Question

我需要使用上面提到的坐标系将Shapefile导入并处理成使用WGS84坐标系的Java应用程序。

更具体地说，我读取shapefile并提取多边形，并将每个多边形存储到我的数据库中的对象。之后，我将不得不将空间点与这些多边形进行比较（检查点是否在其多边形内）。点和多边形在不同CRS中的事实似乎是我达到0次点击的原因。

虽然我认为这是无关紧要的，但以下是我使用GeoTools阅读shapefile的方法：

        InputStream stream = new FileInputStream("path/to/file");

        File tempDir = File.createTempFile("shapefile_temp", "");

        if (tempDir.exists())
            tempDir.delete();
        tempDir.mkdir();

        URL shpName = null;

        Files.unzip(stream, tempDir);

        for (File file : tempDir.listFiles())
            if (file.getName()
                    .endsWith(".shp"))
            {
                shpName = file.toURI()
                              .toURL();
                break;
            }

        if (shpName == null)
            throw new RuntimeException("No SHP found");

        Map<String, Object> map = new HashMap<String, Object>();

        map.put("url", shpName);
        DataStore dataStore = DataStoreFinder.getDataStore(map);

        try
        {
            String typeName = dataStore.getTypeNames()[0];

            FeatureSource<SimpleFeatureType, SimpleFeature> source = dataStore.getFeatureSource(typeName);

            FeatureIterator<SimpleFeature> iterator = source.getFeatures()
                                                            .features();

            while (iterator.hasNext())
            {

                Feature feature = iterator.next();

                System.out.println();
                System.out.println((int) feature.getProperty("COD_PRO")
                                                .getValue() + "\t" + feature.getProperty("NOME_PRO")
                                                                            .getValue());
                System.out.println(feature.getDefaultGeometryProperty()
                                          .getValue()); //This thing will be stored in a CQEngine and compared against a given point
            }

        }
        finally
        {
            tempDir.delete();
        }

    }
    finally
    {
        System.gc();
    }

以下代码更相关：如何检查点是否在形状内

    final GeometryFactory geoFactory = new GeometryFactory();
    com.vividsolutions.jts.geom.Point point = geoFactory.createPoint(new Coordinate(loc.getLongitude().doubleValue(), loc.getLatitude().doubleValue()));

                            loc.setContained(shape.getGeometry().covers(pointBing) || shape.getGeometry().contains(point));

如何将多边形从ED_1950转换为WGS84？或者，如何将WGS84点与ED_1950多边形进行比较？

Answer 1

首先，您需要从丹麦转变为WGS84：

CoordinateReferenceSystem worldCRS = CRS.decode("EPSG:4326");
CoordinateReferenceSystem ed_1950 = CRS.decode("EPSG:23032");
boolean lenient = true; // allow for some error due to different datums
MathTransform transform = CRS.findMathTransform(ed_1950, worldCRS, lenient);

然后，对于添加到数据库的每个Geometry，您需要对其进行转换：

Geometry geometry = (Geometry) feature.getDefaultGeometry();
Geometry geometry2 = JTS.transform(geometry, transform);

（我实际上没有编译过这段代码，但它应该有效 - 请参阅此tutorial了解更多详情。）

将ED_1950_UTM_Zone_32N（23032）转换为WGS84

1 个答案: