如何使用 GeoTools 创建具有纬度、经度和半径的圆？

现在我有：

Polygon circle = geometryBuilder.circle(
myLong,
myLat, 
radiusInMeters, 10);

它创建（纬度=28.456306，长=-16.292034，半径=500）一个具有巨大纬度和经度的无意义多边形，例如：

POLYGON ((483.678055 28.482505000000003, 388.1865521874737 -265.4101211462366, 138.1865521874737 -447.04575314757676, -170.8304421874737 -447.0457531475768, -420.8304421874737 -265.41012114623663, -516.321945 28.482504999999943, -420.83044218747375 322.3751311462365, -170.8304421874738 504.01076314757677, 138.18655218747358 504.0107631475768, 388.18655218747364 322.3751311462367, 483.678055 28.482505000000003))

我期望在我提供的中心点附近有十对带有经纬度的坐标。

任何帮助都会更有帮助。提前致谢！

EDIT

除了@iant的答案之外，我还必须创建一个Point as a Feature

//build the type
SimpleFeatureType TYPE = null;
try {
    TYPE = DataUtilities.createType("", "Location", "locations:Point:srid=4326," + "id:Integer" // a
            // number
            // attribute
            );
} catch (Exception e1) {
    // TODO Auto-generated catch block
    e1.printStackTrace();
}

SimpleFeatureBuilder featureBuilder = new SimpleFeatureBuilder(TYPE);
GeometryFactory geometryFactory = JTSFactoryFinder.getGeometryFactory();
com.vividsolutions.jts.geom.Point point = geometryFactory.createPoint(
        new Coordinate(
                currentDevicePosition.getLongitude(), 
                currentDevicePosition.getLatitude()
                )
        );
featureBuilder.add(point);
SimpleFeature feature = featureBuilder.buildFeature( "fid.1" ); // build the 1st feature

正如iant的要点中所解释的：https://gitlab.com/snippets/17558 https://gitlab.com/snippets/17558和这里：http://docs.geotools.org/ http://docs.geotools.org/，哦，而且我还缺少一个依赖项，如此处解释的java中的Schema异常 https://stackoverflow.com/questions/19356113/schemaexception-in-java

对此有两种解决方案：

1. 将半径（米）转换为度并将问题视为平面问题

2. 将纬度/经度点转换为米，计算局部平面投影中的圆，然后重新投影回纬度/经度。

对于 1 ，你可以做类似的事情，这对于赤道附近的小半径来说是很好的：

GeodeticCalculator calc = new  GeodeticCalculator(DefaultGeographicCRS.WGS84);
  calc.setStartingGeographicPoint(point.getX(), point.getY());
  calc.setDirection(0.0, 10000);
  Point2D p2 = calc.getDestinationGeographicPoint();
  calc.setDirection(90.0, 10000);
  Point2D p3 = calc.getDestinationGeographicPoint();

  double dy = p2.getY() - point.getY();
  double dx = p3.getX() - point.getX();
  double distance = (dy + dx) / 2.0;
  Polygon p1 = (Polygon) point.buffer(distance);

我将展示第二个的一些代码，因为它更通用（即它工作得更好并且半径范围更大）。

首先需要找到本地投影，GeoTools提供了“伪”投影AUTO42001,x,y这是以 X,Y 为中心的 UTM 投影：

public SimpleFeature bufferFeature(SimpleFeature feature, Measure<Double, Length> distance) {
    // extract the geometry
    GeometryAttribute gProp = feature.getDefaultGeometryProperty();
    CoordinateReferenceSystem origCRS = gProp.getDescriptor().getCoordinateReferenceSystem();

    Geometry geom = (Geometry) feature.getDefaultGeometry();
    Geometry pGeom = geom;
    MathTransform toTransform, fromTransform = null;
    // reproject the geometry to a local projection
    if (!(origCRS instanceof ProjectedCRS)) {

      double x = geom.getCoordinate().x;
      double y = geom.getCoordinate().y;

      String code = "AUTO:42001," + x + "," + y;
      // System.out.println(code);
      CoordinateReferenceSystem auto;
      try {
        auto = CRS.decode(code);
        toTransform = CRS.findMathTransform(DefaultGeographicCRS.WGS84, auto);
        fromTransform = CRS.findMathTransform(auto, DefaultGeographicCRS.WGS84);
        pGeom = JTS.transform(geom, toTransform);

      } catch (MismatchedDimensionException | TransformException | FactoryException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
      }

    }

So now pGeom是以米为单位的点。缓冲现在很容易

  Geometry out = bufferFeature(pGeom, distance.doubleValue(SI.METER)); 

然后我们使用之前查找的反向变换投影回 WGS84（纬度/经度）：

  retGeom = JTS.transform(out, fromTransform); 

然后，需要稍微修改一下要素类型，以反映我们返回的是多边形而不是点的事实。完整代码在此gist https://gitlab.com/snippets/17558.

当我运行它时，我得到以下输出：

POINT (10.840378413128576 3.4152050343701745)
POLYGON ((10.84937634426605 3.4151876838951822, 10.849200076653755 3.413423962919184, 10.84868480171117 3.4117286878605766, 10.847850322146979 3.4101670058279794, 10.846728706726902 3.4087989300555464, 10.845363057862208 3.407677033830687, 10.843805855306746 3.406844430298736, 10.84211693959797 3.406333115754347, 10.840361212705258 3.4061627400701946, 10.838606144204721 3.4063398515107184, 10.836919178768184 3.4068576449605277, 10.835365144548726 3.4076962232621035, 10.834003762019957 3.408823361646906, 10.832887348980522 3.410195745914279, 10.832058809914859 3.411760636805914, 10.831549986992338 3.4134578966399034, 10.831380436105858 3.4152223003379722, 10.831556675029052 3.416986042039048, 10.832071932633442 3.4186813409639054, 10.832906408849936 3.4202430463705085, 10.834028035422469 3.4216111414662183, 10.835393708241908 3.422733050021835, 10.836950943907517 3.4235656570147763, 10.838639896841123 3.424076965623486, 10.840395659406198 3.4242473268789406, 10.842150756595839 3.4240701947133396, 10.843837739370569 3.4235523773972796, 10.845391776937724 3.4227137757216988, 10.846753148314034 3.4215866180136185, 10.847869537398722 3.4202142214154887, 10.848698043354238 3.4186493270628633, 10.849206829051935 3.4169520731645546, 10.84937634426605 3.4151876838951822))