public Enumeration keys() throws MqttPersistenceException {
  checkIsOpen();
  Enumeration files=getFiles();
  Vector result=new Vector();
  while (files.hasMoreElements()) {
    String filename=(String)files.nextElement();
    String key=filename.substring(0,filename.length() - MESSAGE_FILE_EXTENSION.length());
    result.addElement(key);
  }
  return result.elements();
}

public Enumeration keys ( ) throws MqttPersistenceException { checkIsOpen ( ) ; Enumeration files = getFiles ( ) ; Vector result = new Vector ( ) ; while ( files . hasMoreElements ( ) ) { String filename = ( String ) files . nextElement ( ) ; String key = filename . substring ( 0 , filename . length ( ) - MESSAGE_FILE_EXTENSION . length ( ) ) ; result . addElement ( key ) ; } return result . elements ( ) ; }
returns all of the persistent data from the previously specified persistence directory .
