使用HibernateValidator进行跨字段验证不会显示任何错误消息 [英] Cross field validation with HibernateValidator displays no error messages

问题描述

我正在使用此答案.以下是约束描述符(验证程序接口).

I'm validating two fields, "password" and "confirmPassword" on the form for equality using HibernateValidator as specified in this answer. The following is the constraint descriptor (validator interface).

package constraintdescriptor;

import constraintvalidator.FieldMatchValidator;
import javax.validation.Constraint;
import javax.validation.Payload;
import java.lang.annotation.Documented;
import static java.lang.annotation.ElementType.ANNOTATION_TYPE;
import static java.lang.annotation.ElementType.TYPE;
import java.lang.annotation.Retention;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
import java.lang.annotation.Target;

@Target({TYPE, ANNOTATION_TYPE})
@Retention(RUNTIME)
@Constraint(validatedBy = FieldMatchValidator.class)
@Documented
public @interface FieldMatch
{
    String message() default "{constraintdescriptor.fieldmatch}";
    Class<?>[] groups() default {};
    Class<? extends Payload>[] payload() default {};

    /**
     * @return The first field
     */
    String first();

    /**
     * @return The second field
     */
    String second();

    /**
     * Defines several <code>@FieldMatch</code> annotations on the same element
     *
     * @see FieldMatch
     */
    @Target({TYPE, ANNOTATION_TYPE})
    @Retention(RUNTIME)
    @Documented
    public @interface List{
        FieldMatch[] value();
    }
}

以下是约束验证器(实现类).

package constraintvalidator;

import constraintdescriptor.FieldMatch;
import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
import org.apache.commons.beanutils.BeanUtils;

public final class FieldMatchValidator implements ConstraintValidator<FieldMatch, Object>
{
    private String firstFieldName;
    private String secondFieldName;

    public void initialize(final FieldMatch constraintAnnotation) {
        firstFieldName = constraintAnnotation.first();
        secondFieldName = constraintAnnotation.second();
        //System.out.println("firstFieldName = "+firstFieldName+"   secondFieldName = "+secondFieldName);
    }

    public boolean isValid(final Object value, final ConstraintValidatorContext cvc) {
        try {
            final Object firstObj = BeanUtils.getProperty(value, firstFieldName );
            final Object secondObj = BeanUtils.getProperty(value, secondFieldName );
            //System.out.println("firstObj = "+firstObj+"   secondObj = "+secondObj);
            return firstObj == null && secondObj == null || firstObj != null && firstObj.equals(secondObj);
        }
        catch (final Exception e) {
            System.out.println(e.toString());
        }
        return true;
    }
}

---

以下是与JSP页面映射的验证器bean(由commandName="tempBean"和<form:form></form:form>标记指定).

---

The following is the validator bean which is mapped with the JSP page (as specified commandName="tempBean" with the <form:form></form:form> tag).

package validatorbeans;

import constraintdescriptor.FieldMatch;
import javax.validation.constraints.Size;
import org.hibernate.validator.constraints.NotEmpty;

@FieldMatch.List({
    @FieldMatch(first = "password", second = "confirmPassword", message = "The password fields must match", groups={TempBean.ValidationGroup.class})
})

public final class TempBean
{        
    @NotEmpty(groups={ValidationGroup.class}, message="Might not be left blank.")
    private String password;
    @NotEmpty(groups={ValidationGroup.class}, message="Might not be left blank.")
    private String confirmPassword;

    public interface ValidationGroup {};

    //Getters and setters                
}

更新

一切正常，并按预期进行验证.剩下的一件事就是在@FieldMatch中的TempBean类上方显示指定的错误消息，即不显示，即只有一个问题: 如何在以下情况下在JSP页面上显示错误消息:验证违反发生了吗?

It's all working correctly and does the validation intended. Just one thing remains is to display the specified error message above the TempBean class within @FieldMatch is not being displayed i.e only one question : how to display error messages on the JSP page when validation violation occurs?

