钱小杰的博客
RestClient(1)
编辑
2025-10-02
java
00

目录

1.什么是RestClient
2.实现RestClient案例
3.文档的增删改查
4.文档的批量导入功能
5.elasticsearch搜索功能

1.什么是RestClient

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2.实现RestClient案例

导入数据库 image.png 编写创建索引库的语句

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使用copy_to可以将当前的字段拷贝到其他之中实现同时根据多个字段搜索

DSL
# 酒店的mappings
PUT /hotel
{
  "mappings": {
    "properties": {
      "id":{
        "type":"keyword"
      },
      "name":{
        "type": "text",
        "analyzer": "ik_max_word",
        "copy_to": "all"
      },
      "address":{
        "type": "keyword",
        "index": false
      },
      "price":{
        "type": "integer"
      },
      "score":{
        "type": "integer"
      },
      "brand":{
        "type": "keyword",
        "copy_to": "all"
      },"city":{
        "type": "keyword"
      },"starName":{
        "type": "keyword"
      },"business":{
        "type": "keyword",
        "copy_to": "all"
      },
      "location":{
        "type": "geo_point"
      },
      "pic":{
        "type": "keyword",
        "index": false
        
      }
      ,"all":{
         "type": "text",
        "analyzer": "ik_max_word"
      }
    }
  }
}

初始化项目中的RestClient

image.png

pom
<!--        elasticsearch-->
        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>elasticsearch-rest-high-level-client</artifactId>
            <version>7.12.1</version>
        </dependency>

springboot管理了elasticsearch的版本需要添加覆盖版本 image.png 覆盖版本 image.png 版本全部变为7.12.1（与搭建的elasticsearch一致） image.png 在测试类中编写初始化和销毁代码

java
ublic class HotelIndexTest {
    private RestHighLevelClient client;


    @BeforeEach
    void setUp(){
        this.client = new RestHighLevelClient(RestClient.builder(HttpHost.create("http://192.168.42.10:9200")))
    }
    

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

编写创建索引库代码 image.png

java
    @Test
    void testCreateHotelIndex() throws IOException {
        // 创建request对象
        CreateIndexRequest request = new CreateIndexRequest("hotel");
        // 请求参数
        request.source(MAPPING_TEMPLATE, XContentType.JSON);
        // 发起请求
        client.indices().create(request, RequestOptions.DEFAULT);
    }

编写一个类存放创建索引库的语句

java
package cn.itcast.hotel.constants;

public class HotelConstants {
    public final static String MAPPING_TEMPLATE = "{\n" +
            "  \"mappings\": {\n" +
            "    \"properties\": {\n" +
            "      \"id\":{\n" +
            "        \"type\":\"keyword\"\n" +
            "      },\n" +
            "      \"name\":{\n" +
            "        \"type\": \"text\",\n" +
            "        \"analyzer\": \"ik_max_word\",\n" +
            "        \"copy_to\": \"all\"\n" +
            "      },\n" +
            "      \"address\":{\n" +
            "        \"type\": \"keyword\",\n" +
            "        \"index\": false\n" +
            "      },\n" +
            "      \"price\":{\n" +
            "        \"type\": \"integer\"\n" +
            "      },\n" +
            "      \"score\":{\n" +
            "        \"type\": \"integer\"\n" +
            "      },\n" +
            "      \"brand\":{\n" +
            "        \"type\": \"keyword\",\n" +
            "        \"copy_to\": \"all\"\n" +
            "      },\"city\":{\n" +
            "        \"type\": \"keyword\"\n" +
            "      },\"starName\":{\n" +
            "        \"type\": \"keyword\"\n" +
            "      },\"business\":{\n" +
            "        \"type\": \"keyword\",\n" +
            "        \"copy_to\": \"all\"\n" +
            "      },\n" +
            "      \"location\":{\n" +
            "        \"type\": \"geo_point\"\n" +
            "      },\n" +
            "      \"pic\":{\n" +
            "        \"type\": \"keyword\",\n" +
            "        \"index\": false\n" +
            "        \n" +
            "      }\n" +
            "      ,\"all\":{\n" +
            "         \"type\": \"text\",\n" +
            "        \"analyzer\": \"ik_max_word\"\n" +
            "      }\n" +
            "    }\n" +
            "  }\n" +
            "}";
}

运行代码查询平台创建成功

java
{
  "hotel" : {
    "aliases" : { },
    "mappings" : {
      "properties" : {
        "address" : {
          "type" : "keyword",
          "index" : false
        },
        "brand" : {
          "type" : "keyword"
        },
        "business" : {
          "type" : "keyword"
        },
        "city" : {
          "type" : "keyword"
        },
        "id" : {
          "type" : "keyword"
        },
        "location" : {
          "type" : "geo_point"
        },
        "name" : {
          "type" : "text",
          "analyzer" : "ik_max_word"
        },
        "pic" : {
          "type" : "keyword",
          "index" : false
        },
        "price" : {
          "type" : "integer"
        },
        "score" : {
          "type" : "integer"
        },
        "starName" : {
          "type" : "keyword"
        }
      }
    },
    "settings" : {
      "index" : {
        "routing" : {
          "allocation" : {
            "include" : {
              "_tier_preference" : "data_content"
            }
          }
        },
        "number_of_shards" : "1",
        "provided_name" : "hotel",
        "creation_date" : "1759399676974",
        "number_of_replicas" : "1",
        "uuid" : "aRnUh_l1Thi3hABSvrbm_w",
        "version" : {
          "created" : "7120199"
        }
      }
    }
  }
}

