GeoJson的生成与解析，JSON解析，Java读写geojson，geotools读取shp文件，Geotools中Geometry对象与GeoJson的相互转换 |
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GeoJson的生成与解析，JSON解析，Java读写geojson，geotools读取shp文件，Geotools中Geometry对象与GeoJson的相互转换
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GeoJson的生成与解析
一、wkt格式的geometry转成json格式 二、json格式转wkt格式 三、json格式的数据进行解析 四、Java读写geojson 五、geotools读取shp文件 5.1 pom.xml 5.2 读取shp文件 六、Geotools中Geometry对象与GeoJson的相互转换 6.1 pom.xml import包 6.2 LineString–>geojson 6.3 geojson–>LineString 6.4 LineString转Feature 6.5 Feature转LineString 6.6 LineString转FeatureCollection 环境 gt-geojson-14.2.jar，json-simple-1.1.1.jar，jts-1.8.jar 一、wkt格式的geometry转成json格式 public String evaluate(String wkt) { String ret = null; try { Geometry geometry = reader.read(wkt); StringWriter writer = new StringWriter(); GeometryJSON g = new GeometryJSON(); g.write(geometry, writer); ret = writer.toString(); } catch (Exception e) { LOGGER.error(e.getMessage(), e); } return ret; } 二、json格式转wkt格式 public String evaluate(String geoJson) { String ret = null; GeometryJSON gjson = new GeometryJSON(); Reader reader = new StringReader(geoJson); try { Geometry geometry = gjson.read(reader); ret = geometry.toText(); } catch (IOException e) { LOGGER.error(e.getMessage(), e); } return ret; } 三、json格式的数据进行解析数据格式如下： { "_id" : "b454e650cb1a4fa4a2f2bd6899fbfa73", "bb" : "116.2451019,39.8486099,116.2451019,39.8486099", "pts" : [{ "1" : 0, "2" : 39.8486099, "3" : 116.2451019, "4" : 0.0, "5" : 0.0, "6" : "2012-03-07 14:25:08", "7" : "2012-03-07 14:25:10", "8" : "2", "9" : 0.0, "10" : 1 }, { "1" : 1, "2" : 39.8486099, "3" : 116.2451019, "4" : 0.0, "5" : 0.0, "6" : "2012-03-07 14:25:16", "7" : "2012-03-07 14:25:17", "8" : "1", "9" : 0.0, "10" : 1 }, { "1" : 2, "2" : 39.8486099, "3" : 116.2451019, "4" : -1.0, "5" : 0.0, "6" : "2012-03-07 14:25:18", "7" : "2012-03-07 14:25:20", "8" : "1", "9" : 0.0, "10" : 1 }] }获取“_id”值和“bb”属性值（两点的经纬度坐标），获取“pts”属性中第一个标签6的值（起始时间）和最后一个标签7的属性值（终止时间），并根据经纬度计算两点之间的距离，根据起始时间和终止时间计算其时间差，得到每个“_id”的对应的距离和时间差 private final double PI = 3.1415926; //圆周率 private final static double earthRadius = 6371; //地球半径，单位为KM public static void parseJson(BufferedReader bufferedReader) throws IOException, ParseException, java.text.ParseException{ String line = ""; //一行一行的形式读取文件 String[] pts6FirstTime =null;//第一个坐标点标签6的时间 String pts6Time =""; String ptsTime7 = ""; String reslut = ""; //计算最终结果 double betweenTime = 0.0d;//轨迹点之间的时间差，以小时（h）为单位 //longitude1、longitude2、dimension1、dimension2分别为经度坐标和维度坐标 double longitude1 = 0.0d; double dimension1 = 0.0d; double longitude2 = 0.0d; double dimension2 = 0.0d; //设置时间格式 DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); //创建json解析对象 JSONParser jsonParser = new JSONParser(); //创建一个distanceAndTime对象 DistanceAndTime distanceAndTime = new DistanceAndTime(); while((line = bufferedReader.readLine())!