************************************************************************
* How to use logging in HDFView and HDF-JAVA Library                   *
************************************************************************

HDFView 2.11 implemented logging in the java code with support for the
slf4j 1.7.5 package. HDFView by default uses the slf4j-nop-1.7.5.jar.
This suppresses any logging information. See http://www.slf4j.org/ for
more information on the slf4j package.

To enable logging in HDFView or HDFJava Library, you must include the
slf4j-simple-1.7.5 jar (or other slf4j compatible jar file) by overriding
the default jar file.

HDFView:
  To enable logging in HDFView requires that HDFView uses an alternate
  classpath. This can be accomplished by changing the command line in the
  hdfview script in the bin folder.

  Windows:
      start "HDFView" "%JAVABIN%\javaw.exe" -Xmx1024M -Djava.library.path="%INSTALLDIR%\lib;%INSTALLDIR%\lib\ext" -Dhdfview.root="%INSTALLDIR%" -jar "%INSTALLDIR%\lib\jhdfview.jar" -root "%INSTALLDIR%\share" %1
    to
      start "HDFView" "%JAVABIN%\javaw.exe" -Xmx1024M -Djava.library.path="%INSTALLDIR%\lib;%INSTALLDIR%\lib\ext" -Dorg.slf4j.simpleLogger.defaultLogLevel=debug -Dhdfview.root="%INSTALLDIR%" -cp "%INSTALLDIR%\lib\jhdfview.jar;%INSTALLDIR%\lib\ext\slf4j-simple-1.7.5.jar;%INSTALLDIR%\lib\slf4j-api-1.7.5.jar;%INSTALLDIR%\lib" hdf.view.HDFView -root "%INSTALLDIR%\share" %1

  Linux:
      $JAVABIN/java -Xmx1024M -Djava.library.path="$INSTALLDIR/lib:$INSTALLDIR/lib/ext" -Dhdfview.root="$INSTALLDIR" -jar "$INSTALLDIR/lib/jhdfview.jar" -root "$INSTALLDIR/share" $*
    to
      $JAVABIN/java -Xmx1024M -Djava.library.path="$INSTALLDIR/lib:$INSTALLDIR/lib/ext" -Dorg.slf4j.simpleLogger.defaultLogLevel=debug -Dhdfview.root="$INSTALLDIR -cp $INSTALLDIR/lib/jhdfview.jar:$INSTALLDIR/lib/ext/slf4j-simple-1.7.5.jar:$INSTALLDIR/lib/slf4j-api-1.7.5.jar:$INSTALLDIR/lib hdf.view.HDFView -root $INSTALLDIR/share $*

NOTE that the "-jar $INSTALLDIR/lib/jhdfview.jar" section is changed to
     "-cp <list of jars>" and add the -Dorg.slf4j.simpleLogger.defaultLogLevel

org.slf4j.simpleLogger.defaultLogLevel is the default log level for all instances of SimpleLogger.
It must be one of ("trace", "debug", "info", "warn", or "error"). If not specified, defaults to "info".

************************************************************************
* Example use of logging and HDF-JAVA Library                          *
************************************************************************

public class H5test {
    /**
     * Add logger for this class
     */

    private final static org.slf4j.Logger log = org.slf4j.LoggerFactory.getLogger(H5test.class);

    ...
    public int H5function (int arg)
    {
        log.info("H5function called with {}", arg);
        if (arg < 0) {
            log.warn("H5function with negative argument");
            return 0;
        }
        try {
            some_function();
        }
        catch (Exception ex) {
            log.debug("some_function failed: ", ex);
        }

        log.trace("H5function finished");

        return (arg * 3);
    }