Java Web+GeoTools工具+自定义几何对象构造器+简单应用

基于上一篇继续讲

一、相关依赖【不知道的继续看一遍】

（1）

<!-- 使用Java8，嘗試使用新特新【stream和lambda】 --><properties><java.version>1.8</java.version><geotools.version>17.0</geotools.version><postgresql.version>42.1.4</postgresql.version></properties><repositories><repository><id>osgeo</id><name>Open Source Geospatial Foundation Repository</name><url>http://download.osgeo.org/webdav/geotools/</url></repository></repositories>

（2）

<!-- 添加GeoTools依赖 --><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><!-- 添加geotools-jdbc --><dependency><groupId>org.geotools.jdbc</groupId><artifactId>gt-jdbc-postgis</artifactId><version>${geotools.version}</version></dependency><!-- postgresql --><dependency><groupId>org.postgresql</groupId><artifactId>postgresql</artifactId></dependency>

二、PostGis空间几何对象构造器

（1）GeometryCreator.java

package com.appleyk.geotools;import java.util.List;import com.vividsolutions.jts.geom.Coordinate;import com.vividsolutions.jts.geom.Geometry;import com.vividsolutions.jts.geom.GeometryCollection;import com.vividsolutions.jts.geom.GeometryFactory;import com.vividsolutions.jts.geom.LineString;import com.vividsolutions.jts.geom.LinearRing;import com.vividsolutions.jts.geom.MultiLineString;import com.vividsolutions.jts.geom.MultiPoint;import com.vividsolutions.jts.geom.MultiPolygon;import com.vividsolutions.jts.geom.Point;import com.vividsolutions.jts.geom.Polygon;import com.vividsolutions.jts.io.ParseException;import com.vividsolutions.jts.io.WKTReader;/** * 几何对象构建器 *  * @author  [e-mail] * @blob    http://blog.csdn.net/appleyk * @version V1.0.1 * @date    2017年12月8日10:38:49 *///单例模式public class GeometryCreator {public static GeometryCreator geometryCreator = null; private GeometryFactory geometryFactory = new GeometryFactory();private GeometryCreator() {}/** * 返回本类的唯一实例 * @return */public static GeometryCreator getInstance() {if (geometryCreator == null) {return new GeometryCreator();}return geometryCreator;}/** * 1.构建点 *//** * 1.1根据X，Y坐标构建一个几何对象： 点 【Point】 * @param x * @param y * @return */public Point createPoint(double x,double y){            Coordinate coord = new Coordinate(x, y);            Point point = geometryFactory.createPoint(coord);            return point;        }   /** * 1.2根据几何对象的WKT描述【String】创建几何对象： 点 【Point】 * @return * @throws ParseException */public Point createPointByWKT(String PointWKT) throws ParseException{            WKTReader reader = new WKTReader(geometryFactory);            Point point = (Point) reader.read(PointWKT);            return point;        }   /** * 1.3根据几何对象的WKT描述【String】创建几何对象：多点 【MultiPoint】 * @return * @throws ParseException */public MultiPoint createMulPointByWKT(String MPointWKT)throws ParseException{            WKTReader reader = new WKTReader( geometryFactory );            MultiPoint mpoint = (MultiPoint) reader.read(MPointWKT);            return mpoint;        }   /** * 2.构建线 *//** * 2.1根据两点 创建几何对象：线 【LineString】 * @param ax * @param ay * @param bx * @param by * @return */public LineString createLine(double ax,double ay,double bx,double by){            Coordinate[] coords  = new Coordinate[] {new Coordinate(ax, ay), new Coordinate(bx, by)};            LineString line = geometryFactory.createLineString(coords);            return line;        }    /** * 2.2根据线的WKT描述创建几何对象：线 【LineString】 * @param LineStringWKT * @return * @throws ParseException */    public LineString createLineByWKT(String LineStringWKT) throws ParseException{            WKTReader reader = new WKTReader( geometryFactory );            LineString line = (LineString) reader.read("LINESTRING(0 0, 2 0)");            return line;        }            /**     * 2.3根据点组合的线数组，创建几何对象：多线 【MultiLineString】     * @param list     * @return     */    public MultiLineString createMLine(List<Coordinate[]> list){            MultiLineString ms = null;            if(list == null){    return ms;    }        LineString[] lineStrings = new LineString[list.size()];                //      Coordinate[] coords1  = new Coordinate[] {new Coordinate(2, 2), new Coordinate(2, 2)};    //      LineString line1 = geometryFactory.createLineString(coords1);    //       //      Coordinate[] coords2  = new Coordinate[] {new Coordinate(2, 2), new Coordinate(2, 2)};    //      LineString line2 = geometryFactory.createLineString(coords2);                    int i = 0;    for (Coordinate[] coordinates : list) {lineStrings[i] = geometryFactory.createLineString(coordinates);}                   ms = geometryFactory.createMultiLineString(lineStrings);                    return ms;        }              /**     * 2.4根据几何对象的WKT描述【String】创建几何对象 ： 多线【MultiLineString】     * @param MLineStringWKT     * @return     * @throws ParseException     */    public MultiLineString createMLineByWKT(String MLineStringWKT)throws ParseException{            WKTReader reader = new WKTReader( geometryFactory );            MultiLineString line = (MultiLineString) reader.read(MLineStringWKT);            return line;        }                   /**     * 3.构建多边形     */        /**     * 3.1 根据几何对象的WKT描述【String】创建几何对象：多边形 【Polygon】     * @param PolygonWKT     * @return     * @throws ParseException     */    public Polygon createPolygonByWKT(String PolygonWKT) throws ParseException{            WKTReader reader = new WKTReader( geometryFactory );            Polygon polygon = (Polygon) reader.read(PolygonWKT);            return polygon;        }            /**     * 3.2 根据几何对象的WKT描述【String】创建几何对象： 多多边形 【MultiPolygon】     * @param MPolygonWKT     * @return     * @throws ParseException     */    public MultiPolygon createMulPolygonByWKT(String MPolygonWKT) throws ParseException{            WKTReader reader = new WKTReader( geometryFactory );            MultiPolygon mpolygon = (MultiPolygon) reader.read(MPolygonWKT);            return mpolygon;        }             /**     * 4.构建几何对象集合     */        /**     * 4.1 根据几何对象数组，创建几何对象集合：【GeometryCollection】     * @return     * @throws ParseException     */    public GeometryCollection createGeoCollect(Geometry[] geoArray) throws ParseException{    //            LineString line = createLine(125.12,25.4,85.63,99.99);    //            Polygon poly    =  createPolygonByWKT("POLYGON((20 10, 30 0, 40 10, 30 20, 20 10))");    //            Geometry g1     = geometryFactory.createGeometry(line);    //            Geometry g2     = geometryFactory.createGeometry(poly);    //            Geometry[] geoArray = new Geometry[]{g1,g2};                GeometryCollection gc = geometryFactory.createGeometryCollection(geoArray);                return gc;            }             /**     * 5.构建圆     */        /**     * 5.1 根据圆点以及半径创建几何对象：特殊的多边形--圆 【Polygon】     * @param x     * @param y     * @param RADIUS     * @return     */    public Polygon createCircle(double x, double y, final double RADIUS){              final int SIDES = 32;//圆上面的点个数                    Coordinate coords[] = new Coordinate[SIDES+1];            for( int i = 0; i < SIDES; i++){                double angle = ((double) i / (double) SIDES) * Math.PI * 2.0;                double dx = Math.cos( angle ) * RADIUS;                double dy = Math.sin( angle ) * RADIUS;                coords[i] = new Coordinate( (double) x + dx, (double) y + dy );            }            coords[SIDES] = coords[0];            LinearRing ring = geometryFactory.createLinearRing(coords);            Polygon polygon = geometryFactory.createPolygon(ring, null);            return polygon;        }           }

