Reading USGS Digital Elevation (DEM) data in ArcGrid, GridFloat, and IMG formats

Question

The three formats supported by USGS for height data are the ArcGrid, GridFloat, and IMG formats. Does GeoTools read all and / or all of these formats?

So, what is an example code snippet that shows how?

If not, is there something that describes the procedure for creating my own? For example, which interfaces do I need to implement? I think I need to eventually create an instance of GridCoverage ... but I'm new to GeoTools, so this may not be true.

thank