custom validator error path problem

dorigo.and · **Joined:** Sun Sep 22, 2013 5:54 am **Posts:** 1

Hi all,
I'm trying to develop a custom constraint for field matching (as "retype password" for example);
Everything is ok except when I try to add the error to the jsp error field like this:

Code:

context.disableDefaultConstraintViolation();
context.buildConstraintViolationWithTemplate("test").addNode(secondFieldName).addConstraintViolation();

it returns me this error:

HTTP Status 500 - java.lang.IllegalArgumentException: The source to convert from must be an instance of @javax.persistence.Transient java.lang.String; instead it was a org.andreadorigo.webapp.entities.User

These are my classes:
Person.java

Code:

@MappedSuperclass
@FieldMatch.List({
    @FieldMatch(first = "password", second = "retypePassword"),
    @FieldMatch(first = "email", second = "confirmEmail")
})
public abstract class Person {
.
.
.
}

FieldMatch.java

Code:

package org.andreadorigo.webapp.validators.costraints;

import static java.lang.annotation.ElementType.ANNOTATION_TYPE;
import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

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

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

import org.andreadorigo.webapp.validators.FieldMatchValidator;

@Target({TYPE, ANNOTATION_TYPE})
@Retention(RUNTIME)
@Constraint(validatedBy = FieldMatchValidator.class)
@Documented
public @interface FieldMatch {
    String message() default "{constraints.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
            @interface List
    {
        FieldMatch[] value();
    }
}

FieldMatchValidator.java

Code:

package org.andreadorigo.webapp.validators;

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

import org.andreadorigo.webapp.validators.costraints.FieldMatch;
import org.apache.commons.beanutils.PropertyUtils;

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

    @Override
    public void initialize(final FieldMatch constraintAnnotation)
    {
        firstFieldName = constraintAnnotation.first();
        secondFieldName = constraintAnnotation.second();
    }

    @Override
    public boolean isValid(final Object value, final ConstraintValidatorContext context)
    {
        try
        {
            final Object firstObj = PropertyUtils.getProperty(value, firstFieldName);
            final Object secondObj = PropertyUtils.getProperty(value, secondFieldName);

            
            boolean test = firstObj == null && secondObj == null || firstObj != null && firstObj.equals(secondObj); 
            
            if(!test) {
               context.disableDefaultConstraintViolation();
                context.buildConstraintViolationWithTemplate("test").addNode(secondFieldName).addConstraintViolation();
            }
            
            return test;
        }
        catch (final Exception ignore)
        {
            // ignore
        }
        return true;
    }
}

userForm.jsp

Code:

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
    
<%@taglib uri="http://www.springframework.org/tags" prefix="spring"%>
<%@taglib uri="http://www.springframework.org/tags/form" prefix="form"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>



<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
 
 
<link rel="stylesheet" type="text/css" href="<c:url value='/resources/css/test.css' />" />
<script type="text/javascript" src="<c:url value='/resources/js/jQuery.js' />"></script>

</head>
<body>
<spring:message code="label.test"/>

<form:form method="post" action="/user/add/" commandName="user" >  
   <table>
       <tr>
           <td>Email</td>
           <td><form:input path="email" /></td>
           <td><form:errors path="email"></form:errors></td>
       </tr>
       <tr>
           <td>Confirm Email</td>
           <td><form:input path="confirmEmail" /></td>
           <td><form:errors path="confirmEmail"></form:errors></td>
       </tr>
       <tr>
           <td>Password</td>
           <td><form:input path="password" /></td>
           <td><form:errors path="password"></form:errors></td>
       </tr>
       <tr>
           <td>Retype Password</td>
           <td><form:input path="retypePassword" /></td>
           <td><form:errors path="retypePassword"></form:errors></td>
       </tr>
       <tr>
           <td colspan="2">
               <input type="submit" value="Add"/>
           </td>
       </tr>
   </table>
</form:form>
<script>

</script>
</body>
</html>

Gunnar · **Joined:** Sat Jan 24, 2009 12:46 pm **Posts:** 388

Hi,

Do you have a complete stack trace for the error which have could post? Just telling from the exception message it seems to be raised by Spring's GenericConversionService class during form binding.

Quote:

Everything is ok except when I try to add the error to the jsp error field like this

Is this to say that it works with built-in constraints such as @Min, @Size etc. (i.e. these constraints are applied and if violated, an error message shows up)? If so, one possible reason may be that you're using a class-level constraint (@FieldMatch) here and Spring tries to bind the invalid value (the entire User/Person bean in this case) to some form field.

--Gunnar