 (2)什么是WKT呢？

数据库 ：【postgresql】

我们看一下，国家大剧院这个建筑物，在空间数据库的表中几的何形态的数据信息是什么，是什么类型

我们看下geom这个字段的类型

那我们怎么读取这个几何对象实际表示的空间信息呢？

三、空间数据库的简单操作+shapfile文件的读写应用

（1）GTDataBase.java

package com.appleyk.geotools;import java.io.File;import java.io.IOException;import java.io.Serializable;import java.nio.charset.Charset;import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.Statement;import java.util.ArrayList;import java.util.Collection;import java.util.HashMap;import java.util.Iterator;import java.util.List;import java.util.Map;import org.geotools.data.DataStore;import org.geotools.data.DataStoreFinder;import org.geotools.data.FeatureSource;import org.geotools.data.FeatureWriter;import org.geotools.data.Transaction;import org.geotools.data.postgis.PostgisNGDataStoreFactory;import org.geotools.data.shapefile.ShapefileDataStore;import org.geotools.data.shapefile.ShapefileDataStoreFactory;import org.geotools.data.shapefile.files.ShpFiles;import org.geotools.data.shapefile.shp.ShapefileReader;import org.geotools.feature.FeatureCollection;import org.geotools.feature.FeatureIterator;import org.geotools.feature.simple.SimpleFeatureTypeBuilder;import org.geotools.referencing.crs.DefaultGeographicCRS;import org.opengis.feature.Property;import org.opengis.feature.simple.SimpleFeature;import org.opengis.feature.simple.SimpleFeatureType;import com.appleyk.pojo.Geometry;import com.vividsolutions.jts.geom.GeometryFactory;import com.vividsolutions.jts.geom.MultiPolygon;import com.vividsolutions.jts.geom.Polygon;public class GTDataBase {static Connection connection = null;static DataStore pgDatastore = null;@SuppressWarnings("rawtypes")static FeatureSource fSource = null;static Statement statement   = null ; static GeometryCreator gCreator = GeometryCreator.getInstance();/** * 1.连接postgrepsql数据库 *  * @param ip * @param port * @param user * @param password * @param database * @return * @throws Exception */private static boolean ConnDataBase(String ip, Integer port, String user, String password, String database)throws Exception {// "jdbc:postgresql://192.168.1.104:5432/test"// user=postgres// password=bluethink134// 拼接urlString url = "jdbc:postgresql://" + ip + ":" + port + "/" + database;Class.forName("org.postgresql.Driver"); // 一定要注意和上面的MySQL语法不同connection = DriverManager.getConnection(url, user, password);if (connection != null) {return true;} else {return false;}}/** * 2.连接数据库 使用的postgis 链接代码如下： *  * @param dbtype * @param host * @param port * @param database * @param userName * @param password */private static void ConnPostGis(String dbtype, String host, int port, String database, String userName,String password) {Map<String, Object> params = new HashMap<String, Object>();params.put(PostgisNGDataStoreFactory.DBTYPE.key, dbtype);params.put(PostgisNGDataStoreFactory.HOST.key, host);params.put(PostgisNGDataStoreFactory.PORT.key, new Integer(port));params.put(PostgisNGDataStoreFactory.DATABASE.key, database);params.put(PostgisNGDataStoreFactory.SCHEMA.key, "public");params.put(PostgisNGDataStoreFactory.USER.key, userName);params.put(PostgisNGDataStoreFactory.PASSWD.key, password);try {pgDatastore = DataStoreFinder.getDataStore(params);if (pgDatastore != null) {System.out.println("系统连接到位于：" + host + "的空间数据库" + database + "成功！");} else {System.out.println("系统连接到位于：" + host + "的空间数据库" + database + "失败！请检查相关参数");}} catch (IOException e) {e.printStackTrace();System.out.println("系统连接到位于：" + host + "的空间数据库" + database + "失败！请检查相关参数");}}// 3.针对某个地理图层，进行地理信息的读取@SuppressWarnings("unchecked")public static void PostGisReading(String Schema) throws Exception {fSource = pgDatastore.getFeatureSource(Schema);// 一个用于处理FeatureCollection的实用工具类。提供一个获取FeatureCollection实例的机制FeatureCollection<SimpleFeatureType, SimpleFeature> result = fSource.getFeatures();// 计算本图层中所有特征的数量//System.out.println(result.size());//1.迭代特征FeatureIterator<SimpleFeature> iterator = result.features();//迭代 特征  只迭代30个 太大了，一下子迭代完，非常耗时int stop = 0;while(iterator.hasNext()){if(stop >30){break;}SimpleFeature feature = iterator.next();Collection<Property> p = feature.getProperties();Iterator<Property> it  = p.iterator();//2.