前文中，提到了等值面的生成,后面有人经常会问等值线的生成，本文在前文的基础上做了一点修改，完成了等值线的geotools生成。
package com.lzugis.geotools; import com.amazonaws.util.json.JSONObject; import com.lzugis.CommonMethod; import com.lzugis.geotools.utils.FeaureUtil; import com.lzugis.geotools.utils.GeoJSONUtil; import com.vividsolutions.jts.geom.Geometry; import org.geotools.data.FeatureSource; import org.geotools.data.shapefile.ShapefileDataStore; import org.geotools.data.simple.SimpleFeatureCollection; import org.geotools.data.simple.SimpleFeatureSource; import org.geotools.feature.FeatureCollection; import org.geotools.feature.FeatureIterator; import org.geotools.geojson.feature.FeatureJSON; import org.opengis.feature.Feature; import org.opengis.feature.simple.SimpleFeature; import wContour.Contour; import wContour.Global.Border; import wContour.Global.PointD; import wContour.Global.PolyLine; import wContour.Global.Polygon; import wContour.Interpolate; import java.io.File; import java.io.StringWriter; import java.nio.charset.Charset; import java.util.*; /** * Created by admin on 2017/8/29. */ public class EquiSurfaceLine { private static String rootPath = System.getProperty("user.dir"); /** * 生成等值面 * * @param trainData 训练数据 * @param dataInterval 数据间隔 * @param size 大小，宽，高 * @param boundryFile 四至 * @param isclip 是否裁剪 * @return */ public String calEquiSurface(double[][] trainData, double[] dataInterval, int[] size, String boundryFile, boolean isclip) { String geojsonline = ""; try { double _undefData = -9999.0; SimpleFeatureCollection polylineCollection = null; List<PolyLine> cPolylineList = new ArrayList<PolyLine>(); List<Polygon> cPolygonList = new ArrayList<Polygon>(); int width = size[0], height = size[1]; double[] _X = new double[width]; double[] _Y = new double[height]; File file = new File(boundryFile); ShapefileDataStore shpDataStore = null; shpDataStore = new ShapefileDataStore(file.toURL()); //设置编码 Charset charset = Charset.forName("GBK"); shpDataStore.setCharset(charset); String typeName = shpDataStore.getTypeNames()[0]; SimpleFeatureSource featureSource = null; featureSource = shpDataStore.getFeatureSource(typeName); SimpleFeatureCollection fc = featureSource.getFeatures(); double minX = fc.getBounds().getMinX(); double minY = fc.getBounds().getMinY(); double maxX = fc.getBounds().getMaxX(); double maxY = fc.getBounds().getMaxY(); Interpolate.CreateGridXY_Num(minX, minY, maxX, maxY, _X, _Y); double[][] _gridData = new double[width][height]; int nc = dataInterval.length; _gridData = Interpolate.Interpolation_IDW_Neighbor(trainData, _X, _Y, 12, _undefData);// IDW插值 int[][] S1 = new int[_gridData.length][_gridData[0].length]; /** * double[][] S0, * double[] X, * double[] Y, * int[][] S1, * double undefData */ List<Border> _borders = Contour.tracingBorders(_gridData, _X, _Y, S1, _undefData); /** * double[][] S0, * double[] X, * double[] Y, * int nc, * double[] contour, * double undefData, * List<Border> borders, * int[][] S1 */ cPolylineList = Contour.tracingContourLines(_gridData, _X, _Y, nc, dataInterval, _undefData, _borders, S1);// 生成等值线 cPolylineList = Contour.smoothLines(cPolylineList);// 平滑 geojsonline = getPolylineGeoJson(cPolylineList); if (isclip) { polylineCollection = GeoJSONUtil.readGeoJsonByString(geojsonline); FeatureSource dc = clipFeatureCollection(fc, polylineCollection); geojsonline = getPolylineGeoJson(dc.getFeatures()); } } catch (Exception e) { e.printStackTrace(); } return geojsonline; } public String getPolylineGeoJson(FeatureCollection fc) { FeatureJSON fjson = new FeatureJSON(); StringBuffer sb = new StringBuffer(); try { sb.append("{\"type\": \"FeatureCollection\",\"features\": "); FeatureIterator itertor = fc.features(); List<String> list = new ArrayList<String>(); while (itertor.hasNext()) { SimpleFeature feature = (SimpleFeature) itertor.next(); StringWriter writer = new