Convert from ODK geoshape to GPX

diff --git a/org.argeo.app.core/src/org/argeo/app/geo/GpxUtils.java b/org.argeo.app.core/src/org/argeo/app/geo/GpxUtils.java
index 5bb7d5c6b9f1bcc682bb7e23377645d9782b70df..645b08bda8d9ed13b05c4488e1c3ad326e3f660f 100644 (file)
--- a/org.argeo.app.core/src/org/argeo/app/geo/GpxUtils.java
+++ b/org.argeo.app.core/src/org/argeo/app/geo/GpxUtils.java
@@ -2,8 +2,14 @@ package org.argeo.app.geo;
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import java.io.Writer;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Objects;
+import java.util.StringTokenizer;
 
 import javax.xml.parsers.ParserConfigurationException;
 import javax.xml.parsers.SAXParser;
@@ -25,7 +31,7 @@ import org.xml.sax.helpers.DefaultHandler;
 /** Utilities around the GPX format. */
 public class GpxUtils {
 
-       public static SimpleFeature parseGpxToPolygon(InputStream in) {
+       public static SimpleFeature parseGpxToPolygon(InputStream in) throws IOException {
                try {
                        final SimpleFeatureType TYPE = DataUtilities.createType("Area", "the_geom:Polygon:srid=4326");
                        SimpleFeatureBuilder featureBuilder = new SimpleFeatureBuilder(TYPE);
@@ -56,11 +62,37 @@ public class GpxUtils {
                        featureBuilder.add(polygon);
                        SimpleFeature area = featureBuilder.buildFeature(null);
                        return area;
-               } catch (ParserConfigurationException | SAXException | IOException | SchemaException e) {
+               } catch (ParserConfigurationException | SAXException | SchemaException e) {
                        throw new RuntimeException("Cannot convert GPX", e);
                }
        }
 
+       public static void writeGeoShapeAsGpx(String geoShape, OutputStream out) throws IOException {
+               Objects.requireNonNull(geoShape);
+               Writer writer = new OutputStreamWriter(out, StandardCharsets.UTF_8);
+               writer.append("<gpx><trk><trkseg>");
+               StringTokenizer stSeg = new StringTokenizer(geoShape.trim(), ";");
+               while (stSeg.hasMoreTokens()) {
+                       StringTokenizer stPt = new StringTokenizer(stSeg.nextToken().trim(), " ");
+                       String lat = stPt.nextToken();
+                       String lng = stPt.nextToken();
+                       String alt = stPt.nextToken();
+                       // String precision = stPt.nextToken();
+                       writer.append("<trkpt");
+                       writer.append(" lat=\"").append(lat).append('\"');
+                       writer.append(" lon=\"").append(lng).append('\"');
+                       if (!alt.equals("0.0")) {
+                               writer.append('>');
+                               writer.append("<ele>").append(alt).append("</ele>");
+                               writer.append("</trkpt>");
+                       } else {
+                               writer.append("/>");
+                       }
+               }
+               writer.append("</trkseg></trk></gpx>");
+               writer.flush();
+       }
+
        /** Singleton. */
        private GpxUtils() {
        }