简介
- 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
- 表示Geometry对象
- Geometry类型介绍见另一篇文章：WKT WKB和GeoJSON
-
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); } } }
- Geometry之间的关系
- 支持的空间操作包括
|
相等(Equals)： |
几何形状拓扑上相等。 |
|
脱节(Disjoint)： |
几何形状没有共有的点。 |
|
相交(Intersects)： |
几何形状至少有一个共有点（区别于脱节） |
|
接触(Touches)： |
几何形状有至少一个公共的边界点，但是没有内部点。 |
|
交叉(Crosses)： |
几何形状共享一些但不是所有的内部点。 |
|
内含(Within)： |
几何形状A的线都在几何形状B内部。 |
|
包含(Contains)： |
几何形状B的线都在几何形状A内部（区别于内含） |
|
重叠(Overlaps)： |
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。 |
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))"));
}
}
时间： 2024-10-29 10:46:22