最近有一個(gè)需求，需要去做大量空間數(shù)據(jù)的相交檢驗(yàn)督函，如果每一個(gè)圖形都去讀取出來(lái)與剩下的圖形去對(duì)比嘀粱，太耗費(fèi)時(shí)間和性能，一起做了很多不必要的相交辰狡。
為了稍微提升一些速度锋叨，借鑒了在空間數(shù)據(jù)處理分任務(wù)時(shí)的，片區(qū)劃分的方法宛篇，將與一個(gè)片區(qū)的取出來(lái)單獨(dú)處理娃磺，這樣會(huì)減少單次數(shù)據(jù)處理的量。 而且避免了很多相隔較遠(yuǎn)的數(shù)據(jù)的也需要去做相交比對(duì)的這種必要的操作叫倍。

下面就將我的做法分享出來(lái)

1.先貼pom.xml 文件

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>gis_data_fragment</artifactId>
    <version>1.0-SNAPSHOT</version>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>7</source>
                    <target>7</target>
                </configuration>
            </plugin>
        </plugins>
    </build>


    <dependencies>
        <dependency>
            <groupId>org.geotools</groupId>
            <artifactId>gt-main</artifactId>
            <version>28.2</version>
        </dependency>
        <dependency>
            <groupId>org.geotools</groupId>
            <artifactId>gt-opengis</artifactId>
            <version>28.2</version>
        </dependency>
        <dependency>
            <groupId>org.geotools</groupId>
            <artifactId>gt-metadata</artifactId>
            <version>28.2</version>
        </dependency>
        <dependency>
            <groupId>org.geotools</groupId>
            <artifactId>gt-shapefile</artifactId>
            <version>28.2</version>
        </dependency>
        <dependency>
            <groupId>org.geotools</groupId>
            <artifactId>gt-referencing</artifactId>
            <version>28.2</version>
        </dependency>
        <dependency>
            <groupId>org.geotools</groupId>
            <artifactId>gt-epsg-hsql</artifactId>
            <version>28.2</version>
        </dependency>
        <dependency>
            <groupId>org.geotools</groupId>
            <artifactId>gt-swing</artifactId>
            <version>28.2</version>
        </dependency>



        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.12.0</version>
        </dependency>
        <dependency>
            <groupId>org.locationtech.jts</groupId>
            <artifactId>jts-core</artifactId>
            <version>1.19.0</version>
        </dependency>

        <dependency>
            <groupId>si.uom</groupId>
            <artifactId>si-quantity</artifactId>
            <version>2.0.1</version>
        </dependency>
        <dependency>
            <groupId>si.uom</groupId>
            <artifactId>si-units</artifactId>
            <version>2.0.1</version>
        </dependency>
        <dependency>
            <groupId>si.uom</groupId>
            <artifactId>si-units-java8</artifactId>
            <version>0.7.1</version>
        </dependency>
        <dependency>
            <groupId>tech.units</groupId>
            <artifactId>indriya</artifactId>
            <version>2.0.4</version>
        </dependency>
        <dependency>
            <groupId>javax.measure</groupId>
            <artifactId>unit-api</artifactId>
            <version>2.1.3</version>
        </dependency>
        <dependency>
            <groupId>tech.uom.lib</groupId>
            <artifactId>uom-lib-common</artifactId>
            <version>2.1</version>
        </dependency>
        <dependency>
            <groupId>systems.uom</groupId>
            <artifactId>systems-common</artifactId>
            <version>2.0.2</version>
        </dependency>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13.2</version>
        </dependency>



    </dependencies>
    <repositories>
        <repository>
            <id>osgeo</id>
            <name>Open Source Geospatial Foundation Repository</name>
            <url>https://repo.osgeo.org/repository/release/</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
            <releases>
                <enabled>true</enabled>
            </releases>
        </repository>
    </repositories>
   