特征里面的属性再迭代,属性里面有字段System.out.println("================================");while(it.hasNext()){Property pro = it.next();System.out.println(pro.getName()+"\t = "+pro.getValue());}//end 里层whilestop++;}//end 最外层 whileiterator.close();}/**4.Insert * 插入一条特征 * @param geo * @return * @throws Exception */public static boolean Insert(Geometry geo) throws Exception{        boolean result = false;String sql = "insert into geotable (osm_id,code,fclass,name,type,geom) values('"+geo.getOsm_id()+"','"+geo.getCode()+"','"+geo.getFclass()+"','"+geo.getName()+"','"+geo.getType()+"',"+"st_geomfromewkt('"+geo.getGeom().toString()+"'))";PreparedStatement pstmt;pstmt = connection.prepareStatement(sql);     //geometry = st_geomfromewkt(text WKT)//System.out.println(sql);int i = pstmt.executeUpdate();  if(i>0){result = true;}        pstmt.close();                  return result;}// 4.取得POSTGIS中所有的地理图层public static void getAllLayers() throws Exception {String[] typeName = pgDatastore.getTypeNames();for (int i = 0; i < typeName.length; i++) {System.out.println((i + 1) + ":" + typeName[i]);}}//2.3个文件一起读，以Point为例,读取后插入数据表public static void ReadSHP(String path) throws Exception{//A.建筑物的shapefile，多边形 MULTIPOLYGON//String path = "E:\\china-latest-free\\gis.osm_buildings_a_free_1.shp";//B.路的shapefile，多线MULTILINESTRING//String path = "E:\\china-latest-free\\gis.osm_roads_free_1.shp";//C.建筑物的点坐标  以Point为主//String path = "E:\\china-latest-free\\gis.osm_pois_free_1.shp";//一个数据存储实现，允许从Shapefiles读取和写入ShapefileDataStore shpDataStore = null;shpDataStore = new ShapefileDataStore(new File(path).toURI().toURL());shpDataStore.setCharset(Charset.forName("UTF-8"));//获取这个数据存储保存的类型名称数组//getTypeNames:获取所有地理图层String typeName = shpDataStore.getTypeNames()[0];//通过此接口可以引用单个shapefile、数据库表等。与数据存储进行比较和约束FeatureSource<SimpleFeatureType, SimpleFeature> featureSource = null;featureSource = (FeatureSource<SimpleFeatureType, SimpleFeature>)shpDataStore.getFeatureSource(typeName);//一个用于处理FeatureCollection的实用工具类。提供一个获取FeatureCollection实例的机制FeatureCollection<SimpleFeatureType, SimpleFeature> result=featureSource.getFeatures();//System.out.println(result.size());FeatureIterator<SimpleFeature> iterator = result.features();//迭代 特征  只迭代30个 太大了，一下子迭代完，非常耗时int stop = 0;List<Geometry> geolist = new ArrayList<>();while(iterator.hasNext()){if(stop >100){break;}SimpleFeature feature = iterator.next();Collection<Property> p = feature.getProperties();Iterator<Property> it  = p.iterator();Geometry geo = new Geometry();//特征里面的属性再迭代,属性里面有字段String name;while(it.hasNext()){Property pro = it.next();name= pro.getName().toString();if(name.equals("the_geom")){geo.setGeom(pro.getValue());}if(name.equals("osm_id")){geo.setOsm_id(pro.getValue().toString());}if(name.equals("code")){geo.setCode(Integer.parseInt(pro.getValue().toString()));}if(name.equals("fclass")){geo.setFclass(pro.getValue().toString());}if(name.equals("name")){geo.setName(pro.getValue().toString());}if(name.equals("type")){geo.setType(pro.getValue().toString());}}//end 里层whilegeolist.add(geo);stop++;}//end 最外层 whileiterator.close();boolean bRes = true;for (Geometry geo : geolist) {//System.out.println("================================");//    System.out.println(geo.getCode());//    System.out.println(geo.getFclass());//    System.out.println(geo.getGid());//    System.out.println(geo.getName());//    System.out.println(geo.getOsm_id());//System.out.println(geo.getFclass());if(!Insert(geo)){bRes = false;break;}}if(bRes){System.out.println("读取shapefile文件内容插入数据库成功！");}}/** * 将几何对象信息写入一个shapfile文件 * @throws Exception */public static void WriteSHP(String path) throws Exception{//String path="C:\\my.shp";//1.创建shape文件对象File file =new File(path);Map<String, Serializable> params = new HashMap<>();//用于捕获参数需求的数据类//URLP:url to the .shp file. params.put(ShapefileDataStoreFactory.URLP.key, file.toURI().toURL());//2.