code: public String[] getArray(final String key, final String[] def) {
  		final String[] value = getArray(key);
  		if (value != null) {
  			return value;
  		}
  		return def;
  	}
docs: Gets the prefixed key and parse it to an String[]<br>
  Each comma-separated list can be used. If the key couldn't get found, the
  default will be used.
  
  @param key
  the key
  @param def
  default value
  
  @return String[]