a String to an instance of MyDate, one can write

 <pre>
 <code>
     ELProcessor elp = new ELProcessor();
     elp.getELManager().addELResolver(new TypeConverter() {
         Object convertToType(ELContext context, Object obj, Class&lt;?&gt; type) {
             if ((obj instanceof String) &amp;&amp; type == MyDate.class) {
                 context.setPropertyResolved(obj, type);
                 return (obj == null)? null: new MyDate(obj.toString());
             }
             return null;
         }
   