创建一个新的数据存储——对于一个还不存在的文件。ShapefileDataStore ds = (ShapefileDataStore) new ShapefileDataStoreFactory().createNewDataStore(params);//3.定义图形信息和属性信息//SimpleFeatureTypeBuilder 构造简单特性类型的构造器SimpleFeatureTypeBuilder tBuilder = new SimpleFeatureTypeBuilder();//设置//WGS84:一个二维地理坐标参考系统，使用WGS84数据tBuilder.setCRS(DefaultGeographicCRS.WGS84);tBuilder.setName("shapefile");//添加 一个几何对象：特殊的多边形：圆tBuilder.add("the_geom", Polygon.class);//添加一个idtBuilder.add("osm_id", Long.class);//添加名称tBuilder.add("name", String.class);//添加描述tBuilder.add("des", String.class);//设置此数据存储的特征类型ds.createSchema(tBuilder.buildFeatureType());//设置编码ds.setCharset(Charset.forName("UTF-8"));//设置writer//为给定的类型名称创建一个特性写入器//1.typeName：特征类型//2.transaction :事物,写入失败，回滚//3.ShapefileDataStore::getTypeNames:/*public String[] getTypeNames() 获取这个数据存储保存的类型名称数组。ShapefileDataStore总是返回一个名称*/FeatureWriter<SimpleFeatureType, SimpleFeature> writer = ds.getFeatureWriter(ds.getTypeNames()[0], Transaction.AUTO_COMMIT);//Interface SimpleFeature：一个由固定列表值以已知顺序组成的SimpleFeatureType实例。//写一个点SimpleFeature feature = writer.next();//SimpleFeature ::setAttribute(String attrName, Object val)//给指定的属性名称添加一个对象 POINTdouble x = 116.123; //X轴坐标double y = 39.345 ; //Y轴坐标/* * Coordinate : GeoAPI几何接口的实现 一个轻量级的类，用于存储二维笛卡尔平面上的坐标。 它不同于点，它是几何的一个子类。 不同于类型点的对象(包含额外的信息，如信封、精确模型和空间引用系统信息)， 坐标只包含有序值和访问方法。 *///Coordinate coordinate = new Coordinate(x, y);//GeometryFactory:提供一套实用的方法，用于从坐标列表中构建几何对象。//构造一个几何图形工厂，生成具有浮动精度模型的几何图形和一个0的空间引用ID。//Point point = new GeometryFactory().createPoint(coordinate);//feature.setAttribute("the_geom",polygon);//feature.setAttribute("osm_id", 1234567890l);//feature.setAttribute("name", "帅鱼");//feature.setAttribute("des", "爱宝宝");//利用几何对象构造器创建一个圆Polygon polygon = gCreator.createCircle(x, y, 20);feature.setAttribute("the_geom",polygon);feature.setAttribute("osm_id", 1234567890l);feature.setAttribute("name", "太阳");feature.setAttribute("des", "一个半径等于20的圆");//再来一个点////feature = writer.next();////x = 116.456;//y = 39.678 ;//    coordinate = new Coordinate(x, y);//point = new GeometryFactory().createPoint(coordinate);////feature.setAttribute("the_geom",point);//feature.setAttribute("osm_id", 1234567891l);//feature.setAttribute("name", "宝宝");//feature.setAttribute("des", "爱帅鱼");//写入writer.write();//关闭writer.close();//释放资源ds.dispose();//读取shapefile文件的图形信息ShpFiles shpFiles = new ShpFiles(path);/*ShapefileReader( ShpFiles shapefileFiles, boolean strict, --是否是严格的、精确的 boolean useMemoryMapped,--是否使用内存映射 GeometryFactory gf,     --几何图形工厂 boolean onlyRandomAccess--是否只随机存取 )*/ShapefileReader reader = new ShapefileReader(shpFiles,false, true, new GeometryFactory(), false);while(reader.hasNext()){System.out.println(reader.nextRecord().shape());}reader.close();}/** * 3.根据几何对象名称 查询几何对象信息 [Query] * @param name * @throws Exception */public static void Query(String name) throws Exception{//String sql = "select st_astext(geom) from geotable where name ='"+name+"'";String sql = "select  st_geometrytype(geom) as type,st_astext(geom) as geom from geotable where name ='"+name+"'";statement = connection.createStatement();ResultSet result = statement.executeQuery(sql);if(result!=null){while(result.next()){Object val = result.getString(1);if(val.equals("ST_MultiPolygon")){System.out.println("几何对象类型：多多边形");MultiPolygon mPolygon = gCreator.createMulPolygonByWKT(result.getString(2));System.out.println(mPolygon instanceof MultiPolygon);System.out.println("获取几何对象中的点个数："+mPolygon.getNumPoints());}}}}// Main 方法测试public static void main(String[] args) throws Exception {//1.利用Provider连接 空间数据库if (!ConnDataBase("192.168.1.104", 5432, "postgres", "123456", "test")) {System.out.println("连接postgresql数据库失败，请检查参数！");}ConnPostGis("postgis", "192.168.1.104", 5432, "test", "postgres", "123456");String path = "E:\\china-latest-free\\gis.osm_buildings_a_free_1.shp";//2.读shapfile文件，并将内容写入空间数据库//ReadSHP(path);//3.获得空间数据库中所有的  地理图层getAllLayers();//4.根据空间几何对象的名称 查询几何对象信息Query("国家大剧院");//5.创建一个圆【多边形】，并写入shapfile文件WriteSHP("C:\\Sun\\sun.shp");}}

