• Elasticsearch (ES) (上万字）详细学习总结

    一、认识ES

    二、ES相关安装和部署(elasticsearch 、kbana、ik)

    这部分的内容可以查看我之前写的Docker常用部署这篇文章

    三、Mapping映射

    3.1 Mapping映射属性

    3.2 索引库操作 

    3.2.1 遵循Restful规范说明

    3.2.2 具体使用方式说明 

     3.2.3增删改查示例

    1. #创建
    2. PUT /heima
    3. {
    4.   "mappings":{
    5.     "properties": {
    6.       "info":{
    7.         "type": "text",
    8.         "analyzer": "ik_smart"
    9.       },
    10.       "email": {
    11.         "type": "keyword",
    12.         "index": false
    13.       },
    14.       "name": {
    15.         "type": "object",
    16.         "properties": {
    17.           "firstName":{
    18.             "type": "keyword"
    19.           },
    20.           "lastName": {
    21.             "type": "keyword"
    22.           }
    23.         }
    24.       }
    25.     }
    26.   }
    27. }
    28.  
    29. #查询
    30. GET /heima
    31.  
    32. #删除
    33. DELETE /heima
    34.  
    35. #添加
    36. PUT /heima/_mapping
    37. {
    38.   "properties":{
    39.     "age":{
    40.       "type":"byte"
    41.     }
    42.   }
    43. }
    44.

    3.2.4 总结

    3.3 文档的操作

    3.3.1 文档的增删改查示例

    1. #新增文档（如果已经存在则进行修改）
    2. POST /heima/_doc/1
    3. {
    4.   "info": "Java入门到精通",
    5.   "email": "csh@qq.com",
    6.   "name": {
    7.     "firstName": "云",
    8.     "lastName": "赵"
    9.   }
    10. }
    11.  
    12. #查询文档
    13. GET /heima/_doc/1
    14.  
    15. #删除文档
    16. DELETE /heima/_doc/1
    17.  
    18.  
    19. #全量修改（直接覆盖之前的文档，如果不存在该文档则会创建新的文档）
    20. PUT /heima/_doc/1
    21. {
    22.    "info": "Python入门到精通",
    23.   "email": "csh@163.com",
    24.   "name": {
    25.     "firstName": "白",
    26.     "lastName": "李"
    27.   }
    28. }
    29.  
    30. #增量修改（局部修改）
    31. POST /heima/_update/1
    32. {
    33.   "doc":{
    34.     "email":"333@163.com"
    35.   }
    36. }

    3.3.2 文档批量处理

    1. #批量添加
    2. POST /_bulk
    3. {"index": {"_index" : "heima" , "_id":1}}
    4. {"info":"Java入门到精通","email":"csh@qq.com","name":{"firstName": "云","lastName": "赵"}}
    5. {"index": {"_index" : "heima" , "_id":2}}
    6. {"info":"Python入门到精通","email":"csh@163.com","name":{"firstName": "白","lastName": "李"}}
    7.  
    8. #批量删除
    9. POST /heima/_bulk
    10. {"delete": {"_index" : "heima" , "_id":1}}
    11. {"delete": {"_index" : "heima" , "_id":2}}

    3.3.3 总结

    四、JavaRestClient（索引库）

    4.1 客户端初始化

     第一步：

    引入依赖：

    1.         <dependency>
    2.             <groupId>org.elasticsearch.client</groupId>
    3.             <artifactId>elasticsearch-rest-high-level-client</artifactId>
    4.         </dependency>

