MongoDB-JAVA-Driver 3.2版本常用代码全整理(4) - 地理空间索引

转载，原文连接：http://blog.csdn.net/autfish/article/details/51439742

MongoDB的3.x版本Java驱动相对2.x做了全新的设计，类库和使用方法上有很大区别。例如用Document替换BasicDBObject、通过Builders类构建Bson替代直接输入$命令等，本文整理了基于3.2版本的常用增删改查操作的使用方法。为了避免冗长的篇幅，分为增删改、查询、聚合、地理索引等几部分。

随着移动设备的普及，基于坐标和经纬度的位置查询变得越来越流行，例如查找离当前位置最近的N辆出租车。Mongodb专门针对这种查询建立了地理空间索引:2d和2dsphere索引。2d用于平面基于坐标的位置计算，2dsphere主要用于球体，比如地球，提供了基于弧度的位置计算。

 

import static com.mongodb.client.model.Indexes.geo2d;
import static com.mongodb.client.model.Indexes.geo2dsphere;

import java.text.ParseException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.bson.Document;

import com.mongodb.Block;
import com.mongodb.MongoClient;
import com.mongodb.client.FindIterable;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.model.Filters;
import com.mongodb.client.model.geojson.LineString;
import com.mongodb.client.model.geojson.Point;
import com.mongodb.client.model.geojson.Polygon;
import com.mongodb.client.model.geojson.Position;

public class GeospatialExamples {

    public static void main(String[] args) throws ParseException {
        MongoClient mongoClient = new MongoClient("localhost", 27017);
        MongoDatabase database = mongoClient.getDatabase("lesson");

        GeospatialExamples client = new GeospatialExamples(database);
        client.show();
        mongoClient.close();
    }

    private MongoDatabase database;
    public GeospatialExamples(MongoDatabase database) {
        this.database = database;
    }

    public void show() {
        MongoCollection<Document> mc = database.getCollection("people");
        mc.drop();

        Document doc1 = new Document("name", "tom").append("raid", Arrays.asList(10, 10)).append("gps", new Point(new Position(10, 10)));
        Document doc2 = new Document("name", "jone").append("raid", Arrays.asList(10.1, 10)).append("gps", new Point(new Position(10.1, 10)));
        Document doc3 = new Document("name", "john").append("raid", Arrays.asList(10, 10.1)).append("gps", new Point(new Position(10, 10.1)));
        Document doc4 = new Document("name", "jack").append("raid", Arrays.asList(9.9, 10)).append("gps", new Point(new Position(9.9, 10)));
        Document doc5 = new Document("name", "mary").append("raid", Arrays.asList(10, 9.9)).append("gps", new Point(new Position(10, 9.9)));
        Document doc6 = new Document("name", "abby").append("raid", Arrays.asList(10.2, 10)).append("gps", new Point(new Position(10.2, 10)));
        Document doc7 = new Document("name", "adam").append("raid", Arrays.asList(10.3, 10)).append("gps", new Point(new Position(10.3, 10)));
        Document doc8 = new Document("name", "barry").append("raid", Arrays.asList(10.4, 10)).append("gps", new Point(new Position(10.4, 10)));
        Document doc9 = new Document("name", "anne").append("raid", Arrays.asList(10.5, 10)).append("gps", new Point(new Position(10.5, 10)));
        mc.insertMany(Arrays.asList(doc1, doc2, doc3, doc4, doc5, doc6, doc7, doc8, doc9));

        mc.createIndex(geo2d("raid"));
        mc.createIndex(geo2dsphere("gps"));

        //$geoWithin 匹配任意几何图形内搜索
        FindIterable<Document> iterable = mc.find(Filters.geoWithin("raid", new Polygon(Arrays.asList(new Position(10.2, 10), new Position(10, 10.2), new Position(9.8, 10), new Position(10, 9.8), new Position(10.2, 10)))));
        printResult("Filters.geoWithin raid", iterable);

        //$geoWithinBox 在以左下角和右上角坐标构成方形内搜索
        iterable = mc.find(Filters.geoWithinBox("raid", 9.8, 9.8, 10.2, 10.2));
        printResult("Filters.geoWithinBox raid", iterable);

        //$geoWithinPolygon 在多边形内搜索
        List<Double> p1 = new ArrayList<>();
        List<Double> p2 = new ArrayList<>();
        List<Double> p3 = new ArrayList<>();
        p1.add(10d);
        p1.add(10d);
        p2.add(10.1);
        p2.add(10.16);
        p3.add(10.2);
        p3.add(10d);
        List<List<Double>> polygon = Arrays.asList(p1, p2, p3);
        iterable = mc.find(Filters.geoWithinPolygon("raid", polygon));
        printResult("Filters.geoWithinPolygon raid", iterable);

        p2.clear();
        p2.add(9.9);
        p2.add(10.16);
        p3.clear();
        p3.add(9.8);
        p3.add(10d);
        polygon = Arrays.asList(p1, p2, p3);
        iterable = mc.find(Filters.geoWithinPolygon("gps", polygon));
        printResult("Filters.geoWithinPolygon gps", iterable);

        //$geoWithinCenter 在指定圆心和半径的圆形内搜索
        iterable = mc.find(Filters.geoWithinCenter("raid", 10d, 10d, 0.25));
        printResult("Filters.geoWithinCenter raid", iterable);

        //$geoWithinCenterSphere 在球体(地球)上指定圆心和弧度搜索, 例如搜索以[10,10]为中心500米内的文档, 参数为...10d, 10d, 0.5/6371
        iterable = mc.find(Filters.geoWithinCenterSphere("gps", 10d, 10d, 11d/6371));
        printResult("Filters.geoWithinCenterSphere gps", iterable);

        //$geoIntersects
        iterable = mc.find(Filters.geoIntersects("gps", new LineString(Arrays.asList(new Position(10, 10.1), new Position(10.1, 10), new Position(10, 9.9)))));
        printResult("Filters.geoIntersects gps", iterable);

        //$near
        iterable = mc.find(Filters.near("gps", new Point(new Position(10, 10)), 20566d, 0d));
        printResult("Filters.near gps", iterable);

        //$nearSphere
        iterable = mc.find(Filters.nearSphere("gps", new Point(new Position(10, 10)), 20566d, 10d));
        printResult("Filters.nearSphere gps", iterable);
    }

    public void printResult(String doing, FindIterable<Document> iterable) {
        System.out.println(doing);
        iterable.forEach(new Block<Document>() {
            public void apply(final Document document) {
                System.out.println(document);
            }
        });
        System.out.println("------------------------------------------------------");
        System.out.println();
    }
}