我有这段代码,它在地图上绘制一个线串,它是用户提供的 2 个坐标点的轨迹。
public class Quickstart {
public static void main(String[] args) throws Exception {
// display a data store file chooser dialog for shapefiles
File file = JFileDataStoreChooser.showOpenFile("shp", null);
if (file == null) {
return;
}
FileDataStore store = FileDataStoreFinder.getDataStore(file);
SimpleFeatureSource featureSource = store.getFeatureSource();
GeometryFactory gf = JTSFactoryFinder.getGeometryFactory();
double latitude, longitude, latitudeDest, longitudeDest;
Scanner reader = new Scanner(System.in);
reader.useLocale(Locale.US);
System.out.println("Enter reference longitude and latitude:\n");
longitude = reader.nextDouble();
latitude = reader.nextDouble();
System.out.println("Enter destination longitude and latitude:\n");
longitudeDest = reader.nextDouble();
latitudeDest = reader.nextDouble();
reader.close();
final String EPSG4326 = "GEOGCS[\"WGS 84\",DATUM[\"WGS_1984\",SPHEROID[\"WGS 84\",6378137,298.257223563,AUTHORITY[\"EPSG\"," +
"\"7030\"]],AUTHORITY[\"EPSG\",\"6326\"]],PRIMEM[\"Greenwich\",0,AUTHORITY[\"EPSG\",\"8901\"]],UNIT[\"degree\", " +
"0.01745329251994328,AUTHORITY[\"EPSG\",\"9122\"]],AUTHORITY[\"EPSG\",\"4326\"]]";
CoordinateReferenceSystem crs = CRS.parseWKT(EPSG4326);
Point start = gf.createPoint(new Coordinate(longitude, latitude));
Point end = gf.createPoint(new Coordinate(longitudeDest, latitudeDest));
GeodeticCalculator gc = new GeodeticCalculator(crs);
gc.setStartingPosition(JTS.toDirectPosition(start.getCoordinate(), crs));
gc.setDestinationPosition(JTS.toDirectPosition(end.getCoordinate(), crs));
// Calculate distance between points
double distance = gc.getOrthodromicDistance();
int totalmeters = (int) distance;
int km = totalmeters / 1000;
int meters = totalmeters - (km * 1000);
float remaining_cm = (float) (distance - totalmeters) * 10000;
remaining_cm = Math.round(remaining_cm);
float cm = remaining_cm / 100;
System.out.println("Distance = " + km + "km " + meters + "m " + cm + "cm");
Coordinate[] coordinates = {start.getCoordinate(), end.getCoordinate()};
LineString line = gf.createLineString(coordinates);
SimpleFeatureTypeBuilder builder = new SimpleFeatureTypeBuilder();
builder.setName("TwoDistancesType");
builder.setCRS(DefaultGeographicCRS.WGS84);
//builder.add("start", Point.class);
//builder.add("end", Point.class);
builder.add("line", LineString.class);
// build the type
final SimpleFeatureType TYPE = builder.buildFeatureType();
SimpleFeatureBuilder featureBuilder = new SimpleFeatureBuilder(TYPE);
featureBuilder.add(line);
SimpleFeature feature = featureBuilder.buildFeature(null);
DefaultFeatureCollection featureCollection = new DefaultFeatureCollection("internal", TYPE);
featureCollection.add(feature);
// Create style for the line
//Style style = SLD.createSimpleStyle(TYPE, Color.red);
Style style = SLD.createLineStyle(Color.red, 2.0f);
Layer layer = new FeatureLayer(featureCollection, style);
// Create style for the file
Style shpStyle = SLD.createSimpleStyle(TYPE, Color.blue);
Layer shpLayer = new FeatureLayer(featureSource, shpStyle);
// Create a map content and add our shapefile to it
MapContent map = new MapContent();
map.setTitle("TEST");
map.addLayer(layer);
map.addLayer(shpLayer);
// Now display the map
JMapFrame.showMap(map);
}
我有两个问题:
1)如何显示线的方向?从起点到终点?
2)当你运行程序并看到地图时,你必须手动搜索线串(红线),然后缩放到地图才能找到它。有没有一种方法可以在搜索时自动缩放到线(坐标)地图出现?