// Get the point collection for a line feature
public static PointCollection getPointsFromLineFeature(Feature feature)
{
    // Check if the feature is a line feature
    if (feature.getGeometryType() == GeometryType.LINE)   
    {
        // Get the LineGeometry form the feature and return the points from it
        return feature.getGeometryAsLine().getPoints();
    }

    // The Feature is not a Line, so return nothing
    return null;
}