I got ClassCastException when trying to upgrade from ColumnDecorator to DisplayTagColumnDecorator Interface. I made the proper changes in my Decorator implementations, but it just keeps throwing a ClassCastException.

Here is the code of my decorator :

import java.util.Date;

import javax.servlet.jsp.PageContext;

import org.apache.log4j.Logger;
import org.displaytag.decorator.DisplaytagColumnDecorator;
import org.displaytag.exception.DecoratorException;
import org.displaytag.properties.MediaTypeEnum;

import fr.acoss.tech.format.Utiles;

public class DateWrapper implements DisplaytagColumnDecorator {

private static final Logger LOGGER = Logger.getLogger(DateWrapper.class);

public String decorate(Object aValue, PageContext aContext, MediaTypeEnum aMediaType)
        throws DecoratorException {

    if (LOGGER.isDebugEnabled()) {
        LOGGER.debug("decorate() - [Début]");
    }

    if (aValue == null) {
        return "";
    }

    try {
        if (aValue instanceof Date) {
            return Utiles.formatDateFrancais((Date) aValue);
        } else if (aValue instanceof String) {
            return Utiles.formatDate(((String) aValue));
        } else {
            return "";
        }

    } catch (Exception e) {
        LOGGER.error(
                "decorate(Object value) - Erreur lors de la transformation dans un format date de '"

                        + aValue + "' - Exception:", e);
        return "#err";
    }
}

}

Utiles.formatDateFrancais returns a String

Here is the tag statement in the JSP :

==================================
<display:table name="RECU_CB" pagesize="10" requestURI="/servlet/cotisant" class="main" id="bean_recu" sort="list">
<display:caption>MESSAGES RE&Ccedil;US</display:caption>
<display:column class="center" property="date" title="Date" sortable="true" sortProperty="date" headerClass="sortable" decorator="fr.acoss.dcl.gui.displaytag.decorator.DateWrapper" />
<!-- ... -->
</display:table>
===============================================

Exception: [.DecoratorFactory] Unable to load fr.acoss.dcl.gui.displaytag.decorator.DateWrapper due to a java.lang.ClassCastException exception Cause: fr.acoss.dcl.gui.displaytag.decorator.DateWrapper
at org.displaytag.decorator.DecoratorFactory.loadColumnDecorator(DecoratorFactory.java:108)
at org.displaytag.tags.ColumnTag.addHeaderToTable(ColumnTag.java:621)
at org.displaytag.tags.ColumnTag.doEndTag(ColumnTag.java:547)

If I remove the decorator attribute in the displaytag, the array is well displayed