Custom Bean Validator Not Called

[Andy Holm]

This class level bean validation call is not being called.

@Constraint(validatedBy = FieldPairRequiredValidator.class)
@Target( {ElementType.TYPE, ElementType.CONSTRUCTOR} )  
@Retention(RetentionPolicy.RUNTIME) 
@Documented
public @interface FieldPairRequired
{
	 public abstract String message() default "When one field is specified, the second must be specified as well.";    

	 public abstract Class<?>[] groups() default {}; 
	 
	 public abstract Class<? extends Payload>[] payload() default {};
	 
	 public String firstField();
	 
	 public String secondField();
}

public class FieldPairRequiredValidator implements ConstraintValidator<FieldPairRequired, Object>
{
	private String firstFieldName;
	private String secondFieldName;
	
	
	public void initialize(FieldPairRequired constraintAnnotation) 
	{
		firstFieldName = constraintAnnotation.firstField();
		secondFieldName = constraintAnnotation.secondField();
	}
	
	
	public boolean isValid(Object value, ConstraintValidatorContext context) 
	{  
		try
		{
			Object firstField = BeanUtils.getProperty(value, firstFieldName);
			Object secondField = BeanUtils.getProperty(value, secondFieldName);
			
			if((null == firstField && null != secondField) || (null == secondField && null != firstField))
			{
				return false;
			}
		}
		catch(Exception e)
		{
			System.err.println("Error: " + e);
			//ignore
		}
		
		return true;  
	}  


}

It is being called like this:

@FieldPairRequired(firstField = "id", secondField="secondId", message="Both Id and second Id must be specified when one is specified.")
@ManagedBean
@RequestScoped
public class PersonSearch

The only way I can get it to be called is when I place it on a field. Any ideas what is going on?

[Tim Holloway]

It sounds like you're attempting to attach a Validator to a container element. That doesn't work. Validators can only be applied to individual control elements.

I wrote one of these sorts of validators. It was for the traditional "enter-the-password-twice" control pair. What I had to do was attach it to one of the password controls, which then supplied its value to the validator. For the matching value in the other control, I (the validator) had to retrieve that control from the view tree, get its value, compare to the value passed in and then throw the ValidationException if they didn't match.

[Andy Holm]

What? I don't think we are on the same page, Tim.

This is a bean validation validator that uses the Hibernate bean validation annotation APIs. It has no access to the view tree (nor should it). There are examples of how this can be attached to a class so it shouldn't be a problem (http://stackoverflow.com/questions/1972933/cross-field-validation-with-hibernate-validator-jsr-303). Unfortunately, I can't get it to work anywhere other than on a field or method. It isn't called on a constructor for me either.

If it helps, I am using Apache Tomcat 6 and have downloaded hibernate-validator-4.1.0.jar to patch it to support annotations in EE 6. More information on what I did is shown here under Bean Validation (http://weblogs.java.net/blog/cayhorstmann/archive/2009/12/29/jsf-20-and-tomcat).

If this needs to be moved to a different part of the forum than the JSF section, feel free to move it.