(2)读取shapfile文件并写入空间数据库【所谓的空间数据库就是postgresql数据库加了postgis扩展】

选择数据库，执行下面的语句，就会把当前的数据库"变成"空间数据库

CREATE EXTENSION postgis

执行后，原本的数据库下面，自动多出一张表

（3）geotable表创建的sql脚本

DROP TABLE IF EXISTS "public"."geotable";CREATE TABLE "public"."geotable" ("gid" int4 DEFAULT nextval('geo_seq'::regclass) NOT NULL,"osm_id" varchar(10) COLLATE "default","code" int2,"fclass" varchar(20) COLLATE "default","name" varchar(100) COLLATE "default","type" varchar(20) COLLATE "default","geom" "public"."geometry")WITH (OIDS=FALSE);

其中基于gid标识的序列是

（4）由于geotable已经插入数据了，代码里就给注释掉了

（5）运行Main方法，测试读取、查询和创建一个shapfile文件

A.

B.我们去这个路径下面，看一下我们的shapfile文件是否创建

C.

D.利用上一篇里面的内容，打开这个shp文件

E.利用空间范围查询几何对象集合【留个悬念】

补充说明：也就是在一个空间范围内，有哪些路，哪些建筑物，哪些物体等

几何对象存取函数：

获取几何对象的WKT描述 ST_AsText(geometry)
获取几何对象的WKB描述ST_AsBinary(geometry)
获取几何对象的空间参考ID ST_SRID(geometry)
获取几何对象的维数ST_Dimension(geometry)
获取几何对象的边界范围ST_Envelope(geometry)
判断几何对象是否为空 ST_IsEmpty(geometry)
判断几何对象是否不包含特殊点（比如自相交）ST_IsSimple(geometry)
判断几何对象是否闭合ST_IsClosed(geometry)
判断曲线是否闭合并且不包含特殊点 ST_IsRing(geometry)
获取多几何对象中的对象个数ST_NumGeometries(geometry)
获取多几何对象中第N个对象ST_GeometryN(geometry,int)
获取几何对象中的点个数ST_NumPoints(geometry)
获取几何对象的第N个点ST_PointN(geometry,integer)
获取多边形的外边缘ST_ExteriorRing(geometry)
获取多边形内边界个数ST_NumInteriorRings(geometry)
同上ST_NumInteriorRing(geometry)
获取多边形的第N个内边界ST_InteriorRingN(geometry,integer)
获取线的终点ST_EndPoint(geometry)
获取线的起始点 ST_StartPoint(geometry)
获取几何对象的类型GeometryType(geometry)
类似上，但是不检查M值，即POINTM对象会被判断为pointST_GeometryType(geometry)
获取点的X坐标 ST_X(geometry)
获取点的Y坐标 ST_Y(geometry)
获取点的Z坐标 ST_Z(geometry)
获取点的M值 ST_M(geometry)

本篇完！