【尚硅谷】ElasticSearch入门到精通2021最新教程

一、ElasticSearch概述

ElasticSearch是一个分布式，RESTFUL风格的搜索和数据分析引擎

二、Elasticsearch 安装

下载地址：

https://www.elastic.co/cn/downloads/past-releases#elasticsearch

1、选择windows7.8.0版本解压到本地

2、解压后，进入 bin 文件目录，点击 elasticsearch.bat 文件启动 ES 服务

ES目录结构详解

注意：9300 端口为 Elasticsearch 集群间组件的通信端口，9200 端口为浏览器访问的 http 协议 RESTful 端口。

3、打开浏览器（推荐使用谷歌浏览器），输入地址：http://localhost:9200，测试结果

三、Elasticsearch 基本操作

1、索引操作

1）创建索引

PUT http://127.0.0.1:9200/shopping

重复创建索引会报错

【注意】创建索引只能使用PUT请求

2）查看所有索引

GET http://127.0.0.1:9200/_cat/indices?v

3）查看单个索引

GET http://127.0.0.1:9200/shopping

4）删除索引

2、文档操作

1）创建文档

POST请求和PUT请求都可以创建文档

创建文档时，POST可以携带ID也可以不携带ID，但是PUT请求必须要携带ID

创建文档时，POST请求携带ID，如果ES中有相同的文档，则为修改，但是version一直增加

创建文档时，PUT请求携带ID，如果ES中有相同的文档，则为修改，但是version不会增加

2）查看文档（根据ID查看文档）

3）修改文档（全量覆盖）

4）修改文档字段（局部字段更新）

注意requestbody格式

5）删除文档

6）根据条件删除文档

3、映射操作

1）创建映射

PUT http://127.0.0.1:9200/student/_mapping
{
     "properties": {
         "name":{
             "type": "text",
             "index": true
         },
         "sex":{
             "type": "text",
             "index": false
         },
         "age":{
             "type": "long",
             "index": false
         }
     }
}

映射字段说明：

字段名：任意填写，下面指定许多属性，例如：title、subtitle、images、price

type：类型，Elasticsearch 中支持的数据类型非常丰富，说几个关键的：

String 类型，又分两种：
text：可分词

keyword：不可分词，数据会作为完整字段进行匹配

Numerical：数值类型，分两类

基本数据类型：long、integer、short、byte、double、float、half_float
浮点数的高精度类型：scaled_float

Date：日期类型

Array：数组类型

Object：对象

index：是否索引，默认为 true，也就是说你不进行任何配置，所有字段都会被索引。

true：字段会被索引，则可以用来进行搜索
false：字段不会被索引，不能用来搜索

store：是否将数据进行独立存储，

默认为 false 原始的文本会存储在_source 里面，默认情况下其他提取出来的字段都不是独立存储的，是从_source 里面提取出来的。当然你也可以独立的存储某个字段，只要设置 "store": true 即可，获取独立存储的字段要比从_source 中解析快得多，但是也会占用更多的空间，所以要根据实际业务需求来设置。

analyzer：分词器，这里的 ik_max_word 即使用 ik 分词器

2）查看映射

GET http://127.0.0.1:9200/student/_mapping

4、高级查询

1）查询所有文档 match_all

http://127.0.0.1:9200/shopping/_search
{
    "query":{
        "match_all":{}    
    }
}

2）匹配查询 match

http://127.0.0.1:9200/shopping/_search
{
    "query":{
        "match":{
            "title":"手机"
        }
    }
}

3）多字段匹配查询

http://127.0.0.1:9200/shopping/_search
{
     "query": {
         "multi_match": {
             "query": "手机",
             "fields": ["title","category"]
          }
     }
}

4）关键字精确查询 term

term 查询，精确的关键词匹配查询，不对查询条件进行分词。

http://127.0.0.1:9200/shopping/_search
{
     "query": {
         "term": {
             "title":{
                 "value":"小米手机"
             }
          }
     }
}

5）多关键字精确查询 term

terms 查询和 term 查询一样，但它允许你指定多值进行匹配。如果这个字段包含了指定值中的任何一个值，那么这个文档满足条件

http://127.0.0.1:9200/shopping/_search
{
     "query": {
         "term": {
             "title":["小米","华为"]
          }
     }
}