    第二步：

    在Spring-boot-dependency中找出7.17.0，

    将其复制在父工程的中修改版本号好为7.12.1（可根据自己所需要的版本进行修改）

    第三步：通过RestHighLevelClient使用ES

    建立ES连接示例：
     

    1. package com.etc.search;
    2.  
    3. import org.apache.http.HttpHost;
    4. import org.elasticsearch.client.RestClient;
    5. import org.elasticsearch.client.RestHighLevelClient;
    6. import org.junit.jupiter.api.AfterEach;
    7. import org.junit.jupiter.api.BeforeEach;
    8. import org.junit.jupiter.api.Test;
    9. import org.springframework.boot.test.context.SpringBootTest;
    10.  
    11. import java.io.IOException;
    12.  
    13. @SpringBootTest
    14. class TripSearchApplicationTests {
    15.  
    16.     private RestHighLevelClient client;
    17.  
    18.     @Test
    19.     void testConnection() {
    20.         System.out.println("client: "+client);
    21.     }
    22.  
    23.     @BeforeEach
    24.     void setUp(){
    25.         client = new RestHighLevelClient(RestClient.builder(
    26.                 HttpHost.create("http://192.168.92.136:9200")
    27.         ));
    28.     }
    29.  
    30.     @AfterEach
    31.     void tearDown() throws IOException{
    32.         if(client != null){
    33.             client.close();
    34.         }
    35.     }
    36.  
    37.  
    38. }

    4.2 商品映射Mapping

     kibana创建示例：

    1. PUT /item
    2. {
    3.   "mappings": {
    4.     "properties": {
    5.       "id":{
    6.         "type": "keyword"
    7.       },
    8.       "name":{
    9.         "type": "text",
    10.         "analyzer": "ik_smart"
    11.       },
    12.       "price":{
    13.         "type": "integer"
    14.       },
    15.       "image":{
    16.         "type": "keyword",
    17.         "index": false
    18.       },
    19.       "category":{
    20.         "type":"keyword"
    21.       },
    22.       "brand":{
    23.         "type": "keyword"
    24.       },
    25.       "sold":{
    26.         "type": "integer"
    27.       },
    28.       "commentCount":{
    29.         "type": "integer",
    30.         "index": false
    31.       },
    32.       "isAD":{
    33.         "type": "boolean"
    34.       },
    35.       "updateTime":{
    36.         "type": "date"
    37.       }
    38.     }
    39.   }
    40. }

