ElasticSearch

ES地理范围查询第一讲:Java操作地理位置信息(geo_poi

2018-03-07  本文已影响0人  追杀丘比特
- 简要介绍

我们知道es支持的数据类型是多种多样的,除了我们常见的几种基本数据类型,它也支持记录位置信息的的数据类型。在es中,记录地理位置信息的数据类型有两种,分别为geo_shap和geo_point,下面我针对geo_point类型简要介绍一下
geo_point支持多种数据传入方式:

  1. 字符串
    位置:lat + "," + lon
  2. 数组
    位置: {"lat": ...,"lon": ...}
  3. 对象
    位置: [lon, lat]

注意:可能所有人都至少踩过一次这个坑====地理坐标点用字符串形式表示时是纬度在前,经度在后("latitude,longitude"),而数组形式表示时刚好相反,是经度在前,纬度在后([longitude,latitude])。其实,在 Elasticesearch 内部,不管字符串形式还是数组形式,都是纬度在前,经度在后。不过早期为了适配GeoJSON 的格式规范,调整了数组形式的表示方式。这点官网有说明。

针对geo_point类型一般有如下几种查询需求

  1. distance query
    查找距离中心点范围内的点
  2. distance range query
    查询位于中心点指定range内的点,这个api在新版本的es中去掉了,因此这里不做过多解释
  3. bounding query
    查找指定点组成的矩形范围内的点
  4. polygon query
    查找多个点组成的一个多边形中的点

针对不同的查询Java构造的SearchSourceBuilder factory如下:

public class QueryFactory {
  
    /**
     * 针对geo_point类型的查找,查询符合多边形内的数据
     * @param field
     * @param points
     * @return
     * @throws Exception
     */
    public SearchSourceBuilder builtPolygonQuery(String field, List<GeoPoint> points) throws Exception {
        if (points == null || points.size() <= 0) {
            throw new Exception("bad args of geo points");
        }
        SearchSourceBuilder srb = new SearchSourceBuilder();
        GeoPolygonQueryBuilder qb = QueryBuilders.geoPolygonQuery(field, points);
        srb.query(qb);
        return srb;
    }


    /**
     * 针对geo_point类型
     * 获取在指定矩形框内的数据
     * @param field 字段
     * @param point1 矩形左上边界
     * @param point2 矩形右下边界
     * @return
     * @throws Exception
     */
    public SearchSourceBuilder builtBoundingBoxQuery(String field, GeoPoint point1,GeoPoint point2) throws Exception {
        if (point1 == null || point2 == null) {
            throw new Exception("bad args of geo points");
        }
        SearchSourceBuilder srb = new SearchSourceBuilder();
        GeoBoundingBoxQueryBuilder qb = QueryBuilders.geoBoundingBoxQuery(field)
                .setCorners(point2,point1);
        srb.query(qb);
        return srb;
    }

    /**
     * 针对geo_point类型
     * 查找在给定的中心点确定范围内的数据
     * @param field
     * @param distance
     * @param point
     * @return
     * @throws Exception
     */
    public SearchSourceBuilder builtDistanceQuery( String field,String distance, GeoPoint point) throws Exception {
        if (point == null) {
            throw new Exception("bad args of geo points");
        }
        SearchSourceBuilder srb = new SearchSourceBuilder();
        QueryBuilder qb = QueryBuilders.geoDistanceQuery(field)
                .point(point)
                .distance(distance, DistanceUnit.KILOMETERS);
        srb.query(qb);
        GeoDistanceSortBuilder sort = SortBuilders.geoDistanceSort(field,point)
                .order(SortOrder.ASC)
                .unit(DistanceUnit.KILOMETERS);
        srb.sort(sort);
        return srb;
    }
}

service如下:

/**
     * 查找位于多边形中的位置
     * @param index 索引
     * @param type  类型
     * @param field 索引字段
     * @param points  构成多边形的点
     */
    public List<Map<String, Object>> searchGeoPolygon(String index, String type, String field, List<GeoPoint> points) throws Exception {
        SearchSourceBuilder builder = factory.builtPolygonQuery(field, points);
        return search(index, type, builder);
    }

    /**
     * 查询矩形范围内的数据
     * @param index index
     * @param type  type
     * @param field 索引字段
     * @param bottom_right 右上坐标
     * @param top_left 左下坐标
     */
    public List<Map<String, Object>> searchGeoBoundingBox(String index, String type, String field, GeoPoint bottom_right,GeoPoint top_left) throws Exception {
        SearchSourceBuilder builder = factory.builtBoundingBoxQuery(field,bottom_right,top_left);
        return search(index,type, builder);
    }

