jts

古城微笑少年丶 2022-05-27 11:55 179阅读 0赞

JTS基本概念和使用

# 简介 #

1.  JTS是加拿大的 Vivid Solutions公司做的一套开放源码的 Java API。它提供了一套空间数据操作的核心算法。为在兼容OGC标准的空间对象模型中进行基础的几何操作提供2D空间谓词API。

# 操作 #

1. 表示Geometry对象
 
 1. Geometry类型介绍见另一篇文章：[WKT WKB和GeoJSON][WKT WKB_GeoJSON]
 2. package com.alibaba.autonavi;
 
 
 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.Point;
 import com.vividsolutions.jts.geom.Polygon;
 import com.vividsolutions.jts.geom.MultiPolygon;
 import com.vividsolutions.jts.geom.MultiLineString;
 import com.vividsolutions.jts.geom.MultiPoint;
 import com.vividsolutions.jts.io.ParseException;
 import com.vividsolutions.jts.io.WKTReader;
 
 
 public class GeometryDemo {
 
 private GeometryFactory geometryFactory = new GeometryFactory();
 
 /**
 * create a point
 * @return
 */
 public Point createPoint(){
 Coordinate coord = new Coordinate(109.013388, 32.715519);
 Point point = geometryFactory.createPoint( coord );
 return point;
 }
 
 /**
 * create a point by WKT
 * @return
 * @throws ParseException 
 */
 public Point createPointByWKT() throws ParseException{
 WKTReader reader = new WKTReader( geometryFactory );
 Point point = (Point) reader.read("POINT (109.013388 32.715519)");
 return point;
 }
 
 /**
 * create multiPoint by wkt
 * @return
 */
 public MultiPoint createMulPointByWKT()throws ParseException{
 WKTReader reader = new WKTReader( geometryFactory );
 MultiPoint mpoint = (MultiPoint) reader.read("MULTIPOINT(109.013388 32.715519,119.32488 31.435678)");
 return mpoint;
 }
 /**
 * 
 * create a line
 * @return
 */
 public LineString createLine(){
 Coordinate[] coords = new Coordinate[] {
 new Coordinate(2, 2), new Coordinate(2, 2)};
 LineString line = geometryFactory.createLineString(coords);
 return line;
 }
 
 /**
 * create a line by WKT
 * @return
 * @throws ParseException
 */
 public LineString createLineByWKT() throws ParseException{
 WKTReader reader = new WKTReader( geometryFactory );
 LineString line = (LineString) reader.read("LINESTRING(0 0, 2 0)");
 return line;
 }
 
 /**
 * create multiLine 
 * @return
 */
 public MultiLineString createMLine(){
 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);
 LineString[] lineStrings = new LineString[2];
 lineStrings[0]= line1;
 lineStrings[1] = line2;
 MultiLineString ms = geometryFactory.createMultiLineString(lineStrings);
 return ms;
 }
 
 /**
 * create multiLine by WKT
 * @return
 * @throws ParseException
 */
 public MultiLineString createMLineByWKT()throws ParseException{
 WKTReader reader = new WKTReader( geometryFactory );
 MultiLineString line = (MultiLineString) reader.read("MULTILINESTRING((0 0, 2 0),(1 1,2 2))");
 return line;
 }
 
 /**
 * create a polygon(多边形) by WKT
 * @return
 * @throws ParseException
 */
 public Polygon createPolygonByWKT() throws ParseException{
 WKTReader reader = new WKTReader( geometryFactory );
 Polygon polygon = (Polygon) reader.read("POLYGON((20 10, 30 0, 40 10, 30 20, 20 10))");
 return polygon;
 }
 
 /**
 * create multi polygon by wkt
 * @return
 * @throws ParseException
 */
 public MultiPolygon createMulPolygonByWKT() throws ParseException{
 WKTReader reader = new WKTReader( geometryFactory );
 MultiPolygon mpolygon = (MultiPolygon) reader.read("MULTIPOLYGON(((40 10, 30 0, 40 10, 30 20, 40 10),(30 10, 30 0, 40 10, 30 20, 30 10)))");
 return mpolygon;
 }
 
 /**
 * create GeometryCollection contain point or multiPoint or line or multiLine or polygon or multiPolygon
 * @return
 * @throws ParseException
 */
 public GeometryCollection createGeoCollect() throws ParseException{
 LineString line = createLine();
 Polygon poly = createPolygonByWKT();
 Geometry g1 = geometryFactory.createGeometry(line);
 Geometry g2 = geometryFactory.createGeometry(poly);
 Geometry[] garray = new Geometry[]{g1,g2};
 GeometryCollection gc = geometryFactory.createGeometryCollection(garray);
 return gc;
 }
 
 /**
 * create a Circle 创建一个圆，圆心(x,y) 半径RADIUS
 * @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;
 }
 
 /**
 * @param args
 * @throws ParseException 
 */
 public static void main(String[] args) throws ParseException {
 GeometryDemo gt = new GeometryDemo();
 Polygon p = gt.createCircle(0, 1, 2);
 //圆上所有的坐标(32个)
 Coordinate coords[] = p.getCoordinates();
 for(Coordinate coord:coords){
 System.out.println(coord.x+","+coord.y);
 }
 }
 }
 