</project>

2. shp 文件讀取的方法 偷卧，同時(shí)獲取到數(shù)據(jù)的范圍，方便后面計(jì)算分片

引入的jar包

import org.geotools.data.DefaultTransaction;
import org.geotools.data.FeatureStore;
import org.geotools.data.Transaction;
import org.geotools.data.collection.ListFeatureCollection;
import org.geotools.data.shapefile.ShapefileDataStore;
import org.geotools.data.shapefile.ShapefileDataStoreFactory;
import org.geotools.data.simple.SimpleFeatureIterator;
import org.geotools.data.store.ContentFeatureCollection;
import org.geotools.data.store.ContentFeatureSource;
import org.geotools.feature.simple.SimpleFeatureBuilder;
import org.geotools.feature.simple.SimpleFeatureTypeBuilder;
import org.geotools.geometry.jts.JTSFactoryFinder;
import org.geotools.geometry.jts.ReferencedEnvelope;
import org.geotools.util.factory.FactoryFinder;
import org.locationtech.jts.geom.*;
import org.locationtech.jts.operation.union.UnaryUnionOp;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.feature.simple.SimpleFeatureType;

import javax.swing.*;
import java.io.File;
import java.io.IOException;
import java.io.Serializable;
import java.net.MalformedURLException;
import java.text.DecimalFormat;
import java.util.*;

// 地址就是這種  ./src/main/data/shp/pewg.shp段标，當(dāng)然也可以直接選一個(gè)硬盤(pán)上的地址
//傳入shp文件的地址涯冠，讀取數(shù)據(jù)，獲取數(shù)據(jù)范圍
    private void readSHP(String url) {
        //創(chuàng)建一個(gè)file對(duì)象
        File file = new File(url);
        ReferencedEnvelope bounds = new ReferencedEnvelope();
        try {
            ShapefileDataStore dataStore = new ShapefileDataStore(file.toURI().toURL());
            ContentFeatureSource featureSource = dataStore.getFeatureSource();
            ContentFeatureCollection features = featureSource.getFeatures();
            SimpleFeatureIterator featureIterator = features.features();

            //創(chuàng)建一個(gè)shp文件中的所有MultiPolygon的集合
            ArrayList<MultiPolygon> multiPolygons = new ArrayList<>();

           
            while (featureIterator.hasNext()) {
                SimpleFeature feature = featureIterator.next();
                multiPolygons.add((MultiPolygon) feature.getDefaultGeometry());
             }
            //1.獲取數(shù)據(jù)范圍
            bounds = featureSource.getBounds();
            //2.根據(jù)數(shù)據(jù)范圍逼庞，進(jìn)行數(shù)據(jù)分片，得到分片的分為
            Polygon[] polygons = partition(bounds, 15, 15);//對(duì)shp范圍進(jìn)行分區(qū)
            //3.將分片與數(shù)據(jù)相交瞻赶，得到每一小片相交的數(shù)據(jù)
            dataIntersectionDetection(polygons, multiPolygons);
            // polygonsAddToSHP(polygons); // 將切片圖形寫(xiě)入shp文件
            dataStore.dispose();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

3.根據(jù)數(shù)據(jù)范圍赛糟，計(jì)算分片的數(shù)量

/*
     *根據(jù)范圍數(shù)據(jù)，計(jì)算分片
     * bounds: 范圍
     * divisionsX：橫向分割數(shù)
     * divisionsY: 縱向分割數(shù)
     * */
    private Polygon[] partition(ReferencedEnvelope bounds, int divisionsX, int divisionsY) throws IOException {
        //最大最小的經(jīng)緯度點(diǎn)
        Coordinate bottomLeft = new Coordinate(
                keep9DecimalPlaces(bounds.getMinX()),
                keep9DecimalPlaces(bounds.getMinY())); // 左下角
        Coordinate topRight = new Coordinate(
                keep9DecimalPlaces(bounds.getMaxX()),
                keep9DecimalPlaces(bounds.getMaxY())); // 右上角
        double minX = bottomLeft.x;
        double minY = bottomLeft.y;
        double maxX = topRight.x;
        double maxY = topRight.y;

        //大矩形范圍
        Coordinate[] rectangleRadius = {
                bottomLeft,
                new Coordinate(bottomLeft.x, topRight.y),
                topRight,
                new Coordinate(topRight.x, bottomLeft.y),
                bottomLeft
        };

