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.xml5.2 读取shp文件 六、Geotools中Geometry对象与GeoJson的相互转换6.1 pom.xmlimport包6.2 LineString–>geojson6.3 geojson–>LineString6.4 LineString转Feature6.5 Feature转LineString6.6 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" : "-03-07 14:25:08","7" : "-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" : "-03-07 14:25:16","7" : "-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" : "-03-07 14:25:18","7" : "-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KMpublic 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KMpublic 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<Integer, SiteEntity> getSiteMap() {Map<Integer, SiteEntity> map = new HashMap<Integer, SiteEntity>();URL dataUrl = this.getClass().getClassLoader().getResource("public\\station.json"); // 259try{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

5.1 pom.xml

<project xmlns="/POM/4.0.0" xmlns:xsi="/2001/XMLSchema-instance"xsi:schemaLocation="/POM/4.0.0 /xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.jjxliu.geotools</groupId><artifactId>geotools_t1</artifactId><version>0.0.1-SNAPSHOT</version><packaging>jar</packaging><name>geotools_t1</name><url></url><properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><geotools.version>20-SNAPSHOT</geotools.version></properties><dependencies><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.11</version><scope>test</scope></dependency><dependency><groupId>org.geotools</groupId><artifactId>gt-shapefile</artifactId><version>${geotools.version}</version></dependency><dependency><groupId>org.geotools</groupId><artifactId>gt-swing</artifactId><version>${geotools.version}</version></dependency><dependency><groupId>org.geotools</groupId><artifactId>gt-jdbc</artifactId><version>${geotools.version}</version></dependency><dependency><groupId>org.geotools.jdbc</groupId><artifactId>gt-jdbc-postgis</artifactId><version>${geotools.version}</version></dependency><dependency><groupId>org.geotools</groupId><artifactId>gt-epsg-hsql</artifactId><version>${geotools.version}</version></dependency></dependencies><repositories><repository><id>maven2-repository.</id><name> repository</name><url>/maven/2</url></repository><repository><id>osgeo</id><name>Open Source Geospatial Foundation Repository</name><url>/webdav/geotools/</url></repository><repository><snapshots><enabled>true</enabled></snapshots><id>boundless</id><name>Boundless Maven Repository</name><url>/main</url></repository></repositories><build><plugins><plugin><inherited>true</inherited><groupId>org.apache.maven.plugins</groupId><artifactId>maven-compiler-plugin</artifactId><configuration><source>1.8</source><target>1.8</target></configuration></plugin></plugins></build></project>

5.2 读取shp文件

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 blocke.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 blocke.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shpSimpleFeatureCollection colls1 = readShp(path1);//拿到所有featuresSimpleFeatureIterator iters = colls1.features();//遍历打印while(iters.hasNext()){SimpleFeature sf = iters.next();System.out.println(sf.getID() + " , " + sf.getAttributes());}

六、Geotools中Geometry对象与GeoJson的相互转换

6.1 pom.xml

<geotools.version>17.1</geotools.version><!-- for geotools begin --><dependency><groupId>org.geotools</groupId><artifactId>gt-geojson</artifactId><version>${geotools.version}</version></dependency><!-- /artifact/org.geotools/gt-main --><dependency><groupId>org.geotools</groupId><artifactId>gt-main</artifactId><version>${geotools.version}</version></dependency><dependency><groupId>org.geotools</groupId><artifactId>gt-api</artifactId><version>${geotools.version}</version></dependency><dependency><groupId>org.geotools</groupId><artifactId>gt-opengis</artifactId><version>${geotools.version}</version></dependency><dependency><groupId>org.geotools</groupId><artifactId>gt-data</artifactId><version>${geotools.version}</version></dependency><dependency><groupId>org.geotools</groupId><artifactId>gt-referencing</artifactId><version>${geotools.version}</version></dependency><!--for geotools end-->

import包

import com.fasterxml.jackson.databind.ObjectMapper;import com.vividsolutions.jts.geom.*;import com.vividsolutions.jts.geom.Point;import com.vividsolutions.jts.io.ParseException;import com.vividsolutions.jts.io.WKTReader;import com.vividsolutions.jts.operation.linemerge.LineMerger;import org.geotools.data.DataUtilities;import org.geotools.feature.SchemaException;import org.geotools.feature.simple.SimpleFeatureBuilder;import org.geotools.geojson.feature.FeatureJSON;import org.geotools.geojson.geom.GeometryJSON;import org.geotools.geometry.jts.JTSFactoryFinder;import org.opengis.feature.simple.SimpleFeature;import org.opengis.feature.simple.SimpleFeatureType;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.beans.factory.annotation.Autowired;import org.ponent;import org.springframework.util.StringUtils;import java.io.IOException;import java.io.StringReader;import java.io.StringWriter;import java.util.*;

