The main component is the NetMapConnector, which manages the connection to the NetMapServer. It uses the NetMapReader to parse the NetMap server stream, creating NetMapEvents for each line of output. These NetMapEvents are distributed to NetMapListeners that have registered themselves with the NetMapConnector.
The NetMapGraphicLoader is a NetMapListener that uses the NetMapEvents to create an OMGraphicList that dipicts the network topology. The NetMapConnectionHandler is an extension of the GraphicLoaderConnector, and is a component that looks in the MapHandler for NetMapConnectors. If a NetMapConnector is found, the NetMapConnectionHandler creates a NetMapGraphicLoader, GraphicLoaderPlugIn, and eventually a PlugInLayer to use to display the network on the map.
For general OpenMap use, the NetMapConnectionHandler and NetMapConnector are the only two objects that need to be created and added to the openmap.properties file in the openmap.components property. The other components will be automatically created as needed.