6）指定查询字段 _source

http://127.0.0.1:9200/shopping/_search
{
     "_source": ["name","nickname"], 
     "query": {
         "terms": {
            "title": ["小米"]
         }
     }
}

也可以通过

includes：来指定想要显示的字段

excludes：来指定不想要显示的字段

http://127.0.0.1:9200/shopping/_search
{
     "_source": {
        "includes": ["name","nickname"]
     }, 
     "query": {
         "terms": {
             "nickname": ["zhangsan"]
         }
     }
}

7）组合查询 bool

8）范围查询 range

http://127.0.0.1:9200/shopping/_search
{
     "query": {
         "range": {
             "age": {
                 "gte": 30,
                 "lte": 35
             }
         }
     }
}

9）模糊查询 fuzzy

返回包含与搜索字词相似的字词的文档。

为了找到相似的术语，fuzzy 查询会在指定的编辑距离内创建一组搜索词的所有可能的变体或扩展。然后查询返回每个扩展的完全匹配

http://127.0.0.1:9200/shopping/_search
{
     "query": {
         "fuzzy": {
             "title": {
                "value": "zhangsan"
             }
         }
     }
}

10）字段排序 sort

http://127.0.0.1:9200/shopping/_search
{
    "query":{
        "match":{
            "name":"zhangsan"
        }
    },
    "sort":[
        {
            "age":{
                "order":"desc"
            }
        }
    ]
}

11）高亮查询 highlight

在进行关键字搜索时，搜索出的内容中的关键字会显示不同的颜色，称之为高亮

Elasticsearch 可以对查询内容中的关键字部分，进行标签和样式(高亮)的设置。在使用 match 查询的同时，加上一个 highlight 属性：

pre_tags：前置标签

post_tags：后置标签

fields：需要高亮的字段

12）分页查询

from：当前页的起始索引，默认从 0 开始。 from = (pageNum - 1) * size

size：每页显示多少条

http://127.0.0.1:9200/shopping/_search
{
     "query": {
        "match_all": {}
     },
     "from": 0,
     "size": 2
}

13）聚合查询

①、求最大值

http://127.0.0.1:9200/shopping/_search
{
     "aggs":{
         "max_age":{
             "max":{"field":"age"}
         }
     }
}

②、求最小值

http://127.0.0.1:9200/shopping/_search
{
     "aggs":{
         "min_age":{
             "min":{"field":"age"}
         }
     }
}

③、对字段求和

http://127.0.0.1:9200/shopping/_search
{
     "aggs":{
         "sum_age":{
             "sum":{"field":"age"}
         }
     }
}

④、求平均值

http://127.0.0.1:9200/shopping/_search
{
     "aggs":{
         "avg_age":{
             "avg":{"field":"age"}
         }
     }
}

⑤、State 聚合

stats 聚合，对某个字段一次性返回 count，max，min，avg 和 sum 五个指标

http://127.0.0.1:9200/shopping/_search
{
     "aggs":{
         "stats_age":{
             "stats":{"field":"price"}
         }
     }
}

⑥、桶聚合查询

桶聚和相当于 sql 中的 group by 语句

terms聚合，分组统计

http://127.0.0.1:9200/shopping/_search
{
     "aggs":{
         "price_agg":{
             "terms":{"field":"price"}
         }
     }
}

四、Java操作 ElasticSearch

1、引入pom文件

<dependencies>
    <dependency>
        <groupId>org.elasticsearch</groupId>
        <artifactId>elasticsearch</artifactId>
        <version>7.8.0</version>
    </dependency>
    <!-- elasticsearch 的客户端 -->
    <dependency>
        <groupId>org.elasticsearch.client</groupId>
        <artifactId>elasticsearch-rest-high-level-client</artifactId>
        <version>7.8.0</version>
    </dependency>
    <!-- elasticsearch 依赖 2.x 的 log4j -->
    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-api</artifactId>
        <version>2.8.2</version>
    </dependency>
    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-core</artifactId>
        <version>2.8.2</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.9.9</version>
    </dependency>
    <!-- junit 单元测试 -->
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
    </dependency>
</dependencies>

2、创建es客户端

public class EsTestClient {
    public static void main(String[] args) throws IOException {

        //创建Es客户端
        RestHighLevelClient client =
                new RestHighLevelClient(RestClient.builder(new HttpHost("127.0.0.2", 9200, "http")));