    /**
     * 查询距离中心点指定的范围内的位置
     * @param index index
     * @param type type
     * @param field 索引字段
     * @param distance 距离
     * @param point 中心点
     * @return
     * @throws Exception
     */
    public List<Map<String, Object>> searchGeoDistance(String index, String type, String field,String distance, GeoPoint point) throws Exception {
        SearchSourceBuilder builder = factory.builtDistanceQuery(field,distance,point);
        return search(index, type, builder);
    }

    /**
     * 执行查询
     * @param index 索引
     * @param type type
     * @param builder 查询语句
     * @return List<Map>
     */
    private List<Map<String, Object>> search(String index, String type, SearchSourceBuilder builder) {
        try {
            client = oldclient.setupTransportClient();
            List<Map<String, Object>> list = new ArrayList<>();
            SearchRequestBuilder srb = client.prepareSearch(index);
            if (type != null && type.length() != 0){
                srb.setTypes(type);
            }
            srb.setSource(builder);
            SearchResponse searchResponse = srb.execute().actionGet();
            SearchHits hits = searchResponse.getHits();
            long time = searchResponse.getTookInMillis()/1000;
            logger.info("query result size:"+hits.totalHits+",spend time:"+time+"s");
            for (SearchHit hit : hits) {
                Map<String, Object> map = hit.getSource();
                //获取distance数据时,获取距离具体值
                if (hit.getSortValues().length != 0){
                    BigDecimal geoDis = new BigDecimal((Double) hit.getSortValues()[0]);
                    map.put("距离",geoDis.setScale(4, BigDecimal.ROUND_HALF_DOWN)+"km");
                }
                list.add(map);
                logger.info("hits:" + map);
            }
            return list;
        } catch (Exception e) {
            logger.error("error!", e);
        }
        return null;
    }

controller层代码如下:

@RestController
@RequestMapping("/geo")
public class GeoDataRestController {
    private Logger logger = Logger.getLogger(GeoDataRestController.class);

    @Autowired
    private EsSearchService service;


    @RequestMapping(value = "/distance",method = RequestMethod.POST)
    public List<Map<String,Object>> searchGeoWithDistance(@RequestBody RequestBean bean,
                                                          @Param("distance") String distance){
         Map<String,GeoPoint> map = bean.getPoints();
         GeoPoint point = map.get("point");
        if (distance == null || point == null){
            logger.error("request param error!");
            return null;
        }
        List<Map<String,Object>> result= null;
        try {
            result = service.searchGeoDistance(bean.getIndex(),bean.getType(),bean.getField(),distance,point);
        }catch (Exception e){
            logger.error("query error!",e);
        }
        return result;
    }

    @RequestMapping(value = "/bounding",method = RequestMethod.POST)
    public List<Map<String,Object>> searchGeoWithBoundingBox(@RequestBody RequestBean bean){
        Map<String,GeoPoint> map = bean.getPoints();
        GeoPoint bottom_point = map.get("bottom_right");
        GeoPoint top_left = map.get("top_left");
        if (bottom_point == null || top_left == null){
            logger.error("request param error!");
            return null;
        }
        List<Map<String,Object>> result= null;
        try {
            result = service.searchGeoBoundingBox(bean.getIndex(),bean.getType(),bean.getField(),bottom_point,top_left);
        }catch (Exception e){
            logger.error("query error!",e);
        }
        return result;
    }

    @RequestMapping(value = "/coordinate",method = RequestMethod.POST)
    public List<Map<String,Object>> searchGeoWithCoordinate(@Param("index") String index,
                                                            @Param("type") String type,
                                                            @Param("field") String field,
                                                            @RequestBody List<GeoPoint> points){
        logger.info("data:"+points);
        List<Map<String,Object>> result= null;
        try {
            result = service.searchGeoPolygon(index,type,field,points);
        }catch (Exception e){
            logger.error("query error!",e);
        }
        return result;
    }
}
[1].如何使用

我们在使用geo_point类型之前,首先应该在创建index时通过mapping显式指定该字段为geo_point类型,如下:

{
  "restraunt": {
    "mappings": {
      "info": {
        "properties": {
          "位置": {
            "type": "geo_point"
          },
          "房间号": {
            "type": "text",
            "analyzer": "ik_max_word",
            "search_analyzer": "ik_smart"
          },
          "描述信息": {
            "type": "text",
            "analyzer": "ik_max_word",
            "search_analyzer": "ik_smart"
          },
          "电话号码": {
            "type": "text"
          }
        }
      }
    }
  }
}

