使用物化的地理空间半径搜索 [英] GeoSpatial Radius Search Using Objectify

问题描述

我正在使用 GeoModel 开发应用程序。我需要根据给定的经度和纬度在特定半径内执行搜索。我能够使用Objectify在数据存储中生成GeoCell，但无法在特定的半径范围内取回结果。

我在下面分享我的代码。

$ b

实体类$ b public class NewsFeed实现Serializable {
private static final long serialVersionUID = 1L;
@Id
@Index
私有长feedID;
@Index
private String topic;
@Index
私有字符串标题;
私有字符串描述;
@Index
private日期createDate;
私人字符串imageOrVideo;
private String imageUrl;
私人字符串blobKey;
@Latitude
私人双纬度;
@Longitude
私人双倍经度;
@Geocells
私人列表< String>细胞;

// getter and setters ...
}

自定义GeocellQueryEngine课程 来自此源

  public class ObjectifyGeocellQueryEngine实现GeocellQueryEngine {
 private String geocellsProperty; 
私人物品化; 
 public static final String DEFAULT_GEOCELLS_PROPERTY =cells; 
 
 public ObjectifyGeocellQueryEngine（Objectify ofy）{
 this（ofy，DEFAULT_GEOCELLS_PROPERTY）; 
} 
 
 public ObjectifyGeocellQueryEngine（Objectify ofy，String geocellsProperty）{
 this.ofy = ofy; 
 this.geocellsProperty = geocellsProperty; 
} 
 
 @Override 
 public< T>列表与LT; T> query（GeocellQuery baseQuery，List< String> geocells，Class< T> entityClass）{
 StringTokenizer st; 
 int tokenNo = 0; 
查询< T> query = ofy.query（entityClass）; 
 if（baseQuery！= null）{
 st = new StringTokenizer（baseQuery.getBaseQuery（），，）; $（st.hasMoreTokens（））{
 query.filter（st.nextToken（），baseQuery.getParameters（）。get（tokenNo ++））; 
 
 
返回query.filter（geocellsProperty +IN，geocells）.list（）; 
 
 
 
 
 
 $ b 
 在这里抓取数据 
  Point p = new Point（24.8993714，79.5839124）; 
 //生成GeoCells列表
 List< String> cells = GeocellManager.generateGeoCell（p）; 
列表< Object> params = new ArrayList< Object>（）; 
 params.add（电影）; 
 GeocellQuery baseQuery = new GeocellQuery（topic == topic，String topic，params）; 
 ObjectifyGeocellQueryEngine objectifyGeocellQueryEngine = new ObjectifyGeocellQueryEngine（ofy（），cells）; 
列出< NewsFeed> list = objectifyGeocellQueryEngine.query（baseQuery，cells，NewsFeed.class）; 
列出< NewsFeed> list2 = GeocellManager.proximitySearch（p，10，10000，NewsFeed.class，baseQuery，objectifyGeocellQueryEngine，GeocellManager.MAX_GEOCELL_RESOLUTION）; 
 System.out.println（list +：+ list2）; 
  
现在问题是我没有从这里得到任何结果。请问你们能否帮助我，因为我没有得到任何异常，只是得到空的名单。    

我已经完成了解决这种情况的方法我添加了一个并行JDO类来存储和检索地理空间结果。

I am developing an application using GeoModel. I need to perform search in a particular radius based on the given latitude and longitude. I am able to generate the GeoCells in the datastore using Objectify, but not able to get back the results in a particular radius.

I am sharing my code below.

Entity Class

@Entity
public class NewsFeed implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@Index
private Long feedID;
@Index
private String topic;
@Index
private String title;
private String description;
@Index
private Date createDate;
private String imageOrVideo;
private String imageUrl;
private String blobKey;
@Latitude
private Double latitude;
@Longitude
private Double longitude;
@Geocells
private List<String> cells;

    // getter and setters ...
}

Custom GeocellQueryEngine Class From This Source

public class ObjectifyGeocellQueryEngine implements GeocellQueryEngine {
private String geocellsProperty;
private Objectify ofy;
public static final String DEFAULT_GEOCELLS_PROPERTY = "cells";

public ObjectifyGeocellQueryEngine(Objectify ofy) {
    this(ofy, DEFAULT_GEOCELLS_PROPERTY);
}

public ObjectifyGeocellQueryEngine(Objectify ofy, String geocellsProperty) {
    this.ofy = ofy;
    this.geocellsProperty = geocellsProperty;
}

@Override
public <T> List<T> query(GeocellQuery baseQuery, List<String> geocells, Class<T> entityClass) {
    StringTokenizer st;
    int tokenNo = 0;
    Query<T> query = ofy.query(entityClass);
    if (baseQuery != null) {
        st = new StringTokenizer(baseQuery.getBaseQuery(), ",");
        while (st.hasMoreTokens()) {
            query.filter(st.nextToken(), baseQuery.getParameters().get(tokenNo++));
        }
    }
    return query.filter(geocellsProperty + " IN", geocells).list();
}
}

Fetching Data Here

    Point p = new Point(24.8993714, 79.5839124);
    // Generates the list of GeoCells
    List<String> cells = GeocellManager.generateGeoCell(p);
    List<Object> params = new ArrayList<Object>();
    params.add("Movies");
    GeocellQuery baseQuery = new GeocellQuery("topic == topic", "String topic",params);
    ObjectifyGeocellQueryEngine objectifyGeocellQueryEngine = new ObjectifyGeocellQueryEngine(ofy(), "cells");
    List<NewsFeed> list = objectifyGeocellQueryEngine.query(baseQuery, cells, NewsFeed.class);
    List<NewsFeed> list2 = GeocellManager.proximitySearch(p, 10, 10000,NewsFeed.class, baseQuery, objectifyGeocellQueryEngine, GeocellManager.MAX_GEOCELL_RESOLUTION);
    System.out.println(list+" : "+list2);

Now the problem is I am not getting any results out from here. Can you people please help me with this as I am not getting any exception, just getting the empty list.

解决方案

I have done a workaround for this situation I have added a parallel JDO Class to store and retrieve the geospatial results.

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