        System.out.println(client);
        //关闭Es客户端
        client.close();
    }
}

3、索引操作

1）创建索引

public class EsTestClient {
    public static void main(String[] args) throws IOException {

        //创建Es客户端
        RestHighLevelClient client =
                new RestHighLevelClient(RestClient.builder(new HttpHost("127.0.0.1", 9200, "http")));

        //1、创建索引
        CreateIndexRequest createIndexRequest = new CreateIndexRequest("user");
        CreateIndexResponse createIndexResponse = client.indices().create(createIndexRequest, RequestOptions.DEFAULT);
        boolean acknowledged = createIndexResponse.isAcknowledged();
        System.out.println("创建索引"+ (acknowledged ? "成功":"失败"));

        //关闭Es客户端
        client.close();
    }
}

在postman中查询

2）查看索引

//2、查看索引
GetIndexRequest getIndexResponse = new GetIndexRequest("user");
GetIndexResponse getIndexResponse = client.indices().get(getIndexRequest, RequestOptions.DEFAULT);

3）删除索引

//3、删除索引
DeleteIndexRequest deleteIndexRequest = new DeleteIndexRequest("user");
AcknowledgedResponse deleteResponse = client.indices().delete(deleteIndexRequest, RequestOptions.DEFAULT);

4、文档操作

1）插入文档

public class EsTestDocInsert {

    public static void main(String[] args) throws IOException {

        //创建Es客户端
        RestHighLevelClient client =
                new RestHighLevelClient(RestClient.builder(new HttpHost("127.0.0.1", 9200, "http")));

        //1、插入文档
        IndexRequest indexRequest = new IndexRequest();
        indexRequest.index("user").id("00001");

        User user = new User();
        user.setName("张三");
        user.setAge(15);
        user.setSex("男");

        ObjectMapper mapper = new ObjectMapper();
        String userStr = mapper.writeValueAsString(user);
        indexRequest.source(userStr, XContentType.JSON);
        IndexResponse reponse = client.index(indexRequest, RequestOptions.DEFAULT);

    }

}

2）修改文档

public class EsTestDocUpdate {

    public static void main(String[] args) throws IOException {
        //创建Es客户端
        RestHighLevelClient client =
                new RestHighLevelClient(RestClient.builder(new HttpHost("127.0.0.1", 9200, "http")));
        //1、修改文档
        UpdateRequest updateRequest = new UpdateRequest();
        updateRequest.index("user").id("00001");
        updateRequest.doc(XContentType.JSON,"sex","女的");
        UpdateResponse updateResponse = client.update(updateRequest, RequestOptions.DEFAULT);
        System.out.println(updateResponse.getResult());
    }
}

3）查询文档（根据ID进行查询）

public class EsTestDocGet {

    public static void main(String[] args) throws IOException {
        //创建Es客户端
        RestHighLevelClient client =
                new RestHighLevelClient(RestClient.builder(new HttpHost("127.0.0.1", 9200, "http")));
        //根据ID查询文档
        GetRequest getRequest = new GetRequest();
        getRequest.index("user").id("00001");
        GetResponse res = client.get(getRequest, RequestOptions.DEFAULT);
        System.out.println(res.getSourceAsString());
    }
}

4）删除文档

public class EsTestDocDelete {

    public static void main(String[] args) throws IOException {
        //创建Es客户端
        RestHighLevelClient client =
                new RestHighLevelClient(RestClient.builder(new HttpHost("127.0.0.1", 9200, "http")));
        //根据ID查询文档
        DeleteRequest deleteRequest = new DeleteRequest();
        deleteRequest.index("user").id("00001");
        DeleteResponse res = client.delete(deleteRequest, RequestOptions.DEFAULT);
        System.out.println(res.getResult());
    }
}

5）批量新增

public class EsTestDocInsertBatch {

    public static void main(String[] args) throws IOException {

        //创建Es客户端
        RestHighLevelClient client =
                new RestHighLevelClient(RestClient.builder(new HttpHost("127.0.0.1", 9200, "http")));

        //1、批量插入文档
        BulkRequest bulkRequest = new BulkRequest();
        bulkRequest.add(new IndexRequest().index("user").source(XContentType.JSON, "name","张三"));
        bulkRequest.add(new IndexRequest().index("user").source(XContentType.JSON, "name","李四"));
        bulkRequest.add(new IndexRequest().index("user").source(XContentType.JSON, "name","王五"));
        BulkResponse response = client.bulk(bulkRequest, RequestOptions.DEFAULT);
        System.out.println(response.getItems());
        client.close();
    }
}

