Elasticsearch的相关文章：

Elasticsearch读书笔记(一)

Docker版Elasticsearch的安装配置

基于SpringBoot、Elasticsearch酒店搜索

Elasticsearch根据日期价格范围搜索酒店

第四篇写了如何根据日期、价格范围来搜索酒店，用到了nested的相关知识点。在实际应用中，还有个排序的功能，例如：

整个需求变成了：

搜索符合关键词、日期范围、价格范围​的酒店列表，且按照其最低价格​排序。

前文中​搜索的DSL语句为：

{  "query": {    "bool": {      "must": [{          "match": {            "searchKeywords": "北京"          }        },        {          "nested": {            "path": "minPriceCalendar",            "query": {              "range": {                "minPriceCalendar.date": {                  "gte": "2020-11-11",                  "lte": "2020-11-15"                }              }            }          }        },        {          "nested": {            "path": "minPriceCalendar",            "query": {              "range": {                "minPriceCalendar.minPrice": {                  "gte": 450,                  "lte": 700                }              }            }          }        }      ]    }  }}

​结果中，只要符合上述条件的酒店都会搜索出来：

1、在北京。

2、11~15号有房。

3、价格在450~700。

按照道理只需要对搜出来的结果中的价格日历minPriceCalendar做一下指标聚合，再排序就行了​，如下：​

{  "query": {    "bool": {      "must": [        {          "match": {            "searchKeywords": "北京"          }        },        {          "nested": {            "path": "minPriceCalendar",            "query": {              "range": {                "minPriceCalendar.date": {                  "gte": "2020-11-14",                  "lte": "2020-11-15"                }              }            }          }        },        {          "nested": {            "path": "minPriceCalendar",            "query": {              "range": {                "minPriceCalendar.minPrice": {                  "gte": 200,                  "lte": 700                }              }            }          }        }      ]    }  },  "sort": [    {      "minPriceCalendar.minPrice": {        "mode": "min",        "order": "asc",        "nested": {          "path": "minPriceCalendar"        }      }    }  ]}

但是这里的问题就在于，Elasticsearch会把所有符合要求的文档原封不动地搜索出来。

看结果：

{  "took" : 1,  "timed_out" : false,  "_shards" : {    "total" : 1,    "successful" : 1,    "skipped" : 0,    "failed" : 0  },  "hits" : {    "total" : {      "value" : 3,      "relation" : "eq"    },    "max_score" : null,    "hits" : [      {        "_index" : "idx2",        "_type" : "_doc",        "_id" : "2",        "_score" : null,        "_source" : {          "hotelId" : 2,          "searchKeywords" : "北京 王府井",          "minPriceCalendar" : [            {              "date" : "2020-11-11",              "minPrice" : 110            },            {              "date" : "2020-11-12",              "minPrice" : 220            },            {              "date" : "2020-11-13",              "minPrice" : 330            },            {              "date" : "2020-11-14",              "minPrice" : 440            }          ]        },        "sort" : [          110        ]      },      {        "_index" : "idx2",        "_type" : "_doc",        "_id" : "5",        "_score" : null,        "_source" : {          "hotelId" : 5,          "searchKeywords" : "北京 金融街",          "minPriceCalendar" : [            {              "date" : "2020-11-11",              "minPrice" : 111            },            {              "date" : "2020-11-12",              "minPrice" : 222            },            {              "date" : "2020-11-13",              "minPrice" : 333            },            {              "date" : "2020-11-14",              "minPrice" : 444            }          ]        },        "sort" : [          111        ]      },      {        "_index" : "idx2",        "_type" : "_doc",        "_id" : "4",        "_score" : null,        "_source" : {          "hotelId" : 4,          "searchKeywords" : "北京 西单",          "minPriceCalendar" : [            {              "date" : "2020-11-15",              "minPrice" : 555            }          ]        },        "sort" : [          555        ]      }    ]  }}

注意看sort的值。

假设：

A酒店价格日历​：1号110，2号200，3号300​；

B酒店价格日历​：2号120，3号310​。

搜索日期2~3号，价格100~400的酒店，按最低价格排序。

AB酒店都命中，排序的时候，B酒店2~3号的最低价是120，大于A酒店的最低价200，排在前面。

但因为二者的价格日历都带出来了，所以A酒店最低价格是1号的110，B酒店最低价格是2号的​120，反而把A排在前面​。

所以我们还要对排序​再做一下过滤：

{  "query": {    "bool": {      "must": [        {          "match": {            "searchKeywords": "北京"          }        },        {          "nested": {            "path": "minPriceCalendar",            "query": {              "range": {                "minPriceCalendar.date": {                  "gte": "2020-11-14",                  "lte": "2020-11-15"                }              }            }          }        },        {          "nested": {            "path": "minPriceCalendar",            "query": {              "range": {                "minPriceCalendar.minPrice": {                  "gte": 200,                  "lte": 700                }              }            }          }        }      ]    }  },  "sort": [    {      "minPriceCalendar.minPrice": {        "mode": "min",        "order": "asc",        "nested": {          "path": "minPriceCalendar",          "filter": {            "bool": {              "must": [                {                  "range": {                    "minPriceCalendar.date": {                      "gte": "2020-11-14",                      "lte": "2020-11-15"                    }                  }                },                {                  "range": {                    "minPriceCalendar.minPrice": {                      "gte": 200,                      "lte": 700                    }                  }                }              ]            }          }        }      }    }  ]}