    4.3 使用Java客户端示例：

    1. package com.etc.search;
    2.  
    3. import org.apache.http.HttpHost;
    4. import org.elasticsearch.action.admin.indices.delete.DeleteIndexRequest;
    5. import org.elasticsearch.client.RequestOptions;
    6. import org.elasticsearch.client.RestClient;
    7. import org.elasticsearch.client.RestHighLevelClient;
    8. import org.elasticsearch.client.indices.CreateIndexRequest;
    9. import org.elasticsearch.client.indices.GetIndexRequest;
    10. import org.elasticsearch.common.xcontent.XContentType;
    11. import org.junit.jupiter.api.AfterEach;
    12. import org.junit.jupiter.api.BeforeEach;
    13. import org.junit.jupiter.api.Test;
    14. import org.springframework.boot.test.context.SpringBootTest;
    15. import org.springframework.web.bind.annotation.DeleteMapping;
    16.  
    17. import java.io.IOException;
    18.  
    19. @SpringBootTest
    20. class TripSearchApplicationTests {
    21.  
    22.     private RestHighLevelClient client;
    23.  
    24.     @Test
    25.     void testConnection() {
    26.         System.out.println("client: "+client);
    27.     }
    28.  
    29.     @Test
    30.     void testCreateIndex() throws IOException{
    31.         CreateIndexRequest request = new CreateIndexRequest("items");
    32.         request.source(MAPPING_TEMPLATE, XContentType.JSON);
    33.         client.indices().create(request, RequestOptions.DEFAULT);
    34.     }
    35.  
    36.     @Test
    37.     void testGetIndex() throws IOException{
    38.         GetIndexRequest request = new GetIndexRequest("items");
    39.         boolean exists =  client.indices().exists(request, RequestOptions.DEFAULT);
    40.         System.out.println("exists:"+exists);
    41.     }
    42.  
    43.     @Test
    44.     void testDeleteIndex() throws IOException{
    45.         DeleteIndexRequest request = new DeleteIndexRequest("items");
    46.  
    47.         client.indices().delete(request, RequestOptions.DEFAULT);
    48.     }
    49.  
    50.     @BeforeEach
    51.     void setUp(){
    52.         client = new RestHighLevelClient(RestClient.builder(
    53.                 HttpHost.create("http://192.168.92.136:9200")
    54.         ));
    55.     }
    56.  
    57.     @AfterEach
    58.     void tearDown() throws IOException{
    59.         if(client != null){
    60.             client.close();
    61.         }
    62.     }
    63.  
    64.     private static final String MAPPING_TEMPLATE = "{\n" +
    65.             "  \"mappings\": {\n" +
    66.             "    \"properties\": {\n" +
    67.             "      \"id\":{\n" +
    68.             "        \"type\": \"keyword\"\n" +
    69.             "      },\n" +
    70.             "      \"name\":{\n" +
    71.             "        \"type\": \"text\",\n" +
    72.             "        \"analyzer\": \"ik_smart\"\n" +
    73.             "      },\n" +
    74.             "      \"price\":{\n" +
    75.             "        \"type\": \"integer\"\n" +
    76.             "      },\n" +
    77.             "      \"image\":{\n" +
    78.             "        \"type\": \"keyword\",\n" +
    79.             "        \"index\": false\n" +
    80.             "      },\n" +
    81.             "      \"category\":{\n" +
    82.             "        \"type\":\"keyword\"\n" +
    83.             "      },\n" +
    84.             "      \"brand\":{\n" +
    85.             "        \"type\": \"keyword\"\n" +
    86.             "      },\n" +
    87.             "      \"sold\":{\n" +
    88.             "        \"type\": \"integer\"\n" +
    89.             "      },\n" +
    90.             "      \"commentCount\":{\n" +
    91.             "        \"type\": \"integer\",\n" +
    92.             "        \"index\": false\n" +
    93.             "      },\n" +
    94.             "      \"isAD\":{\n" +
    95.             "        \"type\": \"boolean\"\n" +
    96.             "      },\n" +
    97.             "      \"updateTime\":{\n" +
    98.             "        \"type\": \"date\"\n" +
    99.             "      }\n" +
    100.             "    }\n" +
    101.             "  }\n" +
    102.             "}";
    103.  
    104.  
    105. }

