedValidator.class})
public @interface ValuesAllowed {

    String message() default "Field value should be from list of ";
    Class<?>[] groups() default {};
    Class<? extends Payload>[] payload() default {};

    String propName();
    String[] values();
}

public class ValuesAllowedValidator implements ConstraintValidator<ValuesAllowed, Object> {

    private String propName;
    private String message;
    private String[] values;

    @Override
    public void initialize(ValuesAllowed requiredIfChecked) {
        propName = requiredIfChecked.propName();
        message = requiredIfChecked.message();
        values = requiredIfChecked.values();
    }

    @Override
    public boolean isValid(Object object, ConstraintValidatorContext context) {
        Boolean valid = true;
        try {
            Object checkedValue = BeanUtils.getProperty(object, propName);

            if (checkedValue != null) {
                valid = Arrays.asList(values).contains(checkedValue.toString().toLowerCase());
            } 

            if (!valid) {
                context.disableDefaultConstraintViolation();
                context.buildConstraintViolationWithTemplate(message.concat(Arrays.toString(values)))
                        .addPropertyNode(propName).addConstraintViolation();
            }
        } catch (IllegalAccessException e) {
            log.error("Accessor method is not available for class : {}, exception : {}", object.getClass().getName(), e);
            return false;
        } catch (NoSuchMethodException e) {
            log.error("Field or method is not present on class : {}, exception : {}", object.getClass().getName(), e);
            return false;
        } catch (InvocationTargetException e) {
            log.error("An exception occurred while accessing class : {}, exception : {}", object.getClass().getName(), e);
            return false;
        }
        return valid;
    }
}

Answer 1

案例1：如果ValuesAllowed注解根本没有被触发，可能是因为控制器没有使用@Validated注解。

@Validated
@ValuesAllowed(propName = "orderBy", values = { "OpportunityCount", "OpportunityPublishedCount", "ApplicationCount", "ApplicationsApprovedCount" })
public class OpportunityController {
@GetMapping("/vendors/list")
public String getVendorpage(@RequestParam(required = false) String term,..{
}

情况2：如果触发并抛出错误，可能是因为BeanUtils.getProperty没有解析属性并抛出异常。

如果上述解决方案不起作用，您可以尝试将注解移至方法级别并更新 Validator 以使用 OrderBy 参数的有效值列表。这对我有用。下面是示例代码。

@RestController
@RequestMapping("/api/opportunity")
@Validated
public class OpportunityController {
    @GetMapping("/vendors/list")
    public String getVendorpage(@RequestParam(required = false) String term,
            @RequestParam(required = false) Integer page, @RequestParam(required = false) Integer size,
            @ValuesAllowed(propName = "orderBy", values = { "OpportunityCount", "OpportunityPublishedCount", "ApplicationCount",
                    "ApplicationsApprovedCount" }) @RequestParam(required = false) String orderBy, @RequestParam(required = false) String sortDir) {
        return "success";
    }

@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = { ValuesAllowed.Validator.class })
public @interface ValuesAllowed {

    String message() default "Field value should be from list of ";

    Class<?>[] groups() default {};

    Class<? extends Payload>[] payload() default {};

    String propName();

    String[] values();

    class Validator implements ConstraintValidator<ValuesAllowed, String> {
        private String propName;
        private String message;
        private List<String> allowable;

        @Override
        public void initialize(ValuesAllowed requiredIfChecked) {
            this.propName = requiredIfChecked.propName();
            this.message = requiredIfChecked.message();
            this.allowable = Arrays.asList(requiredIfChecked.values());
        }

        public boolean isValid(String value, ConstraintValidatorContext context) {
            Boolean valid = value == null || this.allowable.contains(value);

            if (!valid) {
                context.disableDefaultConstraintViolation();
                context.buildConstraintViolationWithTemplate(message.concat(this.allowable.toString()))
                        .addPropertyNode(this.propName).addConstraintViolation();
            }
            return valid;
        }
    }
}

Answer 2

您必须更改一些内容才能使此验证生效。

控制器应该用@Validated注释，@ValuesAllowed应该在方法中注释目标参数。

import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@Validated
@RestController
@RequestMapping("/api/opportunity")
public class OpportunityController {

    @GetMapping("/vendors/list")
    public String getVendorpage(
            @RequestParam(required = false)
            @ValuesAllowed(values = {
                    "OpportunityCount",
                    "OpportunityPublishedCount",
                    "ApplicationCount",
                    "ApplicationsApprovedCount"
            }) String orderBy,
            @RequestParam(required = false) String term,
            @RequestParam(required = false) Integer page, @RequestParam(required = false) Integer size,
            @RequestParam(required = false) String sortDir) {
        return "OK";
    }
}

@ValuesAllowed 应该以 ElementType.PARAMETER 为目标，在这种情况下，您不再需要 propName 属性，因为 Spring 将验证所需的参数。

import javax.validation.Constraint;
import javax.validation.Payload;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target({ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = {ValuesAllowedValidator.class})
public @interface ValuesAllowed {

    String message() default "Field value should be from list of ";
    Class<?>[] groups() default {};
    Class<? extends Payload>[] payload() default {};

    String[] values();
}

验证器：

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
import java.util.Arrays;
import java.util.List;

public class ValuesAllowedValidator implements ConstraintValidator<ValuesAllowed, String> {

    private List<String> expectedValues;
    private String returnMessage;

    @Override
    public void initialize(ValuesAllowed requiredIfChecked) {
        expectedValues = Arrays.asList(requiredIfChecked.values());
        returnMessage = requiredIfChecked.message().concat(expectedValues.toString());
    }

    @Override
    public boolean isValid(String testValue, ConstraintValidatorContext context) {
        boolean valid = expectedValues.contains(testValue);

        if (!valid) {
            context.disableDefaultConstraintViolation();
            context.buildConstraintViolationWithTemplate(returnMessage)
                    .addConstraintViolation();
        }
        return valid;
    }
}

但上面的代码返回 HTTP 500 并使用丑陋的堆栈跟踪污染日志。为避免这种情况，您可以将这样的 @ExceptionHandler 方法放在控制器主体中（因此它的作用域仅适用于该控制器）并且您可以控制 HTTP 状态：

@ExceptionHandler(ConstraintViolationException.class)
@ResponseStatus(HttpStatus.BAD_REQUEST)
String handleConstraintViolationException(ConstraintViolationException e) {
    return "Validation error: " + e.getMessage();
}

...或者您可以将此方法放在单独的@ControllerAdvice 类中，并对该验证具有更多控制权，例如在所有控制器或仅所需的控制器上使用它。