Assuming you have at least 2 location objects you can draw a polyline.
This method draws a semi-transparent blue line on the map given a list
of locations. This code is taken from an application currently on the
Android Play store (Simply Walking).
private void drawPrimaryLinePath( ArrayList<Location> listLocsToDraw )
{
if ( map == null )
{
return;
}
if ( listLocsToDraw.size() < 2 )
{
return;
}
PolylineOptions options = new PolylineOptions();
options.color( Color.parseColor( "#CC0000FF" ) );
options.width( 5 );
options.visible( true );
for ( Location locRecorded : listLocsToDraw )
{
options.add( new LatLng( locRecorded.getLatitude(),
locRecorded.getLongitude() ) );
}
map.addPolyline( options );
}