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：

6.2 LineString–>geojson

// 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();

6.3 geojson–>LineString

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。

6.4 LineString转Feature

// 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floatfinal SimpleFeatureType TYPE = DataUtilities.createType("Link","geometry:LineString," + // <- the geometry attribute: Point type"gid:String," + // <- a String attribute"direction:Integer," + // a number attribute"orientation:Integer");SimpleFeatureBuilder featureBuilder = new SimpleFeatureBuilder(TYPE);GeometryFactory geometryFactory = JTSFactoryFinder.getGeometryFactory();WKTReader reader = new WKTReader( geometryFactory );FeatureJSON fjson = new FeatureJSON();LineString lineString = (LineString)reader.read("LINESTRING (254058.76074485347 475001.2186020431, 255351.04293761664 474966.9279243938)");// 按照TYPE中声明的顺序为属性赋值就可以，其他方法我暂未尝试featureBuilder.add(lineString);featureBuilder.add("123456");featureBuilder.add(2);featureBuilder.add(0);SimpleFeature feature = featureBuilder.buildFeature(null);StringWriter writer = new StringWriter();fjson.writeFeature(feature, writer);System.out.println(writer.toString());

执行结果如下：

{“type”:”Feature”,”geometry”:{“type”:”LineString”,”coordinates”:[[254058.7607,475001.2186],[255351.0429,474966.9279]]},”properties”:{“gid”:”123456”,”direction”:2,”orientation”:0},”id”:”fid–5b8f258_15e04bda4b8_-8000”}

6.5 Feature转LineString

6.6 LineString转FeatureCollection

String[] WKTS = { "LINESTRING (255351.04293761664 474966.9279243938, 255529.29662365236 474272.4599921228)","LINESTRING (255529.29662365236 474272.4599921228, 256166.05830998957 473979.4498264)"};final SimpleFeatureType TYPE = DataUtilities.createType("Link","geometry:LineString," + // <- the geometry attribute: Point type"gid:String," + // <- a String attribute"direction:Integer," + // a number attribute"orientation:Integer");SimpleFeatureBuilder featureBuilder = new SimpleFeatureBuilder(TYPE);GeometryFactory geometryFactory = JTSFactoryFinder.getGeometryFactory();WKTReader reader = new WKTReader( geometryFactory );FeatureJSON fjson = new FeatureJSON();List<SimpleFeature> features = new ArrayList<>();SimpleFeatureCollection collection = new ListFeatureCollection(TYPE, features);for (String wkt : WKTS) {LineString lineString = (LineString)reader.read(wkt);featureBuilder.add(lineString);featureBuilder.add("123456");featureBuilder.add(2);featureBuilder.add(1);SimpleFeature feature = featureBuilder.buildFeature(null);features.add(feature);}StringWriter writer = new StringWriter();fjson.writeFeatureCollection(collection, writer);System.out.println(writer.toString());

打印结果如下：

{“type”:”FeatureCollection”,”features”:[{“type”:”Feature”,”geometry”:{“type”:”LineString”,”coordinates”:[[255351.0429,474966.9279],[255529.2966,474272.46]]},”properties”:{“gid”:”123456”,”direction”:2,”orientation”:1},”id”:”fid-67c46b85_15e0778dd81_-8000”},{“type”:”Feature”,”geometry”:{“type”:”LineString”,”coordinates”:[[255529.2966,474272.46],[256166.0583,473979.4492]]},”properties”:{“gid”:”123456”,”direction”:2,”orientation”:1},”id”:”fid-67c46b85_15e0778dd81_-7fff”}]}

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