5、高级插叙

1）match_all 查询

public class EsTestDocQuery {
    public static void main(String[] args) throws IOException {

        //创建Es客户端
        RestHighLevelClient client =
                new RestHighLevelClient(RestClient.builder(new HttpHost("127.0.0.1", 9200, "http")));
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("user");
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder().query(QueryBuilders.matchAllQuery());
        searchRequest.source(sourceBuilder);
        SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
        SearchHits hits = response.getHits();
        SearchHit[] hits1 = hits.getHits();
        for (SearchHit documentFields : hits1) {
            System.out.println(documentFields);
        }
        client.close();
    }
}

2）分页查询

public class EsTestDocPageQuery {
    public static void main(String[] args) throws IOException {

        //创建Es客户端
        RestHighLevelClient client =
                new RestHighLevelClient(RestClient.builder(new HttpHost("127.0.0.1", 9200, "http")));
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("user");
        // 构建查询的请求体
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        sourceBuilder.query(QueryBuilders.matchAllQuery());
        // 分页查询
        // 当前页其实索引(第一条数据的顺序号)，from
        sourceBuilder.from(0);
        // 每页显示多少条 size
        sourceBuilder.size(2);
        searchRequest.source(sourceBuilder);
        SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
        // 查询匹配
        SearchHits hits = response.getHits();
        System.out.println("took:" + response.getTook());
        System.out.println("timeout:" + response.isTimedOut());
        System.out.println("total:" + hits.getTotalHits());
        System.out.println("MaxScore:" + hits.getMaxScore());
        System.out.println("hits========>>");
        for (SearchHit hit : hits) {
        //输出每条查询的结果信息
            System.out.println(hit.getSourceAsString());
        }
        System.out.println("<<========");
        client.close();
    }
}

3）数据排序

public class EsTestDocSortQuery {
    public static void main(String[] args) throws IOException {

        //创建Es客户端
        RestHighLevelClient client =
                new RestHighLevelClient(RestClient.builder(new HttpHost("127.0.0.1", 9200, "http")));
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("user");
        // 构建查询的请求体
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        sourceBuilder.query(QueryBuilders.matchAllQuery());
        // 排序
        sourceBuilder.sort("age", SortOrder.ASC);
        searchRequest.source(sourceBuilder);
        SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
        // 查询匹配
        SearchHits hits = response.getHits();
        SearchHit[] hits1 = hits.getHits();
        for (SearchHit documentFields : hits1) {
            System.out.println(documentFields);
        }
        client.close();
    }
}

4）过滤字段

public class EsTestDocFilterQuery {
    public static void main(String[] args) throws IOException {
        RestHighLevelClient client =
                new RestHighLevelClient(RestClient.builder(new HttpHost("127.0.0.1", 9200, "http")));
        // 创建搜索请求对象
        SearchRequest request = new SearchRequest();
        request.indices("student");
        // 构建查询的请求体
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        sourceBuilder.query(QueryBuilders.matchAllQuery());
        //查询字段过滤
        String[] excludes = {};
        String[] includes = {"name", "age"};
        sourceBuilder.fetchSource(includes, excludes);
        request.source(sourceBuilder);
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        // 查询匹配
        SearchHits hits = response.getHits();
        System.out.println("took:" + response.getTook());
        System.out.println("timeout:" + response.isTimedOut());
        System.out.println("total:" + hits.getTotalHits());
        System.out.println("MaxScore:" + hits.getMaxScore());
        System.out.println("hits========>>");
        for (SearchHit hit : hits) {
        //输出每条查询的结果信息
            System.out.println(hit.getSourceAsString());
        }
        System.out.println("<<========");
        client.close();
    }
}

