Logging
You can configure logging by using the Java -Dlog.config=filename option. This option uses a logging configuration file that allows you to enable and disable specific logging messages. This is useful if you want to see certain types of message that are not logged by default or choose where the messages should be written. The configuration file contains details of the handler(s) used to write the messages, parameters used to format the messages and the severity of messages that should be logged at Java package or class level, plus a default value. An example file is:
# The default level FINE, WARNING, INFO, SEVERE .level=SEVERE handlers: java.util.logging.FileHandler java.util.logging.ConsoleHandler # package or class name with .level appended and then the level uk.me.parabola.imgfmt.level=INFO uk.me.parabola.mkgmap.build.level=INFO uk.me.parabola.mkgmap.main.Main.level=INFO uk.me.parabola.mkgmap.main.MapMaker.level=INFO uk.me.parabola.mkgmap.general.RoadNetwork.level=INFO uk.me.parabola.mkgmap.general.MapLine.level=INFO uk.me.parabola.mkgmap.osmstyle.level=INFO uk.me.parabola.mkgmap.reader.osm.level=INFO uk.me.parabola.mkgmap.reader.osm.xml.level=INFO uk.me.parabola.mkgmap.reader.osm.RestrictionRelation.level=FINE uk.me.parabola.mkgmap.reader.osm.Restriction.level=FINE # For ConsoleHandler java.util.logging.ConsoleHandler.level=WARNING java.util.logging.ConsoleHandler.formatter=uk.me.parabola.log.UsefulFormatter # For FileHandler java.util.logging.FileHandler.level=FINE java.util.logging.FileHandler.encoding=UTF-8 java.util.logging.FileHandler.formatter=uk.me.parabola.log.UsefulFormatter java.util.logging.FileHandler.limit=20000000 java.util.logging.FileHandler.count=4 java.util.logging.FileHandler.pattern=mkgmap.log java.util.logging.FileHandler.append=false
The above example enables certain informational messages and uses FileHandler to send them to a log file, with warning and error messages being also sent to stderr via ConsoleHandler.
Mkgmap provides UsefulFormatter to help format messages, but you can use the standard Java SimpleFormatter if you prefer.
In addition to the standard Java levels, mkgmap uses three additional levels DIAGNOSTIC (1100), ECHO (1200) and OVERRIDE (1300) for messages from its diagnostic options, echo/echotags style compiler actions and to display mkgmap startup and completion information. You can use the numeric values but not the names to specify these levels in a logging configuration file.
Further information can be found at https://docs.oracle.com/javase/8/docs/technotes/guides/logging/overview.html
If you see messages that contain non-ASCII characters which are not displaying properly in the console, you may need to use the Java -Dfile.encoding=<codepage> option and/or precede the mkgmap command line with a chcp command to make sure that the Java environment has the same code page as the shell it is being run from. This is especially likely on the Windows platform where the Java environment uses the Windows default code page, but the Windows command shell normally uses a different code page.