Abstract helper class for builder implementations. Includes accessors
for property values that can deal with either string values or equivalent
object types (such as string "true" or Boolean(true)).
See Also:org.jboss.mx.metadata.MetaDataBuilder author: Juha Lindfors. version: $Revision: 57200 $
Returns true for Boolean(true) and strings "true"
and "T" (case insensitive). Returns false for
Boolean(false) and strings "false" and "F".
Parameters: key - to lookup true or false throws: IllegalPropertyException - if property value is not eitherBoolean or String type or they key value isnull or a string contained an unknown value