1. The starting point (e.g., main) of the IDV is an application specific class derived from ucar.unidata.idv.IntegratedDataViewer, e.g., ucar.unidata.apps.example.ExampleIdv.
2. When the IDV starts up a singleton instance of this main class is created and the IntegratedDataViewer.init method is called.

       public static void main(String[] args) throws Exception {
           LogUtil.configure();
           ExampleIdv idv = new ExampleIdv(args);
       }
   

3. The application is configured by first defining an initial set of property files in the code.

           //Put the default property file in the list before we parse args 
           getArgsManager().propertyFiles.add(
               "/ucar/unidata/idv/resources/idv.properties");
           initPropertyFiles(getArgsManager().propertyFiles);
   

   The initPropertyFiles method is called to allow subclasses to modify the list. e.g., from ExampleIdv:

       public void initPropertyFiles(List files) {
           /*
             files.clear();
             files.add("/ucar/unidata/apps/example/example.properties");
           */
       }
   

4. The command line arguments are parsed by the ArgsManager.
5. The class, StateManager, is used to initialize the state.
   • Any property files on the command line are added to the list.
   • All of the properties are merged together.
   • A second pass is done loading any any property files that were defined by the idv.properties property.
   • Then any -Dname=value command line arguments are added to the properties.
6. Default system properties file.
   • Let's look at the default system properties file: idv.properties.
   • Note: the ".proplabel", ".propdesc", etc., are used in the Plugin Creator.
   • The idv.properties property defines the other properties files to use:

     idv.properties = %APPPATH%/idv.properties;%SITEPATH%/idv.properties;%USERPATH%/idv.properties;
     

   • The macros %APPPATH%, %SITEPATH%, %USERPATH% and %IDVPATH% are defined as:

     ##  %USERPATH%   The file system path of the user's .unidata/idv/application directory
     ##  %SITEPATH%   If defined (usually by the -sitepath argument) the directory path 
     ##               or url of where to find site resources
     ##  %IDVPATH%    The internal (to the jars) /ucar/unidata/idv/resources  path
     ##  %APPPATH%    The value of the idv.resourcepath property or the package of the IDV class
     

7. Let's go change the example idv.properties file.
   1. cd to /home/idv/idv/ucar/unidata/apps/example/resources
   2. Copy the file: idv.properties up one level to ucar/unidata/apps/example. This is the APPPATH.
   3. Run the Example Idv (runExample.sh)

Unidata IDV Workshop for version 6.2u2 > Java Developer Topics > IDV Startup