How do i get a field value inside a custom Struts Validator, when the field's type is FormFile?

Question

I have a form field of type org.apache.struts.upload.FormFile. I would like to validate the field's size with a custom struts validator. To get the field's value, i have used for a text field the next code:

String value = ValidatorUtils.getValueAsString(bean,field.getProperty());

However, how do i get the value for a FormFile field? I would like to get the value as a FormFile object.

FormFile myFile = (FormFile) // TODO

Next i post the involved file's snippets.

struts-config.xml

<!DOCTYPE struts-config PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 1.2//EN" "http://jakarta.apache.org/struts/dtds/struts-config_1_2.dtd"&gt;
<struts-config>     
    <form-beans>
     <form-bean name="ChangePictureForm" type="struts.administration.ChangePictureForm">         
      <form-property name="id" type="java.lang.String" />
      <form-property name="file" type="org.apache.struts.upload.FormFile" />
        </form-bean>
    </form-beans>
...
..
.

validator-rules.xml

 <!-- User Custom Validation Rules -->
    <validator name="size"
         classname="struts.StrutsValidator"
         method="validateSize"
         methodParams="java.lang.Object,
         org.apache.commons.validator.Validator,
         org.apache.commons.validator.ValidatorAction,
         org.apache.commons.validator.Field,
         org.apache.struts.action.ActionMessages,
         javax.servlet.http.HttpServletRequest"
         depends=""
         msg="errors.size"/>

StrutsValidator.java

package struts;

import javax.servlet.http.HttpServletRequest;
import org.apache.commons.validator.Field;
import org.apache.commons.validator.Validator;
import org.apache.commons.validator.ValidatorAction;
import org.apache.struts.action.ActionMessages;
import org.apache.struts.upload.FormFile;
import org.apache.struts.validator.Resources;

public class StrutsValidator {
    public static boolean validateSize (
      Object bean,
      Validator validator,
      ValidatorAction validatorAction, 
      Field field,
      ActionMessages errors,
      HttpServletRequest request) {

      FormFile myFile = null; //TODO (FormFile) get it from somewhere

     String type = field.getVarValue("type");
     int size = myFile.getFileSize();

     // MySQL Storage Requirements http://dev.mysql.com/doc/refman/5.0/en/storage-requirements.html
     int allowed_size = 65538; //Blob L + 2 bytes, where L <  2 ^ 16  
     if(type.equalsIgnoreCase("tinyblob")) {
      allowed_size = 257; // L + 1 bytes, where L <  2 ^ 8
     } else if(type.equalsIgnoreCase("mediumblog")) {
      allowed_size = 16777219; // 16 Mb - L + 3 bytes, where L <  2 ^ 24
     } else if(type.equalsIgnoreCase("longblob")) {
      allowed_size = 16777219; // 4096 Mb - L + 4 bytes, where L <  2 ^ 32
     } 
     try {
      if(size>=allowed_size) {      
       errors.add(field.getKey(),Resources.getActionMessage(validator,request,validatorAction,field));
       return false;
      }
     } catch (Exception e) {
       errors.add(field.getKey(),Resources.getActionMessage(validator,request,validatorAction,field));
       return false;
     }  
     return true;
    }
}

validation.xml

<!DOCTYPE form-validation PUBLIC "-//Apache Software Foundation//DTD Commons Validator Rules Configuration 1.0//EN" "http://jakarta.apache.org/commons/dtds/validator_1_3_0.dtd"&gt;
<form-validation>
    <formset>
    <form name="ChangePictureForm">
      <field property="file" depends="required,size">   
      <arg0 key="file" />   
            <arg1 name="type" key="${var:type}" resource="false" />
            <var>
               <var-name>type</var-name>
               <var-value>blob</var-value>
            </var>
         </field>           
     </form>
    </formset>
</form-validation>