一、索引库

es中的索引是指相同类型的文档集合，即mysql中表的概念
映射：索引中文档字段的约束，比如名称、类型

1、mapping属性

mapping映射是对索引库中文档的约束。类似mysql对表单字段的约束

{
    "id":[1, 2, 3, 4, 5],
    "name":{
        "firstname":"明",
        "lastname":"李"
    }
}

type：字段数据类型，常见的类型有：
- 字符串：text（可分词的文本）、keyword（不可分词的文本，例如国家、品牌、IP地址）
- 布尔：boolean
- 日期：date
- 数值：long、short、byte、integer、double、float
- Object：对象
  es里面没有数组类型，json格式key、value，允许value有多个值。上图id字段
index：是否创建索引，默认为true。就是是否创建倒排索引，不创建之后就不能通过它搜索。
analyzer：使用那种分词器
properties：该字段的子字段，上面name

2、索引库的crud

# 建立索引库
PUT /linsy
{
  "mappings": {
    "properties": {
      "info": {
        "type": "text",
        "analyzer": "ik_smart"
      },
      "email": {
        "type": "keyword",
        "index": false
      },
      "name": {
        "type": "object",
        "properties": {
          "firstname": {
            "type": "keyword"
          },
          "lastName": {
            "type": "keyword"
          }
        }
      }
    }
  }
}

查询索引库 GET /索引库名 GET /linsy
删除索引库 DELETE /索引库名

ES 禁止修改索引库字段类型及属性，会影响整个索引的结构，但是允许在原有索引库中新增字段。
注意不能新增已有字段

PUT /索引库名/_mapping
{
  "properties": {
    "新字段名": {
      "type": "新字段类型"
    }
  }
}

二、文档的crud

新增操作

POST /索引库名/_doc/文档id
{
  "字段1": "值1“,
  "字段2": "值2",
  "字段3": "值3",
}

查询 GET /索引库名/_doc/文档id
删除 DELETE /索引库名/_doc/文档id

# 文档操作
# 插入
POST /linsy/_doc/1
{
  "age": "11",
  "email": "linsy@linsy.work",
  "info": "this is a first test 文档",
  "name": {
    "firstname": "明",
    "lastName": "李"
  }
}


GET  /linsy/_doc/1

DELETE /linsy/_doc/1

POST /linsy/_update/1
{
  "doc":{
    "age":1111
  }
}

修改文档：

全量修改：删除旧文档，添加新文档。就是将上面新增的 DSL 改为 PUT

PUT /索引库名/_doc/文档id
{
  "字段1": "值1“,
  "字段2": "值2",
  "字段3": "值3",
}

增量修改，修改指定字段

POST /索引库名/_update/文档id
{
  "doc":{
    "字段名":"新的值"
  }
}

三、RestClient

springboot 导入elasticsearch依赖需注意，它默认使用的版本和springboot的版本一致，你需要对应到安装在服务器上的版本。

        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>elasticsearch-rest-high-level-client</artifactId>
        </dependency>

    <properties>
        <java.version>8</java.version>
        <elasticsearch.version>7.17.11</elasticsearch.version>
    </properties>

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创建索引库的mapping映射

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"
      }
    }
  }
}

RestHighLevelClient 的使用
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        RestHighLevelClient restHighLevelClient = new RestHighLevelClient(RestClient.builder(
                HttpHost.create("http://http://192.168.52.150:9200")
        ));

        // index的增删查
        CreateIndexRequest createIndexRequest = new CreateIndexRequest("linsy");
        createIndexRequest.source("建立索引库语句（put）", XContentType.JSON);
        restHighLevelClient.indices().create(createIndexRequest, RequestOptions.DEFAULT);
        restHighLevelClient.indices().delete(new DeleteIndexRequest("要删除的索引库名"), RequestOptions.DEFAULT);
        // 判断是否存在
        boolean b = restHighLevelClient.indices().exists(new GetIndexRequest("索引库名"), RequestOptions.DEFAULT);

es8.x已经弃用了RestHighLevelClient
官方创建RestClient文档

文档的crud
在这里插入图片描述
查询文档

在这里插入图片描述

    @Autowired
    private IHotelService iHotelService;
    
    @BeforeEach
    public void before() {
        restHighLevelClient = new RestHighLevelClient(RestClient.builder(
                HttpHost.create("http://192.168.52.150:9200")
        ));
    }

    @AfterEach
    public void after() throws IOException {
        restHighLevelClient.close();
    }

    @Test
    public void addDocumentTest() throws IOException {
        Hotel hotel = iHotelService.getById(61075);
        HotelDoc hotelDoc = new HotelDoc(hotel);
        IndexRequest indexRequest = new IndexRequest("hotel").id(hotel.getId().toString());
        indexRequest.source(JSON.toJSONString(hotelDoc), XContentType.JSON);
        restHighLevelClient.index(indexRequest, RequestOptions.DEFAULT);
    }

    @Test
    public void queryDocumentTest() throws IOException {
        GetResponse getResponse = restHighLevelClient.get(new GetRequest("hotel", "61075"), RequestOptions.DEFAULT);
        String json = getResponse.getSourceAsString();
        System.out.println(json);
    }

    @Test
    public void updateDocumentTest() throws IOException {
        UpdateRequest updateRequest = new UpdateRequest("hotel", "61075");
        updateRequest.doc(
                "city", "北京",
                "score", "90"
        );
        restHighLevelClient.update(updateRequest, RequestOptions.DEFAULT);
    }

    @Test
    public void deleteDocumentTest() throws IOException {
        restHighLevelClient.delete(new DeleteRequest("hotel", "61075"), RequestOptions.DEFAULT);
    }
    
    @Test
    public void batchAdd() throws IOException {
        BulkRequest bulkRequest = new BulkRequest();

        List<Hotel> list = iHotelService.list();
        for (Hotel hotel : list) {
            HotelDoc hotelDoc = new HotelDoc(hotel);
            bulkRequest.add(new IndexRequest("hotel")
                    .id(hotel.getId().toString())
                    .source(JSON.toJSONString(hotelDoc), XContentType.JSON));

        }
        restHighLevelClient.bulk(bulkRequest, RequestOptions.DEFAULT);
    }