搜索结果如下：

{  "took" : 1,  "timed_out" : false,  "_shards" : {    "total" : 1,    "successful" : 1,    "skipped" : 0,    "failed" : 0  },  "hits" : {    "total" : {      "value" : 3,      "relation" : "eq"    },    "max_score" : null,    "hits" : [      {        "_index" : "idx2",        "_type" : "_doc",        "_id" : "2",        "_score" : null,        "_source" : {          "hotelId" : 2,          "searchKeywords" : "北京 王府井",          "minPriceCalendar" : [            {              "date" : "2020-11-11",              "minPrice" : 110            },            {              "date" : "2020-11-12",              "minPrice" : 220            },            {              "date" : "2020-11-13",              "minPrice" : 330            },            {              "date" : "2020-11-14",              "minPrice" : 440            }          ]        },        "sort" : [          440        ]      },      {        "_index" : "idx2",        "_type" : "_doc",        "_id" : "5",        "_score" : null,        "_source" : {          "hotelId" : 5,          "searchKeywords" : "北京 金融街",          "minPriceCalendar" : [            {              "date" : "2020-11-11",              "minPrice" : 111            },            {              "date" : "2020-11-12",              "minPrice" : 222            },            {              "date" : "2020-11-13",              "minPrice" : 333            },            {              "date" : "2020-11-14",              "minPrice" : 444            }          ]        },        "sort" : [          444        ]      },      {        "_index" : "idx2",        "_type" : "_doc",        "_id" : "4",        "_score" : null,        "_source" : {          "hotelId" : 4,          "searchKeywords" : "北京 西单",          "minPriceCalendar" : [            {              "date" : "2020-11-15",              "minPrice" : 555            }          ]        },        "sort" : [          555        ]      }    ]  }}

注意看sort的值，虽然minPriceCalendar还是把所有价格日历都带出来了，11、12、13号的结果，但是在排序的时候，把它们给过滤了。sort值对比前面的就符合要求了。

Java代码如下：

@GetMapping("/searchKeywordDatePrice")    @ResponseBody    public List searchKeywordDatePrice(@RequestParam() String searchKeywords,            @RequestParam(required = false) String startDate, @RequestParam(required = false) String endDate,            @RequestParam(required = false) Integer minPrice, @RequestParam(required = false) Integer maxPrice)            throws IOException {        if (Strings.isNullOrEmpty(startDate)) {            startDate = "2020-11-11";        }        if (Strings.isNullOrEmpty(endDate)) {            startDate = "2020-11-15";        }        if (Objects.isNull(minPrice)) {            minPrice = 0;        }        if (Objects.isNull(maxPrice)) {            maxPrice = Integer.MAX_VALUE;        }        SearchRequest searchRequest = new SearchRequest("idx2");        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();        BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();        // 关键词        boolQueryBuilder.must(QueryBuilders.matchQuery("searchKeywords", searchKeywords));        // 日期范围        boolQueryBuilder.must(QueryBuilders.nestedQuery("minPriceCalendar",                QueryBuilders.rangeQuery("minPriceCalendar.date").gte(startDate).lte(endDate), ScoreMode.None));        // 价格范围        boolQueryBuilder.must(QueryBuilders.nestedQuery("minPriceCalendar",                QueryBuilders.rangeQuery("minPriceCalendar.minPrice").gte(minPrice).lte(maxPrice), ScoreMode.None));        sourceBuilder.query(boolQueryBuilder);        // 分页        sourceBuilder.from(0);        sourceBuilder.size(10);        // 排序        BoolQueryBuilder nestedBoolQueryBuilder = QueryBuilders.boolQuery();        // 日期范围        nestedBoolQueryBuilder.must(QueryBuilders.rangeQuery("minPriceCalendar.date").gte(startDate).lte(endDate));        // 价格范围        nestedBoolQueryBuilder.must(QueryBuilders.rangeQuery("minPriceCalendar.minPrice").gte(minPrice).lte(maxPrice));        NestedSortBuilder nestedSortBuilder = new NestedSortBuilder("minPriceCalendar");        nestedSortBuilder.setFilter(nestedBoolQueryBuilder);        sourceBuilder.sort(new FieldSortBuilder("minPriceCalendar.minPrice").sortMode(SortMode.MIN).order(SortOrder.ASC)                .setNestedSort(nestedSortBuilder));        searchRequest.source(sourceBuilder);        SearchResponse res = highLevelClient.search(searchRequest, RequestOptions.DEFAULT);        SearchHit[] searchHits = res.getHits().getHits();        Gson gson = new Gson();        List vos = Lists.newArrayList();        for (SearchHit hit : searchHits) {            String sourceAsString = hit.getSourceAsString();            HotelIdx2VO vo = gson.fromJson(sourceAsString, HotelIdx2VO.class);            vo.setMinPrice((int) hit.getSortValues()[0]);            vos.add(vo);        }        return vos;    }

与上一篇文章相比，添加了排序​的代码。

结果：