        // 將大矩形橫向和縱向劃分為10等分和5等分
        int numDivisionsX = divisionsX;
        int numDivisionsY = divisionsY;

        // 存放劃分好的小矩形的數(shù)組
        double[][][] dividedRectangles = new double[numDivisionsX][numDivisionsY][4];

        // 計(jì)算橫向和縱向的步長(zhǎng)
        double xStep = (maxX - minX) / numDivisionsX;
        double yStep = (maxY - minY) / numDivisionsY;

        // 劃分大矩形并將每個(gè)小矩形的四個(gè)頂點(diǎn)坐標(biāo)存放到數(shù)組中
        for (int i = 0; i < numDivisionsX; i++) {
            for (int j = 0; j < numDivisionsY; j++) {
                double x1 = (minX + i * xStep);
                double y1 = (minY + j * yStep);
                double x2 = (minX + (i + 1) * xStep);
                double y2 = (minY + (j + 1) * yStep);
                //dividedRectangles[i][j] = new double[]{x1, y1, x2, y2};
                dividedRectangles[i][j] = new double[]{
                        keep9DecimalPlaces(x1),
                        keep9DecimalPlaces(y1),
                        keep9DecimalPlaces(x2),
                        keep9DecimalPlaces(y2)
                };
            }
        }

        //將劃分的小矩形添加到MultiPolygon中
        GeometryFactory geometryFactory = JTSFactoryFinder.getGeometryFactory();
        Polygon[] polygons = new Polygon[numDivisionsX * numDivisionsY];
        int index = 0;
        for (double[][] row : dividedRectangles) {
            for (double[] rectangle : row) {
                Coordinate[] coordinate = {
                        new Coordinate(rectangle[0], rectangle[1]),
                        new Coordinate(rectangle[2], rectangle[1]),
                        new Coordinate(rectangle[2], rectangle[3]),
                        new Coordinate(rectangle[0], rectangle[3]),
                        new Coordinate(rectangle[0], rectangle[1]),
                };
                Polygon polygon = geometryFactory.createPolygon(coordinate);
                polygons[index] = polygon;
                ++index;
            }
        }

        return polygons;
    }

4.將分片數(shù)據(jù)與原始數(shù)據(jù)進(jìn)行相交砸逊，將每一片相交的元素?cái)?shù)據(jù)存到一個(gè)集合中

/*
     * 將分片數(shù)據(jù)和原始數(shù)據(jù)傳入方法
     * */
    private void dataIntersectionDetection(Polygon[] polygons, ArrayList<MultiPolygon> multiPolygons) throws IOException {
        // 將相交的數(shù)據(jù)存到一個(gè)大集合中
        ArrayList<ArrayList<MultiPolygon>> bigList = new ArrayList<>();

        for (int j = 0; j < polygons.length; j++) {
            //將每個(gè)相交的數(shù)據(jù)存到一個(gè)小集合
            ArrayList<MultiPolygon> smallList = new ArrayList<>();
            for (int m = 0; m < multiPolygons.size(); m++) {
                Polygon polygon = polygons[j];
                MultiPolygon multiPolygon = multiPolygons.get(m);
                boolean intersects = polygon.intersects(multiPolygon);// 是否相交
                if (intersects) {// 將相交的數(shù)據(jù)璧南，保存到一個(gè)集合中
                    smallList.add(multiPolygon);
                }
            }
            bigList.add(smallList);
        }

        /*// 將分片相交好的數(shù)據(jù)寫(xiě)入shp文件
        for (int i = 0; i < bigList.size(); i++) {
            if (bigList.get(i).isEmpty()) {// 為空的數(shù)據(jù)不寫(xiě)入
                continue;
            }
            multiPolygonsAddToSHP(bigList.get(i), i);
        }*/
    }