删除索引库判断索引库是否存在

image.png

java
    @Test
    void testGetHotelIndex() throws IOException {
        // 创建request对象
        GetIndexRequest request = new GetIndexRequest("hotel");
        // 发起判断索引库是否存在
        boolean exists = client.indices().exists(request, RequestOptions.DEFAULT);
        // 输出结果
        System.out.println(exists);
    }

java
    @Test
    void testDeleteHotelIndex() throws IOException {
        // 创建request对象
        DeleteIndexRequest request = new DeleteIndexRequest("hotel");
        // 发起删除请求
        client.indices().delete(request, RequestOptions.DEFAULT);
    }

3.文档的增删改查

编写添加文档代码

java
    @Test
    void testInsertIndex() throws IOException {
        // 根据id查询hotel数据
        Hotel hotel= hotelService.getById(36934L);
        //        将hotel转成hotelDoc
        HotelDoc hotelDoc = new HotelDoc(hotel);
//        创建request对象
        IndexRequest request = new IndexRequest("hotel").id(hotelDoc.getId().toString());

        request.source(JSON.toJSONString(hotelDoc),XContentType.JSON);

        client.index(request, RequestOptions.DEFAULT);

    }

添加成功在可视化平台上查询 添加成功

image.png

根据id查询文档

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java
    @Test
    void testGetDocument() throws IOException {
//        创建request对象
        GetRequest request = new GetRequest("hotel","36934");
//        获取response
        GetResponse response = client.get(request, RequestOptions.DEFAULT);
//        解析返回数据
        String json = response.getSourceAsString();
//        打印结果
        HotelDoc hotelDoc = JSON.parseObject(json,HotelDoc.class);
        System.out.println(hotelDoc.toString());
    }

修改文档

java
    @Test
    void testUpdateDocument() throws IOException {
        UpdateRequest request = new UpdateRequest("hotel","36934");
        request.doc("price","952","starName","四钻");
        client.update(request, RequestOptions.DEFAULT);
    }

删除文档

java
    @Test
    void testDeleteDocument() throws IOException {
        DeleteRequest request = new DeleteRequest("hotel","36934");
        client.delete(request, RequestOptions.DEFAULT);
    }

总结

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4.文档的批量导入功能

image.png

代码示例

java
    @Test
    void testRangeIndexDocument() throws IOException {
     // 使用mybatis-plus读取数据库数据
        List<Hotel> hotelList = hotelService.list();
        BulkRequest request = new BulkRequest();
        for (Hotel hotel : hotelList) {
            HotelDoc hotelDoc = new HotelDoc(hotel);
            request.add(new IndexRequest("hotel").id(hotelDoc.getId().toString()).source(JSON.toJSONString(hotelDoc),XContentType.JSON));
        }
        client.bulk(request, RequestOptions.DEFAULT);
    }

5.elasticsearch搜索功能

DSL查询

image.png

基本语法 查询所有 image.png

DSL
GET /hotel/_search
{
  "query":{
  "match_all":{
    
  }
  }
}

全文检索查询（搜索框搜索）

image.png

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使用all搜索设置好的字段

DSL
# match 单字段查询
Get /hotel/_doc/_search
{
  "query":{
    "match":{
      "all":"外滩"
    }
    
  }
}

DSL
# multi_match 多字段查询
Get /hotel/_doc/_search
{
  "query":{
    "multi_match":{
      "query":"外滩如家",
      "fields":["brand","name","business"]
    }
    
  }
}

精确查询

image.png

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DSL
# term查询
GET /hotel/_search
{
  "query": {
    "term": {
      "city" : {
        "value": "北京"
      }
    }
  }
}

价格在 100到300（包含100 300）

DSL
# range
GET /hotel/_search
{
  "query":{
    "range":{
      "price":{
        "gte":100,
        "lte":300
      }
    }
  }
}

价格在 1341到3000（不包含1341 3000）

DSL
GET /hotel/_search
{
  "query":{
    "range":{
      "price":{
        "gt":1341,
        "lt":3000
      }
    }
  }
}

地理查询

geo_bounding_box

image.png

geo_distance

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DSL
GET /hotel/_search
{
  "query":{
    "geo_distance":{
      "distance":"15km",
      "location":"31.21,121.5"
    }
  }
}

复合查询

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控制查询

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控制品牌为如家的酒店放在最上面

DSL
# function score
GET /hotel/_search
{
  "query":{
    "function_score": {
      "query": {
        "match":{
          "all":"外滩"
        }
      },
      "functions": [
        {
          "filter": {
            "term": {
              "brand": "如家"
            }
          },
          "weight": 100
        }
      ],
      "boost_mode": "multiply"
    }
  }
}

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案例

image.png

DSL
GET /hotel/_search
{
  "query":{
    "bool":{
      "must": [
        {
          "match": {
            "name": "如家"
          }
        }
      ],
      "must_not": [
        {
          "range": {
            "price": {
              "gt": 400
            }
          }
        }
      ],
      "filter": [
        {
          "geo_distance": {
            "distance": "10km",
            "location": {
              "lat": 31.21,
              "lon": 121.5
            }
          }
        }
      ]
    }
  }
}

在filter中的内容不参与算分降低性能消耗

本文作者:钱小杰

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