    4.4 总结

    五、JavaRestClient（文档）

    5.1 使用Java客户端示例：

     示例代码：

    1. package com.etc.search;
    2.  
    3. import org.apache.http.HttpHost;
    4.  
    5. import org.bouncycastle.cert.ocsp.Req;
    6. import org.elasticsearch.action.delete.DeleteRequest;
    7. import org.elasticsearch.action.get.GetRequest;
    8. import org.elasticsearch.action.get.GetResponse;
    9. import org.elasticsearch.action.index.IndexRequest;
    10.  
    11. import org.elasticsearch.action.update.UpdateRequest;
    12. import org.elasticsearch.client.RequestOptions;
    13. import org.elasticsearch.client.RestClient;
    14. import org.elasticsearch.client.RestHighLevelClient;
    15.  
    16. import org.elasticsearch.common.xcontent.XContentType;
    17. import org.junit.jupiter.api.AfterEach;
    18. import org.junit.jupiter.api.BeforeEach;
    19. import org.junit.jupiter.api.Test;
    20. import org.springframework.boot.test.context.SpringBootTest;
    21.  
    22. import java.io.IOException;
    23.  
    24. @SpringBootTest
    25. class TripSearchApplicationTests {
    26.  
    27.     private RestHighLevelClient client;
    28.  
    29.     @Test
    30.     void testConnection() {
    31.         System.out.println("client: "+client);
    32.     }
    33.  
    34.  
    35.     private static final String DOCUMENT_TEMPLATE = "{\n" +
    36.             "  \"id\":\"1\",\n" +
    37.             "  \"name\":\"csh\",\n" +
    38.             "  \"price\":\"11\"\n" +
    39.             "}";
    40.  
    41.     @Test
    42.     void testCreateDocument() throws IOException{
    43.         IndexRequest request = new IndexRequest("items").id("1");
    44.         request.source(DOCUMENT_TEMPLATE,XContentType.JSON);
    45.         client.index(request,RequestOptions.DEFAULT);
    46.     }
    47.  
    48.  
    49.     @Test
    50.     void testDeleteDocument() throws IOException{
    51.         DeleteRequest request = new DeleteRequest("items","1");
    52.  
    53.         client.delete(request,RequestOptions.DEFAULT);
    54.     }
    55.  
    56.     @Test
    57.     void testGetDocument() throws IOException{
    58.         GetRequest request = new GetRequest("items","1");
    59.         GetResponse response =  client.get(request, RequestOptions.DEFAULT);
    60.         String json = response.getSourceAsString();
    61.         System.out.println(json);
    62.     }
    63.  
    64.     @Test
    65.     void testUpdateDocument() throws IOException{
    66.         UpdateRequest request = new UpdateRequest("items","1");
    67.         request.doc(
    68.                 "name","csh2024",
    69.                 "price",2024
    70.         );
    71.         client.update(request,RequestOptions.DEFAULT);
    72.     }
    73.  
    74.     @BeforeEach
    75.     void setUp(){
    76.         client = new RestHighLevelClient(RestClient.builder(
    77.                 HttpHost.create("http://192.168.92.136:9200")
    78.         ));
    79.     }
    80.  
    81.     @AfterEach
    82.     void tearDown() throws IOException{
    83.         if(client != null){
    84.             client.close();
    85.         }
    86.     }
    87.  
    88.  
    89.  
    90. }

    5.2 文档批量操作

    5.3 总结：

     

     六、DSL查询

    6.1 DSL查询介绍

    6.2 DSL查询所有 

    6.3 DSL叶子查询

     match查询单个字段，需要更改key和value的值，而multi_match查询多个字段，key值无需改变。

    6.4 复合查询

    6.4.1 复合查询的bool查询

     6.4.2 复合查询的排序和分页

     示例：先按照销量降序排列，若销量一直则按升序排列

    1. GET /items/_search
    2. {
    3.   "query": {
    4.     "match_all": {}
    5.   },
    6.   "sort": [
    7.     {
    8.       "sold": {
    9.         "order": "desc"
    10.       }, 
    11.       "price": {
    12.         "order": "asc"
    13.       }
    14.     }
    15.   ]
    16. }

     

    from的计算公式：(页数-1)*页条；

    ES对from和size进行限制，两者相加不能超过10000 

     6.5 高亮

    6.6 搜索总结

    七、JavaRestClient （搜索）

    7.1 查询所有

    示例：查询所有（match_all）

    1. package com.etc.search;
    2.  
    3. import org.apache.http.HttpHost;
    4.  
    5. import org.elasticsearch.action.search.SearchRequest;
    6. import org.elasticsearch.action.search.SearchResponse;
    7.  
    8. import org.elasticsearch.client.RequestOptions;
    9. import org.elasticsearch.client.RestClient;
    10. import org.elasticsearch.client.RestHighLevelClient;
    11.  
    12. import org.elasticsearch.index.query.QueryBuilders;
    13. import org.junit.jupiter.api.AfterEach;
    14. import org.junit.jupiter.api.BeforeEach;
    15. import org.junit.jupiter.api.Test;
    16. import org.springframework.boot.test.context.SpringBootTest;
    17.  
    18. import java.io.IOException;
    19.  
    20. @SpringBootTest
    21. class TripSearchApplicationTests {
    22.  
    23.     private RestHighLevelClient client;
    24.  
    25.     @Test
    26.     void testMatchAll() throws IOException{
    27.         SearchRequest request = new SearchRequest("items");
    28.  
    29.         request.source()
    30.                 .query(QueryBuilders.matchAllQuery());
    31.  
    32.         SearchResponse response = client.search(request,RequestOptions.DEFAULT);
    33.         System.out.println("response = "+ response);
    34.     }
    35.  
    36.  
    37.     @BeforeEach
    38.     void setUp(){
    39.         client = new RestHighLevelClient(RestClient.builder(
    40.                 HttpHost.create("http://192.168.92.136:9200")
    41.         ));
    42.     }
    43.  
    44.     @AfterEach
    45.     void tearDown() throws IOException{
    46.         if(client != null){
    47.             client.close();
    48.         }
    49.     }
    50.  
    51.  
    52.  
    53. }

