[GIS] Geotools – Create a line layer

geotoolsjavalayersline

I am using the Geotools library to develop a Java Swing application. I am having a problem creating a layer with lines between points. Can someone help me?

Here my code:

import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.geom.GeometryFactory;
import com.vividsolutions.jts.geom.LineString;
import java.awt.Color;
import static org.geotools.coverage.processing.operation.Interpolate.TYPE;
import org.geotools.feature.DefaultFeatureCollection;
import org.geotools.feature.simple.SimpleFeatureBuilder;
import org.geotools.geometry.jts.JTSFactoryFinder;
import org.geotools.map.FeatureLayer;
import org.geotools.map.Layer;
import org.geotools.styling.SLD;
import org.geotools.styling.Style;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.feature.simple.SimpleFeatureType;

public class DrawLine {
    public Layer getLayerLineByCoord(Coordinate[] coords) {
        GeometryFactory geometryFactory = JTSFactoryFinder.getGeometryFactory();
        LineString line = geometryFactory.createLineString(coords);

        SimpleFeatureBuilder featureBuilder = new SimpleFeatureBuilder((SimpleFeatureType) TYPE);
        featureBuilder.add(line);
        SimpleFeature feature = featureBuilder.buildFeature("LineString_Sample");

        DefaultFeatureCollection lineCollection = new DefaultFeatureCollection();
        lineCollection.add(feature);

        Style style = SLD.createLineStyle(Color.BLUE, 1);
        return new FeatureLayer(lineCollection, style);
    }
}

Best Answer

Your schema is wrong 

import static org.geotools.coverage.processing.operation.Interpolate.TYPE;

should be 

import org.opengis.feature.simple.SimpleFeatureType;

Which leads to you needing a line like:

SimpleFeatureType TYPE = DataUtilities.createType("test", "line", "the_geom:LineString");

to create your FeatureType (or schema).

Then it works fine.

import com.ianturton.cookbook.utilities.GenerateRandomData;
import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.geom.GeometryFactory;
import com.vividsolutions.jts.geom.LineString;
import java.awt.Color;

import org.geotools.data.DataUtilities;
import org.geotools.feature.DefaultFeatureCollection;
import org.geotools.feature.SchemaException;
import org.geotools.feature.simple.SimpleFeatureBuilder;
import org.geotools.geometry.jts.JTSFactoryFinder;
import org.geotools.map.FeatureLayer;
import org.geotools.map.Layer;
import org.geotools.map.MapContent;
import org.geotools.styling.SLD;
import org.geotools.styling.Style;
import org.geotools.swing.JMapFrame;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.feature.simple.SimpleFeatureType;

public class DrawLine {
    public Layer getLayerLineByCoord(Coordinate[] coords) throws SchemaException {
        GeometryFactory geometryFactory = JTSFactoryFinder.getGeometryFactory();
        LineString line = geometryFactory.createLineString(coords);
        SimpleFeatureType TYPE = DataUtilities.createType("test", "line", "the_geom:LineString");
        SimpleFeatureBuilder featureBuilder = new SimpleFeatureBuilder((SimpleFeatureType) TYPE);
        featureBuilder.add(line);
        SimpleFeature feature = featureBuilder.buildFeature("LineString_Sample");

        DefaultFeatureCollection lineCollection = new DefaultFeatureCollection();
        lineCollection.add(feature);

        Style style = SLD.createLineStyle(Color.BLUE, 1);
        return new FeatureLayer(lineCollection, style);
    }

    public static void main(String[] args) throws SchemaException {
      MapContent map = new MapContent();
      map.setTitle("Quickstart");

      DrawLine line = new DrawLine();
      LineString ls = GenerateRandomData.createRandomLineString(10);
      Layer layer = line.getLayerLineByCoord(ls.getCoordinates());
      map.addLayer(layer);


      // Now display the map
      JMapFrame.showMap(map);

    }
}
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