PortalLogFormatter conforms to the logging format defined by the
Log Working Group in Java Webservices Org.
The specified format is
"[#|DATETIME|LOG_LEVEL|PRODUCT_ID|LOGGER NAME|OPTIONAL KEY VALUE PAIRS|MESSAGE|#]\n"
Message also includes the stacktrace only if it is set on the PortalLogFormatter.
By default it is not displayed. For any other formatter this feature is not available.
It needs to be handled by the formatter itself.