在Hibernate Validator 4.x中是否有跨字段验证的实现(或第三方实现)?如果不是,实现跨字段验证器的最干净的方法是什么?

例如,如何使用API来验证两个bean属性是否相等(例如验证密码字段与密码验证字段是否匹配)。

在注释中,我期望如下内容:

public class MyBean {
  @Size(min=6, max=50)
  private String pass;

  @Equals(property="pass")
  private String passVerify;
}

当前回答

我很惊讶这个没有开箱即用。不管怎样,这里有一个可能的解决方案。

我创建了一个类级验证器,而不是原始问题中描述的字段级验证器。

下面是注释代码:

package com.moa.podium.util.constraints;

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.*;

import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

import javax.validation.Constraint;
import javax.validation.Payload;

@Target({TYPE, ANNOTATION_TYPE})
@Retention(RUNTIME)
@Constraint(validatedBy = MatchesValidator.class)
@Documented
public @interface Matches {

  String message() default "{com.moa.podium.util.constraints.matches}";

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

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

  String field();

  String verifyField();
}

以及验证器本身:

package com.moa.podium.util.constraints;

import org.mvel2.MVEL;

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;

public class MatchesValidator implements ConstraintValidator<Matches, Object> {

  private String field;
  private String verifyField;


  public void initialize(Matches constraintAnnotation) {
    this.field = constraintAnnotation.field();
    this.verifyField = constraintAnnotation.verifyField();
  }

  public boolean isValid(Object value, ConstraintValidatorContext context) {
    Object fieldObj = MVEL.getProperty(field, value);
    Object verifyFieldObj = MVEL.getProperty(verifyField, value);

    boolean neitherSet = (fieldObj == null) && (verifyFieldObj == null);

    if (neitherSet) {
      return true;
    }

    boolean matches = (fieldObj != null) && fieldObj.equals(verifyFieldObj);

    if (!matches) {
      context.disableDefaultConstraintViolation();
      context.buildConstraintViolationWithTemplate("message")
          .addNode(verifyField)
          .addConstraintViolation();
    }

    return matches;
  }
}

注意,我已经使用MVEL来检查正在验证的对象的属性。这可以用标准反射api代替,或者如果它是您正在验证的特定类,则使用访问器方法本身。

@Matches注释可以像下面这样使用在bean上:

@Matches(field="pass", verifyField="passRepeat")
public class AccountCreateForm {

  @Size(min=6, max=50)
  private String pass;
  private String passRepeat;

  ...
}

作为免责声明,我在最后5分钟写了这篇文章,所以我可能还没有解决所有的错误。如果有任何错误,我将更新答案。

其他回答

非常好的解决方案,布拉德豪斯。是否有办法将@Matches注释应用到多个字段?

编辑: 下面是我想出的解决方案来回答这个问题,我修改了约束以接受数组而不是单个值:

@Matches(fields={"password", "email"}, verifyFields={"confirmPassword", "confirmEmail"})
public class UserRegistrationForm  {

    @NotNull
    @Size(min=8, max=25)
    private String password;

    @NotNull
    @Size(min=8, max=25)
    private String confirmPassword;


    @NotNull
    @Email
    private String email;

    @NotNull
    @Email
    private String confirmEmail;
}

注释的代码:

package springapp.util.constraints;

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.*;

import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

import javax.validation.Constraint;
import javax.validation.Payload;

@Target({TYPE, ANNOTATION_TYPE})
@Retention(RUNTIME)
@Constraint(validatedBy = MatchesValidator.class)
@Documented
public @interface Matches {

  String message() default "{springapp.util.constraints.matches}";

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

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

  String[] fields();

  String[] verifyFields();
}

以及实现:

package springapp.util.constraints;

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;

import org.apache.commons.beanutils.BeanUtils;

public class MatchesValidator implements ConstraintValidator<Matches, Object> {

    private String[] fields;
    private String[] verifyFields;

    public void initialize(Matches constraintAnnotation) {
        fields = constraintAnnotation.fields();
        verifyFields = constraintAnnotation.verifyFields();
    }

    public boolean isValid(Object value, ConstraintValidatorContext context) {

        boolean matches = true;

        for (int i=0; i<fields.length; i++) {
            Object fieldObj, verifyFieldObj;
            try {
                fieldObj = BeanUtils.getProperty(value, fields[i]);
                verifyFieldObj = BeanUtils.getProperty(value, verifyFields[i]);
            } catch (Exception e) {
                //ignore
                continue;
            }
            boolean neitherSet = (fieldObj == null) && (verifyFieldObj == null);
            if (neitherSet) {
                continue;
            }

            boolean tempMatches = (fieldObj != null) && fieldObj.equals(verifyFieldObj);

            if (!tempMatches) {
                addConstraintViolation(context, fields[i]+ " fields do not match", verifyFields[i]);
            }

            matches = matches?tempMatches:matches;
        }
        return matches;
    }

    private void addConstraintViolation(ConstraintValidatorContext context, String message, String field) {
        context.disableDefaultConstraintViolation();
        context.buildConstraintViolationWithTemplate(message).addNode(field).addConstraintViolation();
    }
}

如果您正在使用Spring框架,那么您可以使用Spring表达式语言(SpEL)。我写了一个小库,提供了基于SpEL的JSR-303验证器——它使得跨领域验证变得轻而易举!看看https://github.com/jirutka/validator-spring。

这将验证密码字段的长度和相等性。

@SpELAssert(value = "pass.equals(passVerify)",
            message = "{validator.passwords_not_same}")
public class MyBean {