    7.2 解析查询结果

    7.3 构建查询条件

     7.3.1 构建查询条件(matchQuery,multiMatchQuery)

      7.3.2 构建查询条件(termQuery,rangeQuery) 

      7.3.3 构建查询条件(bool查询)  

       示例：使用JavaRestClient实现以下的搜索：

    • 搜索关键字为脱脂牛奶
    • 品牌为德亚
    • 价格必须低于300

    代码：

    1. package com.etc.search;
    2.  
    3. import net.minidev.json.JSONUtil;
    4. import org.apache.http.HttpHost;
    5.  
    6. import org.elasticsearch.action.search.SearchRequest;
    7. import org.elasticsearch.action.search.SearchResponse;
    8.  
    9. import org.elasticsearch.client.RequestOptions;
    10. import org.elasticsearch.client.RestClient;
    11. import org.elasticsearch.client.RestHighLevelClient;
    12.  
    13. import org.elasticsearch.index.query.QueryBuilders;
    14. import org.elasticsearch.search.SearchHit;
    15. import org.elasticsearch.search.SearchHits;
    16. import org.junit.jupiter.api.AfterEach;
    17. import org.junit.jupiter.api.BeforeEach;
    18. import org.junit.jupiter.api.Test;
    19. import org.springframework.boot.test.context.SpringBootTest;
    20.  
    21. import java.io.IOException;
    22.  
    23. @SpringBootTest
    24. class TripSearchApplicationTests {
    25.  
    26.     private RestHighLevelClient client;
    27.  
    28.     @Test
    29.     void testSearch() throws IOException{
    30.         SearchRequest request = new SearchRequest("items");
    31.  
    32.         request.source()
    33.                 .query(QueryBuilders.boolQuery()
    34.                         .must(QueryBuilders.matchQuery("name","脱脂牛奶"))
    35.                         .filter(QueryBuilders.termQuery("brand","德亚"))
    36.                         .filter(QueryBuilders.rangeQuery("price").lt(300)));
    37.  
    38.         SearchResponse response = client.search(request,RequestOptions.DEFAULT);
    39.  
    40.         parseResponseResult(response);
    41.  
    42.  
    43.     }
    44.  
    45.     private static void parseResponseResult(SearchResponse response) {
    46.         //总条数
    47.         SearchHits searchHits = response.getHits();
    48.         long total = searchHits.getTotalHits().value;
    49.         System.out.println("total = "+total);
    50.         //命中条数
    51.         SearchHit[] hits = searchHits.getHits();
    52.         for (SearchHit hit: hits){
    53.             String json = hit.getSourceAsString();
    54.  
    55.             System.out.println("doc = "+ json);
    56.         }
    57.     }
    58.  
    59.  
    60.     @BeforeEach
    61.     void setUp(){
    62.         client = new RestHighLevelClient(RestClient.builder(
    63.                 HttpHost.create("http://192.168.92.136:9200")
    64.         ));
    65.     }
    66.  
    67.     @AfterEach
    68.     void tearDown() throws IOException{
    69.         if(client != null){
    70.             client.close();
    71.         }
    72.     }
    73.  
    74.  
    75.  
    76. }