=null){ //开始解析 JSONObject jsonObject = (JSONObject)jsonParser.parse(line); String _id = (String) jsonObject.get("_id");//得到轨迹的id号 String bb = (String) jsonObject.get("bb");//得到轨迹的经纬度坐标bb //经纬度坐标是以","进行分割的 String[] longitudeDismension = bb.split(","); //Double.valueOf()把string类型转换为double类型 longitude1 = Double.valueOf(longitudeDismension[0]); dimension1 = Double.valueOf(longitudeDismension[1]); longitude2 = Double.valueOf(longitudeDismension[2]); dimension2 = Double.valueOf(longitudeDismension[3]); //计算具有经纬度的两坐标间的距离 double bbDistance = distanceAndTime. getDistance(longitude1, dimension1, longitude2, dimension2); //解析pts中的内容 JSONArray ptsjsonArray = (JSONArray)jsonObject.get("pts"); Iterator iterator = ptsjsonArray.iterator(); //解析pts中标签6的内容，并得到第一个标签6的内容 while(iterator.hasNext()){ JSONObject pts6JSONObject = (JSONObject)iterator.next(); pts6Time = pts6JSONObject.get("6").toString(); pts6FirstTime = pts6Time.split("\r\n"); break;//对于标签6的时间，只要第一个时间 } //解析pts中标签7的内容，并得到最后一个标签7的内容 while(iterator.hasNext()){ JSONObject pts7jsonobject = (JSONObject)iterator.next(); ptsTime7 = pts7jsonobject.get("7").toString(); } //计算轨迹的时间差，单位为小时（H） Date date1 = dateFormat.parse(ptsTime7); Date date2 = dateFormat.parse(pts6FirstTime[0]); betweenTime = (date1.getTime()-date2.getTime())/1000.0/3600.0; reslut = _id+"\t"+bbDistance+"\t"+betweenTime; writeToLocal(reslut); // System.out.println(reslut); } } //已知经纬度的轨迹点，计算两个轨迹点之间的距离，单位为KM public double getDistance(double longitude1,double dimension1,double longitude2,double dimension2){ double x,y,distance; x = (longitude1 - longitude2)*PI*earthRadius* Math.cos(((dimension1+dimension2)/2)*PI/180)/180; y = (dimension1-dimension2)*PI*earthRadius/180; distance = Math.hypot(x, y); return distance; } //计算结果输出 public static void writeToLocal(String string) throws IOException{ File outFile = new File("D://0820--Study//轨迹点数据//result.json"); if (!outFile.exists()) { outFile.createNewFile(); } //FileOutputStream设置为true，是为了后一条结果记录覆盖前一条结果记录 FileOutputStream fileOutputStream = new FileOutputStream(outFile,true); OutputStreamWriter outputStreamWriter = new OutputStreamWriter(fileOutputStream); BufferedWriter bufferedWriter = new BufferedWriter(outputStreamWriter); bufferedWriter.write(string); bufferedWriter.newLine(); bufferedWriter.flush(); bufferedWriter.close(); outputStreamWriter.close(); fileOutputStream.close(); } 四、Java读写geojson /** 读 **/ public Map getSiteMap() { Map map = new HashMap(); URL dataUrl = this.getClass().getClassLoader().getResource("public\\station.json"); // 259 try{ BufferedReader br =new BufferedReader(new FileReader(new File(dataUrl.toURI()))); String s = null; while((s = br.readLine()) != null){ // s 为原生的json串 // System.out.println("00=="+s); JSONObject jo = new JSONObject(s); // 创建一个包含原始json串的json对象 JSONArray features = jo.getJSONArray("features"); //找到features的json数组 for (int i = 0; i < features.length(); i++) { SiteEntity siteEntity = new SiteEntity(); JSONObject info = features.getJSONObject(i); // 获得features的第i个对象 JSONObject geometry = info.getJSONObject("geometry"); JSONObject properties = info.getJSONObject("properties"); siteEntity.setSite_stano(properties.getString("stano")); // 获得站名 List list = geometry.getJSONArray("coordinates").toList(); // 获得经纬度 siteEntity.setSite_longitude(Double.parseDouble(list.get(0).toString())); siteEntity.setSite_latitude(Double.parseDouble(list.get(1).toString())); // System.out.println(siteEntity.getSite_longitude()+"\n"+siteEntity.getSite_latitude()); map.put(i,siteEntity); } } }catch (Exception e){ e.printStackTrace(); } return map; } /**写**/ public void jsonOutPut(Map map) { ObjectMapper mapper = new ObjectMapper(); try{ mapper.writeValue(new File("D:/river-site.json"), map); }catch (Exception e){ e.printStackTrace(); } } 五、geotools读取shp文件 4.0.0 com.jjxliu.geotools geotools_t1 0.0.1-SNAPSHOT jar geotools_t1 http://maven.apache.org UTF-8 20-SNAPSHOT junit junit 4.11 test org.geotools gt-shapefile ${geotools.version} org.geotools gt-swing ${geotools.version} org.geotools gt-jdbc ${geotools.version} org.geotools.jdbc gt-jdbc-postgis ${geotools.version} org.geotools gt-epsg-hsql ${geotools.version} maven2-repository.dev.java.net Java.net repository http://download.java.net/maven/2 osgeo Open Source Geospatial Foundation Repository http://download.osgeo.org/webdav/geotools/ true boundless Boundless Maven Repository http://repo.boundlessgeo.com/main true org.apache.maven.plugins maven-compiler-plugin 1.8 1.8 public static SimpleFeatureCollection readShp(String path ){ return readShp(path, null); } public static SimpleFeatureCollection readShp(String path , Filter filter){ SimpleFeatureSource featureSource = readStoreByShp(path); if(featureSource == null) return null; try { return filter != null ? featureSource.getFeatures(filter) : featureSource.getFeatures() ; } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } return null ; } public static SimpleFeatureSource readStoreByShp(String path ){ File file = new File(path); FileDataStore store; SimpleFeatureSource featureSource = null; try { store = FileDataStoreFinder.getDataStore(file); ((ShapefileDataStore) store).setCharset(Charset.forName("UTF-8")); featureSource = store.getFeatureSource(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } return featureSource ; }测试一段读取的代码，打印所有读取到的simplefeature String path1 = "G:/work/china_map/shp/BOUNT_poly.shp" ; //读取shp SimpleFeatureCollection colls1 = readShp(path1); //拿到所有features SimpleFeatureIterator iters = colls1.features(); //遍历打印 while(iters.hasNext()){ SimpleFeature sf = iters.next(); System.out.println(sf.getID() + " , " + sf.getAttributes()); }
Geometry的子类主要有Point, LineString和Polygon. 基本操作类似。所以此处以LineString为例说明： // 由wkt字符串构造LineString对象 WKTReader reader = new WKTReader( geometryFactory ); LineString lineString = (LineString)reader.read("LINESTRING (254058.76074485347 475001.2186020431, 255351.04293761664 474966.9279243938)"); // 设置保留6位小数，否则GeometryJSON默认保留4位小数 GeometryJSON geometryJson = new GeometryJSON(6); StringWriter writer = new StringWriter(); geometryJson.write(lineString, writer); System.out.println(writer.toString()); writer.close(); LineString lineString = (LineString) geometryJson.read(new StringReader("{\n" + " \"type\": \"LineString\",\n" + " \"coordinates\": [\n" + " [\n" + " 120.6584555,\n" + " 30.45144\n" + " ],\n" + " [\n" + " 120.1654515,\n" + " 30.54848\n" + " ]\n" + " ]\n" + " }"));geojson还定义了带属性的Feature和表示Geometry对象集合的FeatureCollection，构造方法更加复杂，写两个示例备忘吧。 // geometry是必须的，其他属性可根据需求自定义，但是支持的类型有限，例如这个版本中double是不支持的，只支持float final SimpleFeatureType TYPE = DataUtilities.createType("Link", "geometry:LineString," + // |
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