Elasticsearch/ES教程（17）：RestClient查询文档

查询全部

GET /indexName/_search
{
  "query": {
    "match_all": {
    }
  }
}

全文检索查询

常见的全文检索查询包括：

• match查询：单字段查询
• multi_match查询：多字段查询，任意一个字段符合条件就算符合查询条件

match 语法

GET /indexName/_search
{
  "query": {
    "match": {
      "FIELD": "TEXT"
    }
  }
}

mulit_match语法

GET /indexName/_search
{
  "query": {
    "multi_match": {
      "query": "TEXT",
      "fields": ["FIELD1", " FIELD12"]
    }
  }
}

精准查询

精确查询一般是查找keyword、数值、日期、boolean等类型字段。所以不会对搜索条件分词。常见的有：

• term：根据词条精确值查询
• range：根据值的范围查询

  term查询

  因为精确查询的字段搜是不分词的字段，因此查询的条件也必须是不分词的词条。查询时，用户输入的内容跟自动值完全匹配时才认为符合条件。如果用户输入的内容过多，反而搜索不到数据。

  GET /indexName/_search
  {
  "query": {
    "term": {
      "FIELD": {
        "value": "VALUE"
      }
    }
  }
  }
  

range查询

范围查询，一般应用在对数值类型做范围过滤的时候。比如做价格范围过滤。

GET /indexName/_search
{
  "query": {
    "range": {
      "FIELD": {
        "gte": 10, // 这里的gte代表大于等于，gt则代表大于
        "lte": 20 // lte代表小于等于，lt则代表小于
      }
    }
  }
}

完整代码

package cn.bdbk.hotel;

import cn.bdbk.hotel.pojo.HotelDoc;
import com.alibaba.fastjson.JSON;
import org.apache.http.HttpHost;
import org.elasticsearch.action.admin.indices.delete.DeleteIndexRequest;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.client.indices.CreateIndexRequest;
import org.elasticsearch.client.indices.GetIndexRequest;
import org.elasticsearch.common.xcontent.XContentType;
import org.elasticsearch.index.query.QueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

import java.io.IOException;


public class HotelSearchTest {

    private RestHighLevelClient client;

    @Test
    void testMatchAll() throws IOException {
        //准备request
        SearchRequest request = new SearchRequest("hotel");
        //准备dsl
        request.source().query(QueryBuilders.matchAllQuery());
        //发送请求
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        //解析响应
        SearchHits searchHits = response.getHits();
        //获取总条数
        long total = searchHits.getTotalHits().value;
        //获取文档数组
        SearchHit[] searchHit = searchHits.getHits();
        for (SearchHit hit : searchHit){
            //获取文档source
            String json = hit.getSourceAsString();
            //反序列化
            HotelDoc hotelDoc = JSON.parseObject(json, HotelDoc.class);
            System.out.println(hotelDoc);
        }
        System.out.println(total);
    }

    @BeforeEach
    void setUP(){
        this.client = new RestHighLevelClient(RestClient.builder(
                HttpHost.create("http://170.106.116.159:9200")
        ));
    }

    @AfterEach
    void tearTown() throws IOException {
        this.client.close();
    }

}