Geospark从Shapefile中加载RDD

我会带着你远行 2023-10-04 12:11 3阅读 0赞

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title: ‘（二）Geospark从Shapefile中加载RDD’  
date: 2021-04-29 19:09:48  
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> 从Shapefile中加载RDD
> 
> 我们从Shapefile中创建一个Spark的RDD,本次要导入的Shapefile是广州全市的公交站点.

## Geospark从Shapefile中加载RDD ##

#### 从Shapefile中加载RDD ####

1.  我们从Shapefile中创建一个Spark的RDD,本次要导入的Shapefile是广州全市的公交站点.

![img][]

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![img][img 1]

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1.  然后我们初始化一个SparkContext，并调用GeoSpark的ShapefileReader，将我们的Shape文件导入。

SparkConf conf = new SparkConf();
    conf.setAppName("GeoSpark02");
    conf.setMaster("local[*]");
    conf.set("spark.serializer", "org.apache.spark.serializer.KryoSerializer");
    conf.set("spark.kryo.registrator", "org.datasyslab.geospark.serde.GeoSparkKryoRegistrator");
    JavaSparkContext sc = new JavaSparkContext(conf);
    
    // Get SpatialRDD
    String shapeInputLocation = Learn02.class.getResource("/parks").toString();
    SpatialRDD rdd = ShapefileReader.readToGeometryRDD(sc, shapeInputLocation);

#### 查询 ####

##### 1. 使用Envelop查询 #####

//Envelop
    Envelope rangeQueryWindow = new Envelope(-123.1, -123.2, 49.2, 49.3);
    boolean considerBoundaryIntersection = false;// Only return gemeotries fully covered by the window
    boolean usingIndex = false;
    JavaRDD<Geometry> queryResult = RangeQuery.SpatialRangeQuery(rdd, rangeQueryWindow, considerBoundaryIntersection, usingIndex);
    System.out.println(String.format("查询结果总数为: %d",queryResult.count()));

查询结果总数为: 62

##### 2. 使用Geomtery查询 #####

GeoSpark提供了GeomtryFactory来构造Polygon、Line、Point等Geometry。

// Geometry
    GeometryFactory geometryFactory = new GeometryFactory();
    Coordinate[] coordinates = new Coordinate[5];
    coordinates[0] = new Coordinate(-123.1,49.2);
    coordinates[1] = new Coordinate(-123.1,49.3);
    coordinates[2] = new Coordinate(-123.2,49.3);
    coordinates[3] = new Coordinate(-123.2,29.2);
    coordinates[4] = coordinates[0]; // The last coordinate is the same as the first coordinate in order to compose a closed ring
    Polygon polygonObject = geometryFactory.createPolygon(coordinates);
    queryResult = RangeQuery.SpatialRangeQuery(rdd, polygonObject, considerBoundaryIntersection, usingIndex);
    System.out.println(String.format("查询结果总数为: %d",queryResult.count()));

查询结果总数为: 62

##### 3. 输出查询结果 #####

// 遍历查询结果
    queryResult.foreach(new VoidFunction<Geometry>() {
        
        @Override
        public void call(Geometry geometry) throws Exception {
        
            System.out.println(geometry);
        }
    });

POLYGON ((-123.15566057081632 49.26206733490204, -123.15564728017853 49.26241791476514, -123.15548939905344 49.262415429329856, -123.15550257747702 49.26206484963618, -123.15566057081632 49.26206733490204))  1   -9999       Kitsilano           N       
    POLYGON ((-123.15760176703519 49.261936547646954, -123.15718706338478 49.2619299178749, -123.15719832396375 49.26162160945501, -123.15761313807661 49.26162814910161, -123.15760218456263 49.26192530535148, -123.15760176703519 49.261936547646954))   2   208 Rosemary Brown Park Kitsilano   W 11th Avenue   Vine Street N   N   N
    .................................
    POLYGON ((-123.12325003271694 49.290529597005786, -123.12325184999034 
    POLYGON ((-123.11921795166444 49.288179012132034, -123.11889234917355 49.28806261407178, -123.11905901714364 49.28781953241384, -123.11954592548769 49.28796238352621, -123.11921795166444 49.288179012132034)) 80  27  Portal Park Downtown    W Hastings Street   Thurlow Street  N   N   N

参考链接：https://www.jianshu.com/p/4b9e875227aa

[img]: https://img-blog.csdnimg.cn/img_convert/780aca1619b25c930ad042b63ac7889f.png
[img 1]: https://img-blog.csdnimg.cn/img_convert/90252a5138eaa727645a8b8567d1c4b7.png