最后在分享幾個(gè) 將 圖形數(shù)據(jù) 寫(xiě)入shp文件的方法，方便進(jìn)行數(shù)據(jù)驗(yàn)證和查看

 //將多個(gè)Polygon添加到shp
    private void polygonsAddToSHP(Polygon[] polygons) throws IOException {
        // 創(chuàng)建Shapefile的DataStore
        File newFile = new File("src/main/data/shp/partition.shp");
        Map<String, Serializable> params = new HashMap<>();
        params.put("url", newFile.toURI().toURL());
        params.put("create spatial index", Boolean.TRUE);
        ShapefileDataStoreFactory dataStoreFactory = new ShapefileDataStoreFactory();
        ShapefileDataStore dataStore = (ShapefileDataStore) dataStoreFactory.createNewDataStore(params);

        // 定義FeatureType
        SimpleFeatureTypeBuilder typeBuilder = new SimpleFeatureTypeBuilder();
        typeBuilder.setName("Polygon");
        typeBuilder.setSRS("EPSG:4490");//設(shè)置坐標(biāo)系
        typeBuilder.add("the_geom", Polygon.class); // 將數(shù)據(jù)寫(xiě)入shp文件中 一定要是 the_geom
        typeBuilder.add("num", Integer.class);//添加一個(gè)num 用于取數(shù)據(jù)
        SimpleFeatureType featureType = typeBuilder.buildFeatureType();

        // 將FeatureType寫(xiě)入DataStore
        dataStore.createSchema(featureType);

        // 開(kāi)啟事務(wù)
        Transaction transaction = new DefaultTransaction("create");

        // 獲取FeatureStore
        String typeName = dataStore.getTypeNames()[0];
        FeatureStore<SimpleFeatureType, SimpleFeature> featureStore = (FeatureStore<SimpleFeatureType, SimpleFeature>) dataStore.getFeatureSource(typeName);

        // 創(chuàng)建FeatureList
        List<SimpleFeature> featureList = new LinkedList<>();
        for (int i = 0; i < polygons.length; i++) {
            SimpleFeatureBuilder featureBuilder = new SimpleFeatureBuilder(featureType);
            featureBuilder.add(polygons[i]);
            featureBuilder.add(i);
            SimpleFeature feature = featureBuilder.buildFeature(null);
            featureList.add(feature);
        }

        try {
            // 添加FeatureList到Shapefile
            ListFeatureCollection featureCollection = new ListFeatureCollection(featureType, featureList);
            featureStore.setTransaction(transaction);
            featureStore.addFeatures(featureCollection);
            transaction.commit();
        } catch (Exception e) {
            e.printStackTrace();
            transaction.rollback();
        } finally {
            transaction.close();
            dataStore.dispose();
        }

    }

    //將一個(gè)MultiPolygon添加到shp
    private void multiPolygonAddToSHP(MultiPolygon multiPolygon) throws IOException {
        // 創(chuàng)建Shapefile的DataStore
        File newFile = new File("src/main/data/shp/multiPolygon1.shp");
        Map<String, Serializable> params = new HashMap<>();
        params.put("url", newFile.toURI().toURL());
        params.put("create spatial index", Boolean.TRUE);
        ShapefileDataStoreFactory dataStoreFactory = new ShapefileDataStoreFactory();
        ShapefileDataStore dataStore = (ShapefileDataStore) dataStoreFactory.createNewDataStore(params);

        // 定義FeatureType
        SimpleFeatureTypeBuilder typeBuilder = new SimpleFeatureTypeBuilder();
        typeBuilder.setName("MultiPolygon");
        typeBuilder.setSRS("EPSG:4490");//設(shè)置坐標(biāo)系
        typeBuilder.add("the_geom", MultiPolygon.class); // 將數(shù)據(jù)寫(xiě)入shp文件中 一定要是 the_geom
        //typeBuilder.add("num", Integer.class);//添加一個(gè)num 用于取數(shù)據(jù)
        SimpleFeatureType featureType = typeBuilder.buildFeatureType();

        // 將FeatureType寫(xiě)入DataStore
        dataStore.createSchema(featureType);

        // 開(kāi)啟事務(wù)
        Transaction transaction = new DefaultTransaction("create");

        // 獲取FeatureStore
        String typeName = dataStore.getTypeNames()[0];
        FeatureStore<SimpleFeatureType, SimpleFeature> featureStore = (FeatureStore<SimpleFeatureType, SimpleFeature>) dataStore.getFeatureSource(typeName);

