好久没用geotools去写东西了，因为近几年一直在接触所谓数字孪生和可视化相关项目，个人的重心也往前端可视化去倾斜，在后端的开发上到变得停滞下来。

这次用的是geotools 28.4版本，生成等值线的方法在

	<dependency>
		    <groupId>org.geotools</groupId>
		    <artifactId>gt-process-feature</artifactId>
		    <version>28.4</version>
		</dependency>

这是使用矢量点生成等值线，geotools中也提供了栅格影像生成等值线的方法，都是一个名字

ContourProcess，栅格的方法在：

	<dependency>
		    <groupId>org.geotools</groupId>
		    <artifactId>gt-process-raster</artifactId>
		    <version>${geotools.version}</version>
		</dependency>

中，本文仅结束矢量点生成等值线方法：

全部代码如下：

import java.io.File;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;

import org.geotools.data.DefaultTransaction;
import org.geotools.data.FileDataStore;
import org.geotools.data.FileDataStoreFinder;
import org.geotools.data.Transaction;
import org.geotools.data.shapefile.ShapefileDataStore;
import org.geotools.data.shapefile.ShapefileDataStoreFactory;
import org.geotools.data.simple.SimpleFeatureCollection;
import org.geotools.data.simple.SimpleFeatureSource;
import org.geotools.data.simple.SimpleFeatureStore;
import org.geotools.process.vector.ContourProcess;

public class MainP {

	public static void main(String[] args) {
        //点shp
		SimpleFeatureCollection sf = getGeometries("D:\\tmp\\inPoints.shp");
		ContourProcess cp = new ContourProcess();
		double[] levels = new double[]{};
		//如果进行线平滑，可能出现线相交情况！，“zfirst”为点shp图层中描述高度的属性字段名称，这里设置20米间隔进行等高线划分
		SimpleFeatureCollection outSF = cp.execute(sf, "zfirst", levels, 20.0, false, false, null);
		buildShpByFeatureCollection(outSF,"D:\\tmp\\contour.shp");
	}
	
	public static SimpleFeatureCollection getGeometries(String shpFilePath) {
		
		try {
			FileDataStore store = FileDataStoreFinder.getDataStore(new File(shpFilePath));
	        SimpleFeatureSource featureSource = store.getFeatureSource();
	        SimpleFeatureCollection simpleFeatureCollection = featureSource.getFeatures();
	        return simpleFeatureCollection;
		}catch(Exception ex) {
			System.out.println(ex.getMessage());
		}
		return null;
	}
	
	public static void buildShpByFeatureCollection(SimpleFeatureCollection collection, String outShpPath) {
        File outShpFile = new File(outShpPath);

        ShapefileDataStoreFactory dataStoreFactory = new ShapefileDataStoreFactory();

        try {
            Map<String, Serializable> params = new HashMap<>();
            params.put("url", outShpFile.toURI().toURL());
            params.put("create spatial index", Boolean.TRUE);

            ShapefileDataStore newDataStore = (ShapefileDataStore) dataStoreFactory.createNewDataStore(params);
            newDataStore.createSchema(collection.getSchema());

            Transaction transaction = new DefaultTransaction("create");

            String typeName = newDataStore.getTypeNames()[0];
            SimpleFeatureSource featureSource = newDataStore.getFeatureSource(typeName);

            if (featureSource instanceof SimpleFeatureStore) {
                SimpleFeatureStore featureStore = (SimpleFeatureStore) featureSource;
                featureStore.setTransaction(transaction);
                try {
                    featureStore.addFeatures(collection);
                    transaction.commit();
                } catch (Exception problem) {
                    problem.printStackTrace();
                    transaction.rollback();
                } finally {
                    transaction.close();
                }
                System.exit(0);
            } else {
                System.out.println(typeName + " does not support read/write access");
                System.exit(1);
            }
        } catch (Exception e) {
            throw new RuntimeException(e.getMessage(), e);
        }

    }
    

}