First, you can directly give a xml file to open it directly on ganttproject.
Ex : java -jar ganttproject.jar myproject.xml
The second possiblity is to export the project as HTML pages or a PNG image.
Ex : java -jar ganttproject.jar -html myproject.xml directory to export the project as a web page in the specified directory.
Ex : java -jar ganttproject.jar -png myproject.xml myproject.png to export the project chart as myproject.png.
In all these cases the project file name can either be a file on local disk or an URL. If the URL is password-protected, you can give
credentials this way:
Ex : java -jar ganttproject.jar http://username:password@example.com/filename