        // 創(chuàng)建Feature
        SimpleFeatureBuilder featureBuilder = new SimpleFeatureBuilder(featureType);
        featureBuilder.add(multiPolygon);
        SimpleFeature feature = featureBuilder.buildFeature(null);
        try {
            // 添加FeatureList到Shapefile
            ListFeatureCollection featureCollection = new ListFeatureCollection(featureType, feature);
            featureStore.setTransaction(transaction);
            featureStore.addFeatures(featureCollection);
            transaction.commit();
        } catch (Exception e) {
            e.printStackTrace();
            transaction.rollback();
        } finally {
            transaction.close();
            dataStore.dispose();
        }
    }

    // 將多個(gè)MultiPolygon添加到shp,生成多個(gè)shp
    private void multiPolygonsAddToSHP(ArrayList<MultiPolygon> multiPolygons, Integer num) throws IOException {
        // 創(chuàng)建Shapefile的DataStore
        File newFile = new File("src/main/data/shp/number/multiPolygons" + num + ".shp");
        Map<String, Serializable> params = new HashMap<>();
        params.put("url", newFile.toURI().toURL());
        params.put("create spatial index", Boolean.TRUE);
        ShapefileDataStoreFactory dataStoreFactory = new ShapefileDataStoreFactory();
        ShapefileDataStore dataStore = (ShapefileDataStore) dataStoreFactory.createNewDataStore(params);

        // 定義FeatureType
        SimpleFeatureTypeBuilder typeBuilder = new SimpleFeatureTypeBuilder();
        typeBuilder.setName("Polygon");
        typeBuilder.setSRS("EPSG:4490");//設(shè)置坐標(biāo)系
        typeBuilder.add("the_geom", MultiPolygon.class); // 將數(shù)據(jù)寫(xiě)入shp文件中 一定要是 the_geom
        SimpleFeatureType featureType = typeBuilder.buildFeatureType();

        // 將FeatureType寫(xiě)入DataStore
        dataStore.createSchema(featureType);

        // 開(kāi)啟事務(wù)
        Transaction transaction = new DefaultTransaction("create");

        // 獲取FeatureStore
        String typeName = dataStore.getTypeNames()[0];
        FeatureStore<SimpleFeatureType, SimpleFeature> featureStore = (FeatureStore<SimpleFeatureType, SimpleFeature>) dataStore.getFeatureSource(typeName);

        // 創(chuàng)建FeatureList
        List<SimpleFeature> featureList = new LinkedList<>();
        for (int i = 0; i < multiPolygons.size(); i++) {
            SimpleFeatureBuilder featureBuilder = new SimpleFeatureBuilder(featureType);
            featureBuilder.add(multiPolygons.get(i));
            SimpleFeature feature = featureBuilder.buildFeature(null);
            featureList.add(feature);
        }

        try {
            // 添加FeatureList到Shapefile
            ListFeatureCollection featureCollection = new ListFeatureCollection(featureType, featureList);
            featureStore.setTransaction(transaction);
            featureStore.addFeatures(featureCollection);
            transaction.commit();
        } catch (Exception e) {
            e.printStackTrace();
            transaction.rollback();
        } finally {
            transaction.close();
            dataStore.dispose();
        }
    }

    //將多個(gè)MultiPolygon合并為一個(gè)
    private MultiPolygon mergeMultiPolygons(List<MultiPolygon> multiPolygons) {
        // 合并的時(shí)間根據(jù)數(shù)據(jù)復(fù)雜程度师逸，時(shí)間可能會(huì)長(zhǎng)達(dá)幾分鐘司倚。
        UnaryUnionOp unaryUnionOp = new UnaryUnionOp(multiPolygons);
        return (MultiPolygon) unaryUnionOp.union();
    }

    // 保留9位小數(shù),經(jīng)緯度保留9未小數(shù)，精度約為0.0001米=0.1毫米
    private double keep9DecimalPlaces(double d) {
        DecimalFormat df = new DecimalFormat("#.#########");
        return Double.parseDouble(df.format(d));
    }