  
2. Geometry之间的关系
 
 1. 支持的空间操作包括

<table style="width:780px;margin:0px;background-color:rgb(255,255,255);padding:0px;color:rgb(0,0,0);font-family:Tahoma;font-size:14px;line-height:24px;"> 
 <tbody style="margin:0px;padding:0px;"> 
 <tr style="margin:0px;padding:0px;"> 
 <td style="padding:0px;margin:0px;">相等(Equals)：</td> 
 <td style="padding:0px;margin:0px;">几何形状拓扑上相等。</td> 
 </tr> 
 <tr style="margin:0px;padding:0px;"> 
 <td style="padding:0px;margin:0px;">脱节(Disjoint)：</td> 
 <td style="padding:0px;margin:0px;">几何形状没有共有的点。</td> 
 </tr> 
 <tr style="margin:0px;padding:0px;"> 
 <td style="padding:0px;margin:0px;">相交(Intersects)：</td> 
 <td style="padding:0px;margin:0px;">几何形状至少有一个共有点（区别于脱节）</td> 
 </tr> 
 <tr style="margin:0px;padding:0px;"> 
 <td style="padding:0px;margin:0px;">接触(Touches)：</td> 
 <td style="padding:0px;margin:0px;">几何形状有至少一个公共的边界点，但是没有内部点。</td> 
 </tr> 
 <tr style="margin:0px;padding:0px;"> 
 <td style="padding:0px;margin:0px;">交叉(Crosses)：</td> 
 <td style="padding:0px;margin:0px;">几何形状共享一些但不是所有的内部点。</td> 
 </tr> 
 <tr style="margin:0px;padding:0px;"> 
 <td style="padding:0px;margin:0px;">内含(Within)：</td> 
 <td style="padding:0px;margin:0px;">几何形状A的线都在几何形状B内部。</td> 
 </tr> 
 <tr style="margin:0px;padding:0px;"> 
 <td style="padding:0px;margin:0px;">包含(Contains)：</td> 
 <td style="padding:0px;margin:0px;">几何形状B的线都在几何形状A内部（区别于内含）</td> 
 </tr> 
 <tr style="margin:0px;padding:0px;"> 
 <td style="padding:0px;margin:0px;">重叠(Overlaps)：</td> 
 <td style="padding:0px;margin:0px;">几何形状共享一部分但不是所有的公共点，而且相交处有他们自己相同的区域。</td> 
 </tr> 
 </tbody> 
</table>

package com.alibaba.autonavi;
    
    import com.vividsolutions.jts.geom.*;
    import com.vividsolutions.jts.io.ParseException;
    import com.vividsolutions.jts.io.WKTReader;
    
    /**
     * gemotry之间的关系
     * @author xingxing.dxx
     *
     */
    public class GeometryRelated {
    
        private GeometryFactory geometryFactory = new GeometryFactory();
        
        /**
         *  两个几何对象是否是重叠的
         * @return
         * @throws ParseException
         */
        public boolean equalsGeo() throws ParseException{
            WKTReader reader = new WKTReader( geometryFactory );
            LineString geometry1 = (LineString) reader.read("LINESTRING(0 0, 2 0, 5 0)");
            LineString geometry2 = (LineString) reader.read("LINESTRING(5 0, 0 0)");
            return geometry1.equals(geometry2);//true
        }
        
        /**
         * 几何对象没有交点(相邻)
         * @return
         * @throws ParseException
         */
        public boolean disjointGeo() throws ParseException{
            WKTReader reader = new WKTReader( geometryFactory );
            LineString geometry1 = (LineString) reader.read("LINESTRING(0 0, 2 0, 5 0)");
            LineString geometry2 = (LineString) reader.read("LINESTRING(0 1, 0 2)");
            return geometry1.disjoint(geometry2);
        }
        
        /**
         * 至少一个公共点(相交)
         * @return
         * @throws ParseException
         */
        public boolean intersectsGeo() throws ParseException{
            WKTReader reader = new WKTReader( geometryFactory );
            LineString geometry1 = (LineString) reader.read("LINESTRING(0 0, 2 0, 5 0)");
            LineString geometry2 = (LineString) reader.read("LINESTRING(0 0, 0 2)");
            Geometry interPoint = geometry1.intersection(geometry2);//相交点
            System.out.println(interPoint.toText());//输出 POINT (0 0)
            return geometry1.intersects(geometry2);
        }
    
        /**
         * 判断以x,y为坐标的点point(x,y)是否在geometry表示的Polygon中
         * @param x
         * @param y
         * @param geometry wkt格式
         * @return
         */
        public boolean withinGeo(double x,double y,String geometry) throws ParseException {
    
            Coordinate coord = new Coordinate(x,y);
            Point point = geometryFactory.createPoint( coord );
    
            WKTReader reader = new WKTReader( geometryFactory );
            Polygon polygon = (Polygon) reader.read(geometry);
            return point.within(polygon);
        }
        /**
         * @param args
         * @throws ParseException 
         */
        public static void main(String[] args) throws ParseException {
            GeometryRelated gr = new GeometryRelated();
            System.out.println(gr.equalsGeo());
            System.out.println(gr.disjointGeo());
            System.out.println(gr.intersectsGeo());
            System.out.println(gr.withinGeo(5,5,"POLYGON((0 0, 10 0, 10 10, 0 10,0 0))"));
        }
    
    }

[WKT WKB_GeoJSON]: http://www.cnblogs.com/duanxingxing/p/5144257.html