code: public static boolean isSimple(Object aObject)
     {
        if(aObject == null || 
           aObject.getClass() ==null || 
           aObject.getClass().getName() == null )       
           return true;
           
        return aObject instanceof Date ||                     
        aObject instanceof Number ||
        aObject instanceof String ||
        aObject instanceof Character ||
        aObject instanceof StringBuffer ||
        aObject.getClass().getName().indexOf("java.lang") > -1;
     }
docs: --------------------------------------------------------