dem数据矢量化，并获取矢量化后每个点的海拔值存入矢量文件，Java代码

以下是使用Java进行DEM数据矢量化并获取每个点的海拔值存入矢量文件的示例代码：

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;

import org.gdal.gdal.Dataset;
import org.gdal.gdal.gdal;
import org.gdal.ogr.DataSource;
import org.gdal.ogr.Driver;
import org.gdal.ogr.Feature;
import org.gdal.ogr.FieldDefn;
import org.gdal.ogr.Geometry;
import org.gdal.ogr.Layer;
import org.gdal.ogr.ogr;

public class DEMtoVector {

    public static void main(String[] args) {

        // Load GDAL library
        gdal.AllRegister();

        // Input DEM file
        String demFile = "inputDEM.tif";

        // Output vector file
        String vectorFile = "outputVector.shp";

        // Open DEM file
        Dataset demDataset = gdal.Open(demFile, gdalconstConstants.GA_ReadOnly);

        // Get DEM metadata
        int width = demDataset.getRasterXSize();
        int height = demDataset.getRasterYSize();
        double[] geotransform = demDataset.GetGeoTransform();

        // Create output vector file
        Driver driver = ogr.GetDriverByName("ESRI Shapefile");
        File vectorFileObj = new File(vectorFile);
        if (vectorFileObj.exists()) {
            driver.DeleteDataSource(vectorFile);
        }
        DataSource vectorDataset = driver.CreateDataSource(vectorFile);

        // Create output layer
        Layer vectorLayer = vectorDataset.CreateLayer("elevation", null, ogr.wkbPoint, null);

        // Add elevation field to layer
        FieldDefn elevationField = new FieldDefn("elevation", ogr.OFTReal);
        vectorLayer.CreateField(elevationField);

        // Loop through DEM pixels and create point features for each pixel
        for (int y = 0; y < height; y++) {
            for (int x = 0; x < width; x++) {

                // Get elevation value for pixel
                double[] pixelValue = new double[1];
                demDataset.GetRasterBand(1).RasterIO(gdalconstConstants.GF_Read, x, y, 1, 1, pixelValue, 1, 1, gdalconstConstants.GDT_Float64, 0, 0);

                // Convert pixel coordinates to map coordinates
                double xMap = geotransform[0] + x * geotransform[1] + y * geotransform[2];
                double yMap = geotransform[3] + x * geotransform[4] + y * geotransform[5];

                // Create point geometry
                Geometry pointGeom = ogr.CreateGeometryFromWkt("POINT(" + xMap + " " + yMap + ")");

                // Create feature and set elevation field value
                Feature pointFeature = new Feature(vectorLayer.GetLayerDefn());
                pointFeature.SetGeometry(pointGeom);
                pointFeature.SetField("elevation", pixelValue[0]);

                // Add feature to layer
                vectorLayer.CreateFeature(pointFeature);
                pointFeature.delete();
                pointGeom.delete();
            }
        }

        // Clean up
        vectorDataset.delete();
        demDataset.delete();
        ogr.RegisterAll();
    }
}

在代码中，我们首先加载了GDAL库，然后指定了输入DEM文件和输出矢量文件的路径。接着，我们打开了DEM文件并获取了其元数据。然后，我们创建了输出矢量文件和输出图层，并添加了一个海拔字段到图层中。接下来，我们循环遍历DEM像素并为每个像素创建一个点特征。我们获取了像素的海拔值，并将像素坐标转换为地图坐标。然后，我们创建了一个点几何体并将其添加到特征中。最后，我们将特征添加到图层中。在代码的结尾，我们清理了GDAL资源并完成了DEM数据矢量化过程。