一、索引庫

es中的索引是指相同類型的文檔集合，即mysql中表的概念
映射：索引中文檔字段的約束，比如名稱、類型

1、mapping屬性

mapping映射是對索引庫中文檔的約束。類似mysql對表單字段的約束

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

• type：字段數據類型，常見的類型有：
  • 字符串：text（可分詞的文本）、keyword（不可分詞的文本，例如國家、品牌、IP地址）
  • 布爾：boolean
  • 日期：date
  • 數值：long、short、byte、integer、double、float
  • Object：對象
    es里面沒有數組類型，json格式key、value，允許value有多個值。上圖id字段
• index：是否創建索引，默認為true。就是是否創建倒排索引，不創建之后就不能通過它搜索。
• analyzer：使用那種分詞器
• properties：該字段的子字段，上面name

2、索引庫的crud

# 建立索引庫
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"}}}}}
}

查詢索引庫 GET /索引庫名 GET /linsy
刪除索引庫 DELETE /索引庫名

ES 禁止修改索引庫字段類型及屬性，會影響整個索引的結構，但是允許在原有索引庫中新增字段。
注意不能新增已有字段

PUT /索引庫名/_mapping
{"properties": {"新字段名": {"type": "新字段類型"}}
}

二、文檔的crud

新增操作

POST /索引庫名/_doc/文檔id
{"字段1": "值1“,"字段2": "值2","字段3": "值3",
}

查詢 GET /索引庫名/_doc/文檔id
刪除 DELETE /索引庫名/_doc/文檔id

# 文檔操作
# 插入
POST /linsy/_doc/1
{"age": "11","email": "linsy@linsy.work","info": "this is a first test 文檔","name": {"firstname": "明","lastName": "李"}
}GET  /linsy/_doc/1DELETE /linsy/_doc/1POST /linsy/_update/1
{"doc":{"age":1111}
}

修改文檔：

• 全量修改：刪除舊文檔，添加新文檔。就是將上面新增的 DSL 改為 PUT

PUT /索引庫名/_doc/文檔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 /索引庫名/_update/文檔id
{"doc":{"字段名":"新的值"}
}

三、RestClient

springboot 導入elasticsearch依賴需注意，它默認使用的版本和springboot的版本一致，你需要對應到安裝在服務器上的版本。

        <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>

創建索引庫的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

        RestHighLevelClient restHighLevelClient = new RestHighLevelClient(RestClient.builder(HttpHost.create("http://http://192.168.52.150:9200")));// index的增刪查CreateIndexRequest createIndexRequest = new CreateIndexRequest("linsy");createIndexRequest.source("建立索引庫語句（put）", XContentType.JSON);restHighLevelClient.indices().create(createIndexRequest, RequestOptions.DEFAULT);restHighLevelClient.indices().delete(new DeleteIndexRequest("要刪除的索引庫名"), RequestOptions.DEFAULT);// 判斷是否存在boolean b = restHighLevelClient.indices().exists(new GetIndexRequest("索引庫名"), RequestOptions.DEFAULT);

es8.x已經棄用了RestHighLevelClient
官方創建RestClient文檔

文檔的crud

查詢文檔

    @Autowiredprivate IHotelService iHotelService;@BeforeEachpublic void before() {restHighLevelClient = new RestHighLevelClient(RestClient.builder(HttpHost.create("http://192.168.52.150:9200")));}@AfterEachpublic void after() throws IOException {restHighLevelClient.close();}@Testpublic 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);}@Testpublic void queryDocumentTest() throws IOException {GetResponse getResponse = restHighLevelClient.get(new GetRequest("hotel", "61075"), RequestOptions.DEFAULT);String json = getResponse.getSourceAsString();System.out.println(json);}@Testpublic void updateDocumentTest() throws IOException {UpdateRequest updateRequest = new UpdateRequest("hotel", "61075");updateRequest.doc("city", "北京","score", "90");restHighLevelClient.update(updateRequest, RequestOptions.DEFAULT);}@Testpublic void deleteDocumentTest() throws IOException {restHighLevelClient.delete(new DeleteRequest("hotel", "61075"), RequestOptions.DEFAULT);}@Testpublic 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);}