    @Size(min = 6, max = 50)
    private String pass;

    private String passVerify;
}

您还可以轻松地进行修改,仅当密码字段不为空时才验证密码字段。

@SpELAssert(value = "pass.equals(passVerify)",
            applyIf = "pass || passVerify",
            message = "{validator.passwords_not_same}")
public class MyBean {

    @Size(min = 6, max = 50)
    private String pass;

    private String passVerify;
}

你们太棒了。真是惊人的想法。我最喜欢阿尔伯托芬和麦金的,所以我决定把他们的想法结合起来。并开发一些通用的解决方案,以满足所有情况。以下是我提出的解决方案。

@Documented
@Constraint(validatedBy = NotFalseValidator.class)
@Target({ElementType.METHOD, ElementType.FIELD,ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
public @interface NotFalse {


    String message() default "NotFalse";
    String[] messages();
    String[] properties();
    String[] verifiers();

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

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

}

public class NotFalseValidator implements ConstraintValidator<NotFalse, Object> {
    private String[] properties;
    private String[] messages;
    private String[] verifiers;
    @Override
    public void initialize(NotFalse flag) {
        properties = flag.properties();
        messages = flag.messages();
        verifiers = flag.verifiers();
    }

    @Override
    public boolean isValid(Object bean, ConstraintValidatorContext cxt) {
        if(bean == null) {
            return true;
        }

        boolean valid = true;
        BeanWrapper beanWrapper = PropertyAccessorFactory.forBeanPropertyAccess(bean);

        for(int i = 0; i< properties.length; i++) {
           Boolean verified = (Boolean) beanWrapper.getPropertyValue(verifiers[i]);
           valid &= isValidProperty(verified,messages[i],properties[i],cxt);
        }

        return valid;
    }

    boolean isValidProperty(Boolean flag,String message, String property, ConstraintValidatorContext cxt) {
        if(flag == null || flag) {
            return true;
        } else {
            cxt.disableDefaultConstraintViolation();
            cxt.buildConstraintViolationWithTemplate(message)
                    .addPropertyNode(property)
                    .addConstraintViolation();
            return false;
        }

    }



}

@NotFalse(
        messages = {"End Date Before Start Date" , "Start Date Before End Date" } ,
        properties={"endDateTime" , "startDateTime"},
        verifiers = {"validDateRange" , "validDateRange"})
public class SyncSessionDTO implements ControllableNode {
    @NotEmpty @NotPastDate
    private Date startDateTime;

    @NotEmpty
    private Date endDateTime;



    public Date getStartDateTime() {
        return startDateTime;
    }

    public void setStartDateTime(Date startDateTime) {
        this.startDateTime = startDateTime;
    }

    public Date getEndDateTime() {
        return endDateTime;
    }

    public void setEndDateTime(Date endDateTime) {
        this.endDateTime = endDateTime;
    }


    public Boolean getValidDateRange(){
        if(startDateTime != null && endDateTime != null) {
            return startDateTime.getTime() <= endDateTime.getTime();
        }

        return null;
    }

}

我没有评论第一个答案的名声,但我想补充的是,我已经为获胜的答案添加了单元测试,并有以下观察:

如果第一个或字段名出错,就会出现验证错误,就好像值不匹配一样。不要被拼写错误绊倒。

@FieldMatch(first=“invalidFieldName1”, second=“validFieldName2”)

验证器将接受等效的数据类型,即这些都将通过FieldMatch:

private String stringField = "1"; private Integer integerField = new Integer(1) private int intField = 1;

如果字段的对象类型没有实现equals,则验证将失败。

我很惊讶这个没有开箱即用。不管怎样,这里有一个可能的解决方案。

我创建了一个类级验证器,而不是原始问题中描述的字段级验证器。

下面是注释代码:

package com.moa.podium.util.constraints;

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.*;

import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

import javax.validation.Constraint;
import javax.validation.Payload;

@Target({TYPE, ANNOTATION_TYPE})
@Retention(RUNTIME)
@Constraint(validatedBy = MatchesValidator.class)
@Documented
public @interface Matches {

  String message() default "{com.moa.podium.util.constraints.matches}";

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

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

  String field();

  String verifyField();
}

以及验证器本身:

package com.moa.podium.util.constraints;

import org.mvel2.MVEL;

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;

public class MatchesValidator implements ConstraintValidator<Matches, Object> {

  private String field;
  private String verifyField;


  public void initialize(Matches constraintAnnotation) {
    this.field = constraintAnnotation.field();
    this.verifyField = constraintAnnotation.verifyField();
  }

  public boolean isValid(Object value, ConstraintValidatorContext context) {
    Object fieldObj = MVEL.getProperty(field, value);
    Object verifyFieldObj = MVEL.getProperty(verifyField, value);

    boolean neitherSet = (fieldObj == null) && (verifyFieldObj == null);

    if (neitherSet) {
      return true;
    }

    boolean matches = (fieldObj != null) && fieldObj.equals(verifyFieldObj);

    if (!matches) {
      context.disableDefaultConstraintViolation();
      context.buildConstraintViolationWithTemplate("message")
          .addNode(verifyField)
          .addConstraintViolation();
    }

    return matches;
  }
}

注意,我已经使用MVEL来检查正在验证的对象的属性。这可以用标准反射api代替,或者如果它是您正在验证的特定类,则使用访问器方法本身。

@Matches注释可以像下面这样使用在bean上:

@Matches(field="pass", verifyField="passRepeat")
public class AccountCreateForm {

  @Size(min=6, max=50)
  private String pass;
  private String passRepeat;

  ...
}

作为免责声明,我在最后5分钟写了这篇文章,所以我可能还没有解决所有的错误。如果有任何错误,我将更新答案。