      7.3.4 排序和分页

    7.4 高亮

    高亮显示结果解析

     示例：解析结果方法

    1. private static void parseResponseResult(SearchResponse response) {
    2.         //总条数
    3.         SearchHits searchHits = response.getHits();
    4.         long total = searchHits.getTotalHits().value;
    5.         System.out.println("total = "+total);
    6.         //命中条数
    7.         SearchHit[] hits = searchHits.getHits();
    8.         for (SearchHit hit: hits){
    9.             String json = hit.getSourceAsString();
    10.             
    11.             //转换为ItemDoc
    12.             ItemDoc doc = JSONUtil.toBean(json,ItemDoc.class);
    13.             
    14.             //处理高亮结果
    15.             Map<String, HighlightField> hfs = hit.getHighlightFields();
    16.             if(hfs != null && !hfs.isEmpty()){
    17.                 HighlightField hf = hfs.get("name");
    18.                 String hfName = hf.getFragments()[0].string();
    19.                 doc.setName(hfName);
    20.             }
    21.             System.out.println("doc = "+ doc);
    22.         }
    23.     }

    八、数据聚合

    8.1 数据聚合的介绍

    注意：参与聚合的字段必须是Keyword、数值、日期、布尔类型的字段 

    8.2 DSL聚合

     

    8.3 JavaRestClient数据聚合 

    1. package com.etc.search;
    2.  
    3. import org.apache.http.HttpHost;
    4.  
    5. import org.elasticsearch.action.search.SearchRequest;
    6. import org.elasticsearch.action.search.SearchResponse;
    7.  
    8. import org.elasticsearch.client.RequestOptions;
    9. import org.elasticsearch.client.RestClient;
    10. import org.elasticsearch.client.RestHighLevelClient;
    11.  
    12. import org.elasticsearch.search.aggregations.AggregationBuilders;
    13. import org.elasticsearch.search.aggregations.Aggregations;
    14. import org.elasticsearch.search.aggregations.bucket.terms.Terms;
    15.  
    16. import org.junit.jupiter.api.AfterEach;
    17. import org.junit.jupiter.api.BeforeEach;
    18. import org.junit.jupiter.api.Test;
    19. import org.springframework.boot.test.context.SpringBootTest;
    20.  
    21. import java.io.IOException;
    22. import java.util.List;
    23. import java.util.Map;
    24.  
    25. @SpringBootTest
    26. class TripSearchApplicationTests {
    27.  
    28.     private RestHighLevelClient client;
    29.  
    30.     @Test
    31.     void testAgg() throws IOException{
    32.         SearchRequest request = new SearchRequest("items");
    33.  
    34.         request.source().size(0);
    35.  
    36.         String brandAggName  = "brandAgg";
    37.  
    38.         request.source().aggregation(
    39.                 AggregationBuilders.terms(brandAggName).field("brand").size(10)
    40.         );
    41.  
    42.         SearchResponse response = client.search(request,RequestOptions.DEFAULT);
    43.  
    44.         Aggregations aggregations = response.getAggregations();
    45.  
    46.         Terms brandTerms  = aggregations.get(brandAggName);
    47.  
    48.         Listextends Terms.Bucket> buckets = brandTerms.getBuckets();
    49.  
    50.         for (Terms.Bucket bucket :buckets){
    51.             System.out.println("brand: "+bucket.getKeyAsString());
    52.             System.out.println("count: "+bucket.getDocCount());
    53.         }
    54.     }
    55.  
    56.     @BeforeEach
    57.     void setUp(){
    58.         client = new RestHighLevelClient(RestClient.builder(
    59.                 HttpHost.create("http://192.168.92.136:9200")
    60.         ));
    61.     }
    62.  
    63.     @AfterEach
    64.     void tearDown() throws IOException{
    65.         if(client != null){
    66.             client.close();
    67.         }
    68.     }
    69.  
    70.  
    71.  
    72. }

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  • 原文地址：https://blog.csdn.net/qq_69183322/article/details/139047704