How I can get all the points of a polygon in a shapeFile .shp using GeoTools?

Question

This is my first question in stackoverflow so I hope that I am doing it in the right way.

I am using geotools to read a shapeFile (.shp) and I cannot find the function to get all the points of the polygon. By now I have the following code:

public class ImportShapeFileService implements ImportShapeFileServiceInterface {

    @Override
    public void loadShapeFile(File shapeFile) throws MdfException {

        FileDataStore store;
        try {
            store = FileDataStoreFinder.getDataStore(shapeFile);
            SimpleFeatureSource featureSource = store.getFeatureSource();
            SimpleFeatureCollection collection = featureSource.getFeatures();

            ReferencedEnvelope env = collection.getBounds();
            double left = env.getMinX();
            double right = env.getMaxX();
            double top = env.getMaxY();
            double bottom = env.getMinY();

        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

I am getting the four bounds of the shapFile, but not the points of the polygon that contains, is it possible to do that?

Thank you.

When I said the points I meant the latitude and longitude of each point of the figure. — Alex Blasco, Oct 06 '17 at 15:28
`SimpleFeatureIterator` and examine the geometry, for [example](http://docs.geotools.org/stable/userguide/tutorial/geometry/geometrycrs.html)? — trashgod, Oct 06 '17 at 17:59

score 2 · Accepted Answer · answered Oct 07 '17 at 10:54

2

Depending on what you want to do with the points, I'd do something like:

try(SimpleFeatureIterator itr1 = features.features()){
  while(itr1.hasNext()){
     SimpleFeature f = itr1.next();
     Geometry g = (Geometry)f.getDefaultGeometry();
     Coordinate[] coords = g.getCoordinates();
     // do something with the coordinates
   }
}

If you must have Point rather than just the coordinates (and you are sure you have polygons then you could use:

  Geometry g = (Geometry)f.getDefaultGeometry();
  for(int i=0;i<g.getNumPoints();i++) {
    Point p=((Polygon)g).getExteriorRing().getPointN(i);
  }

answered Oct 07 '17 at 10:54

Ian Turton

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`g.getCoordinates()` doesn't exist anymore in version "23-SNAPSHOT". :/ – Neph Sep 05 '19 at 08:22
1

It seems to see https://locationtech.github.io/jts/javadoc/org/locationtech/jts/geom/Geometry.html#getCoordinates-- Geometry is a JTS object not a GeoTools one. – Ian Turton Sep 05 '19 at 08:31
I see, thanks! Do you happen to know how to get a `CoordinateXYMZ` object from it? `g.getCoordinate()` returns a normal `Coordinate` one that has an `M` value but it's `NaN`, even though the shapefile has properly set `M` values. – Neph Sep 05 '19 at 09:27
you need to ask a new question – Ian Turton Sep 05 '19 at 09:36
Yes, I planning on doing that if you didn't know the answer. – Neph Sep 05 '19 at 09:45

How I can get all the points of a polygon in a shapeFile .shp using GeoTools?

1 Answers1