以上我们新建了一个名字为restraunt的index,在它的mapping文件中显式的指定了“位置”字段的type为“geo_point”类型

[2]准备一些数据

在kibana上我们准备的数据如下:

1.{
  "_index": "restraunt",
  "_type": "info",
  "_id": "1-0-0-6",
  "_version": 1,
  "_score": 1,
  "_source": {
    "房间号": "1-0-0-6",
    "描述信息": "李三吱的房子,依法查封",
    "位置": "32.4428148,105.7701854",
    "电话号码": "18212345693"
  }
}
2.{
  "_index": "restraunt",
  "_type": "info",
  "_id": "1-0-0-5",
  "_version": 1,
  "_score": 1,
  "_source": {
    "房间号": "1-0-0-5",
    "描述信息": "李三吱的房子,依法查封",
    "位置": "31.4673768,104.582626",
    "电话号码": "18212345693"
  }
}
3.{
  "_index": "restraunt",
  "_type": "info",
  "_id": "1-0-0-1",
  "_version": 1,
  "_score": 1,
  "_source": {
    "房间号": "1-0-0-1",
    "描述信息": "李三吱的房子,依法查封",
    "位置": "31.1120885,104.2664256",
    "电话号码": "18212345693"
  }
}
4.{
  "_index": "restraunt",
  "_type": "info",
  "_id": "1-0-0-2",
  "_version": 1,
  "_score": 1,
  "_source": {
    "房间号": "1-0-0-2",
    "描述信息": "李三吱的房子,依法查封",
    "位置": "30.6587488,103.9354626",
    "电话号码": "18212345693"
  }
}
5.{
  "_index": "restraunt",
  "_type": "info",
  "_id": "1-0-0-3",
  "_version": 1,
  "_score": 1,
  "_source": {
    "房间号": "1-0-0-3",
    "描述信息": "李三吱的房子,依法查封",
    "位置": "30.1260332,104.6028895",
    "电话号码": "18212345693"
  }
}
6.{
  "_index": "restraunt",
  "_type": "info",
  "_id": "1-0-0-4",
  "_version": 1,
  "_score": 1,
  "_source": {
    "房间号": "1-0-0-4",
    "描述信息": "李三吱的房子,依法查封",
    "位置": "30.5128458,105.5106333",
    "电话号码": "18212345693"
  }
}
7.{
  "_index": "restraunt",
  "_type": "info",
  "_id": "1-0-0-7",
  "_version": 1,
  "_score": 1,
  "_source": {
    "房间号": "1-0-0-7",
    "描述信息": "李三吱的房子,依法查封",
    "位置": "30.0013669,102.9725838",
    "电话号码": "18212345693"
  }
}

以上我们准备了7条数据,接下来我们需要执行查询,看看我们的接口是否符合我们需求。

[3]查询
post : http://localhost:8081/geo/distance?distance=300 //查询距离points 300km之间的点
body:
  {
    "index": "restraunt",
    "field": "位置",
    "points": {
        "point": {
            "lat": 32.4428148,
            "lon": 105.7701854
        }
    }
} 
response result:
[
    {
        "房间号": "1-0-0-6",
        "描述信息": "李三吱的房子,依法查封",
        "位置": "32.4428148,105.7701854",
        "电话号码": "18212345693",
        "距离": "0.0000km"
    },
    {
        "房间号": "1-0-0-5",
        "描述信息": "李三吱的房子,依法查封",
        "位置": "31.4673768,104.582626",
        "电话号码": "18212345693",
        "距离": "155.9380km"
    },
    {
        "房间号": "1-0-0-1",
        "描述信息": "李三吱的房子,依法查封",
        "位置": "31.1120885,104.2664256",
        "电话号码": "18212345693",
        "距离": "205.1788km"
    },
    {
        "房间号": "1-0-0-4",
        "描述信息": "李三吱的房子,依法查封",
        "位置": "30.5128458,105.5106333",
        "电话号码": "18212345693",
        "距离": "216.0097km"
    },
    {
        "房间号": "1-0-0-2",
        "描述信息": "李三吱的房子,依法查封",
        "位置": "30.6587488,103.9354626",
        "电话号码": "18212345693",
        "距离": "263.7685km"
    },
    {
        "房间号": "1-0-0-3",
        "描述信息": "李三吱的房子,依法查封",
        "位置": "30.1260332,104.6028895",
        "电话号码": "18212345693",
        "距离": "280.4747km"
    }
]

其他两种查询同上。

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