JTS Geometry之间的关系.doc

JTS(Geometry)空间数据模型(1)、JTS Geometry model (2)、ISO Geometry model (Geometry Plugin and JTS Wrapper Plugin)GeoTools has two implementations of these interfaces:Geometry Plugin a port of JTS 1.7 to the ISO Geometry interfacesJTS Wrapper Plugin an implementation that delegates all the work to JTSJTS包结构系（linearref包）、计算交点（noding包）、几何图形操作（operation包）、平面图（planargraph包）、多边形化（polygnize包）、精度（precision）、工具（util包）重点理解JTS Geometry model(1) JTS提供了如下的空间数据类型 Point MultiPoint LineString LinearRing 封闭的线条 MultiLineString 多条线 Polygon MultiPolygon GeometryCollection 包括点，线，面(2) 支持接口Coordinate Coordinate（坐标）是用来存储坐标的轻便的类。它不同于点，点是Geometry的子类。不像模范Point的对象（包含额外的信息，例如一个信包，一个精确度模型和空间参考系统信息），Coordinate只包含纵座标值和存取方法。Envelope(矩形) 一个具体的类，包含一个最大和最小的x 值和y 值。GeometryFactory GeometryFactory提供一系列的有效方法用来构造来自Coordinate类的Geometry对象。支持接口java view plain copypackage com.mapbar.geo.jts; import org.geotools.geometry.jts.JTSFactoryFinder; 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; /* * Class GeometryDemo.java * Description Geometry 几何实体的创建，读取操作 * Company mapbar * author Chenll E-mail: C * Version 1.0 * Date 2012-2-17 上午11:08:50 */ public class GeometryDemo private GeometryFactory geometryFactory = JTSFactoryFinder.getGeometryFactory( null ); /* * 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 ); MultiPointmpoint=(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 LineString2; lineStrings0= line1; lineStrings1 = 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 Geometryg1,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 CoordinateSIDES+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; coordsi = new Coordinate( (double) x + dx, (double) y + dy ); coordsSIDES = coords0; LinearRing ring = geometryFactory.createLinearRing( coords ); Polygon polygon = geometryFactory.createPolygon( ring, null ); return polygon; /* * pa