(TempBean类中的两个字段password和confirmPassword上的注释@NotEmpty可以正常工作，并在出现冲突时显示指定的消息，@FieldMatch则不会发生这种情况.)

(the annotation @NotEmpty on both of the fields password and confirmPassword in the TempBean class works and displays the specified messages on violation, the thing is not happening with @FieldMatch).

我根据此问题使用了验证组 ="http://digitaljoel.nerd-herders.com/2010/12/28/spring-mvc-and-jsr-303-validation-groups/" rel ="nofollow noreferrer">此博客及其效果很好，不会出现显示错误消息的中断(看起来好像是这样).

I'm using validation group based on this question as specified in this blog and it works well causing no interruption in displaying error messages (as it might seem to be).

在JSP页面上，这两个字段的指定如下.

On the JSP page these two fields are specified as follows.

<form:form id="mainForm" name="mainForm" method="post" action="Temp.htm" commandName="tempBean">

    <form:password path="password"/>
    <font style="color: red"><form:errors path="password"/></font><br/>

    <form:password path="confirmPassword"/>
    <font style="color: red"><form:errors path="confirmPassword"/></font><br/>

</form:form>

推荐答案

您可以尝试使用isValid方法来实现吗? (这肯定对我在实时项目中起作用):

Could you try your isValid method to be like this? (this is certainly working for me in live project):

 public boolean isValid(final Object value, final ConstraintValidatorContext cvc){
    boolean toReturn = false;

    try{
        final Object firstObj = BeanUtils.getProperty(value, firstFieldName );
        final Object secondObj = BeanUtils.getProperty(value, secondFieldName );

        //System.out.println("firstObj = "+firstObj+"   secondObj = "+secondObj);

        toReturn = firstObj == null && secondObj == null || firstObj != null && firstObj.equals(secondObj);
    }
    catch (final Exception e){
        System.out.println(e.toString());
    }
    //If the validation failed
    if(!toReturn) {
        cvc.disableDefaultConstraintViolation();
        //In the initialiaze method you get the errorMessage: constraintAnnotation.message();
        cvc.buildConstraintViolationWithTemplate(errorMessage).addNode(firstFieldName).addConstraintViolation();
    }
    return toReturn;
}

我还看到您实际上是使用 Object 实现ConstraintValidator接口.它应该是表单中的支持对象:

Also I see that you are implementing the ConstraintValidator interface with an Object, literally. It should be the backing object that you have from your form:

tempBean//您实际上在commandName中指定的那个.

tempBean // the one that you specify in the commandName actually.

因此您的实现应如下所示:

So you implementation should like this:

 implements ConstraintValidator<FieldMatch, TempBean>

这可能不是这里的问题，但是作为将来的参考，应该是这样.

This is probably not the issue here, but as a future reference, this is how it should be.

更新

在FieldMatch接口/注释内部，您有两种方法:第一种和第二种，例如，再添加一个称为errorMessage的方法:

Inside your FieldMatch interface/annotation you have two methods : first and second, add one more called errorMessage for example:

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

/**
 * @return The first field
 */
String first();

/**
 * @return The second field
 */
String second();

/**
  @return the Error Message
 */
String errorMessage

在Validation类中查找您的方法-您将在其中获取第一个和第二个字段名称.因此，只需添加errorMessage即可，例如:

Look inside you method from the Validation class - you are getting the first and second field names there., so just add the errorMessage, like this for example:

  private String firstFieldName;
  private String secondFieldName;
  //get the error message name
  private String errorMessagename; 
public void initialize(final FieldMatch constraintAnnotation)
{
    firstFieldName = constraintAnnotation.first();
    secondFieldName = constraintAnnotation.second();
    errorMessageNAme = constraintAnnotation.errorMessage(); 

    //System.out.println("firstFieldName = "+firstFieldName+"   secondFieldName = "+secondFieldName);
}

在isValida内部可以获取它，就像您对第一个和第二个字段名称进行操作并使用它一样.

Inside isValida get it, the same way you do for first and second field name and use it.

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