Java tutorial
/* * Licensed to Prodevelop SL under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The Prodevelop SL licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. * * For more information, contact: * * Prodevelop, S.L. * Pza. Don Juan de Villarrasa, 14 - 5 * 46001 Valencia * Spain * * +34 963 510 612 * +34 963 510 968 * prode@prodevelop.es * http://www.prodevelop.es * * @author Alberto Romeu Carrasco http://www.albertoromeu.com */ package es.alrocar.jpe.parser; import java.util.ArrayList; import java.util.Iterator; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import com.vividsolutions.jts.geom.Coordinate; import com.vividsolutions.jts.geom.GeometryFactory; import com.vividsolutions.jts.geom.Point; import es.prodevelop.gvsig.mini.geom.impl.jts.JTSFeature; import es.prodevelop.gvsig.mini.geom.impl.jts.JTSGeometry; /** * Utility class to parse a GeoJSON Document of Points into an array of * {@link JTSFeature} * * @author albertoromeu * */ public class GeoJSONParser { /** * Parses a GeoJSON document into an array of {@link JTSFeature} * * @param geoJSON * The GeoJSON content * @return An array of {@link JTSFeature} * @throws JSONException */ public ArrayList<JTSFeature> parse(String geoJSON) throws JSONException { ArrayList<JTSFeature> features = new ArrayList<JTSFeature>(); JSONObject json = new JSONObject(geoJSON); JSONArray feats = json.getJSONArray("features"); JSONObject feature; JTSFeature feat; final int size = feats.length(); for (int i = 0; i < size; i++) { feature = feats.getJSONObject(i); feat = parseFeature(feature); features.add(feat); } return features; } /** * Parses a single feature with a Point * * @param feature * The feature {@link JSONObject} * @return A {@link JTSFeature} * @throws JSONException */ public JTSFeature parseFeature(JSONObject feature) throws JSONException { JTSFeature feat = new JTSFeature(null); JSONObject geometry = (JSONObject) feature.get("geometry"); String geomType = geometry.get("type").toString(); if (geomType.compareTo("Point") == 0) { JSONArray coords = geometry.getJSONArray("coordinates"); double x = coords.getDouble(0); double y = coords.getDouble(1); GeometryFactory factory = new GeometryFactory(); Coordinate c = new Coordinate(); c.x = x; c.y = y; Point p = factory.createPoint(c); feat.setGeometry(new JTSGeometry(p)); } // TODO process other geometry types JSONObject props = feature.getJSONObject("properties"); Iterator it = props.keys(); String key; while (it.hasNext()) { key = it.next().toString(); feat.addField(key, props.getString(key), 0); } return feat; } }