Using the

<f:convertNumber/>

together with It seems that the BigDecimal results in a java.lang.IllegalArgumentException: java.lang.ClassCastException. To get around this, either use

<f:converter converterId="javax.faces.BigDecimal"/>

or use your own converter, eg:

import java.math.BigDecimal;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.convert.NumberConverter;

public class BigDecimalConverter extends NumberConverter {

    public Object getAsObject(FacesContext context, UIComponent component, String string) {
        Object value = super.getAsObject(context, component, string); 
        if (value instanceof Long) return BigDecimal.valueOf((Long) value);
        if (value instanceof Double) return BigDecimal.valueOf((Double) value);
        return value;
    }
}

Thanks so far to jbforum (http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4079626#4079626). But I still have a problem when I want to use something like maxFractionDigits or minFractionDigits. These attributes are not supported by tag…