StringWriter(); fjson.writeFeature(feature, writer); list.add(writer.toString()); } itertor.close(); sb.append(list.toString()); sb.append("}"); } catch (Exception e) { e.printStackTrace(); } return sb.toString(); } public FeatureSource clipFeatureCollection(FeatureCollection fc, SimpleFeatureCollection gs) { FeatureSource cs = null; try { List<Map<String, Object>> values = new ArrayList<Map<String, Object>>(); FeatureIterator contourFeatureIterator = gs.features(); FeatureIterator dataFeatureIterator = fc.features(); while (dataFeatureIterator.hasNext()) { Feature dataFeature = dataFeatureIterator.next(); Geometry dataGeometry = (Geometry) dataFeature.getProperty( "the_geom").getValue(); while (contourFeatureIterator.hasNext()) { Feature contourFeature = contourFeatureIterator.next(); Geometry contourGeometry = (Geometry) contourFeature .getProperty("geometry").getValue(); double v = (Double) contourFeature.getProperty("value") .getValue(); if (dataGeometry.intersects(contourGeometry)) { Geometry geo = dataGeometry .intersection(contourGeometry); Map<String, Object> map = new HashMap<String, Object>(); map.put("the_geom", geo); map.put("value", v); values.add(map); } } } contourFeatureIterator.close(); dataFeatureIterator.close(); SimpleFeatureCollection sc = FeaureUtil .creatSimpleFeatureByFeilds( "polygons", "crs:4326,the_geom:LineString,value:double", values); cs = FeaureUtil.creatFeatureSourceByCollection(sc); } catch (Exception e) { e.printStackTrace(); return cs; } return cs; } public String getPolylineGeoJson(List<PolyLine> cPolylineList) { String geo = null; String geometry = " { \"type\":\"Feature\",\"geometry\":"; String properties = ",\"properties\":{ \"value\":"; String head = "{\"type\": \"FeatureCollection\"," + "\"features\": ["; String end = " ] }"; if (cPolylineList == null || cPolylineList.size() == 0) { return null; } try { for (PolyLine pPolyline : cPolylineList) { List<Object> ptsTotal = new ArrayList<Object>(); for (PointD ptD : pPolyline.PointList) { List<Double> pt = new ArrayList<Double>(); pt.add(ptD.X); pt.add(ptD.Y); ptsTotal.add(pt); } JSONObject js = new JSONObject(); js.put("type", "LineString"); js.put("coordinates", ptsTotal); geo = geometry + js.toString() + properties + pPolyline.Value + "} }" + "," + geo; } if (geo.contains(",")) { geo = geo.substring(0, geo.lastIndexOf(",")); } geo = head + geo + end; } catch (Exception e) { e.printStackTrace(); return geo; } return geo; } public static void main(String[] args) { long start = System.currentTimeMillis(); EquiSurfaceLine equiSurface = new EquiSurfaceLine(); CommonMethod cm = new CommonMethod(); double[] bounds = {110.759, 31.23, 113.112, 32.6299}; double[][] trainData = new double[3][100]; for (int i = 0; i < 100; i++) { double x = bounds[0] + new Random().nextDouble() * (bounds[2] - bounds[0]), y = bounds[1] + new Random().nextDouble() * (bounds[3] - bounds[1]), v = 0 + new Random().nextDouble() * (45 - 0); trainData[0][i] = x; trainData[1][i] = y; trainData[2][i] = v; } double[] dataInterval = new double[]{20, 25, 30, 35, 40, 45}; String boundryFile = rootPath + "/data/shp/XY_01_XZQH_PY.shp"; int[] size = new int[]{100, 100}; boolean isclip = true; try { String strJson = equiSurface.calEquiSurface(trainData, dataInterval, size, boundryFile, isclip); String strFile = rootPath + "/out/XY_01_XZQH_PY_line1.geojson"; cm.append2File(strFile, strJson); System.out.println(strFile + "差值成功, 共耗时" + (System.currentTimeMillis() - start) + "ms"); } catch (Exception e) { e.printStackTrace(); } } }技术博客
CSDN：http://blog.csdn.NET/gisshixisheng
在线教程
https://edu.csdn.net/course/detail/799
https://edu.csdn.net/course/detail/7471
联系方式
| 类型 | 内容 |
|---|---|
| 1004740957 | |
| 公众号 | lzugis15 |
| niujp08@qq.com | |
| webgisȺ | 452117357 |
| AndroidȺ | 337469080 |
| GIS数据可视化群 | 458292378 |
“GIS讲堂”知识星球今天开通了，在星球，我将提供一对一的问答服务，你问我答，期待与你相见。 
文章来源: geotools等值线生成