5）bool查询

public class EsTestDocFilterQuery {
    public static void main(String[] args) throws IOException {
        RestHighLevelClient client =
                new RestHighLevelClient(RestClient.builder(new HttpHost("127.0.0.1", 9200, "http")));
        // 创建搜索请求对象
        SearchRequest request = new SearchRequest();
        request.indices("student");
        // 构建查询的请求体
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
        // 必须包含
        boolQueryBuilder.must(QueryBuilders.matchQuery("age", "30"));
        // 一定不含
        boolQueryBuilder.mustNot(QueryBuilders.matchQuery("name", "zhangsan"));
        // 可能包含
        boolQueryBuilder.should(QueryBuilders.matchQuery("sex", "男"));
        sourceBuilder.query(boolQueryBuilder);
        request.source(sourceBuilder);
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        // 查询匹配
        SearchHits hits = response.getHits();
        System.out.println("took:" + response.getTook());
        System.out.println("timeout:" + response.isTimedOut());
        System.out.println("total:" + hits.getTotalHits());
        System.out.println("MaxScore:" + hits.getMaxScore());
        System.out.println("hits========>>");
        for (SearchHit hit : hits) {
        //输出每条查询的结果信息
            System.out.println(hit.getSourceAsString());
        }
        System.out.println("<<========");
        client.close();
    }
}

6）范围查询

public class EsTestDocRangeQuery {
    public static void main(String[] args) throws IOException {

        //创建Es客户端
        RestHighLevelClient client =
                new RestHighLevelClient(RestClient.builder(new HttpHost("127.0.0.1", 9200, "http")));
        // 创建搜索请求对象
        SearchRequest request = new SearchRequest();
        request.indices("student");
        // 构建查询的请求体
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        RangeQueryBuilder rangeQuery = QueryBuilders.rangeQuery("age");
        // 大于等于
        rangeQuery.gte("30");
        // 小于等于
        rangeQuery.lte("40");
        sourceBuilder.query(rangeQuery);
        request.source(sourceBuilder);
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        // 查询匹配
        SearchHits hits = response.getHits();
        System.out.println("took:" + response.getTook());
        System.out.println("timeout:" + response.isTimedOut());
        System.out.println("total:" + hits.getTotalHits());
        System.out.println("MaxScore:" + hits.getMaxScore());
        System.out.println("hits========>>");
        for (SearchHit hit : hits) { 
            //输出每条查询的结果信息 
            System.out.println(hit.getSourceAsString()); 
        } 
        System.out.println("<<========");
        client.close();
    }
}

7）模糊查询

// 创建搜索请求对象
SearchRequest request = new SearchRequest();
request.indices("student");
// 构建查询的请求体
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
sourceBuilder.query(QueryBuilders.fuzzyQuery("name","zhangsan").fuzziness(Fu
        zziness.ONE));
request.source(sourceBuilder);
SearchResponse response = client.search(request, RequestOptions.DEFAULT);
// 查询匹配
SearchHits hits = response.getHits();
System.out.println("took:" + response.getTook());
System.out.println("timeout:" + response.isTimedOut());
System.out.println("total:" + hits.getTotalHits());
System.out.println("MaxScore:" + hits.getMaxScore());
System.out.println("hits========>>");
for (SearchHit hit : hits) {
//输出每条查询的结果信息
    System.out.println(hit.getSourceAsString());
}
System.out.println("<<========");

8）高亮查询

// 高亮查询
SearchRequest request = new SearchRequest().indices("student");
//2.创建查询请求体构建器
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
//构建查询方式：高亮查询
TermsQueryBuilder termsQueryBuilder =
        QueryBuilders.termsQuery("name","zhangsan");
//设置查询方式
sourceBuilder.query(termsQueryBuilder)
//构建高亮字段
HighlightBuilder highlightBuilder = new HighlightBuilder();
highlightBuilder.preTags("<font color='red'>");//设置标签前缀
highlightBuilder.postTags("</font>");//设置标签后缀
highlightBuilder.field("name");//设置高亮字段
//设置高亮构建对象
sourceBuilder.highlighter(highlightBuilder);
//设置请求体
request.source(sourceBuilder);
//3.客户端发送请求，获取响应对象
SearchResponse response = client.search(request, RequestOptions.DEFAULT);
//4.打印响应结果
SearchHits hits = response.getHits();
System.out.println("took::"+response.getTook());
System.out.println("time_out::"+response.isTimedOut());
System.out.println("total::"+hits.getTotalHits());
System.out.println("max_score::"+hits.getMaxScore());
System.out.println("hits::::>>");
for (SearchHit hit : hits) {
    String sourceAsString = hit.getSourceAsString();
    System.out.println(sourceAsString);
//打印高亮结果
    Map<String, HighlightField> highlightFields = hit.getHighlightFields();
    System.out.println(highlightFields);
}
System.out.println("<<::::");

9）聚合查询

① 最大值

public class EsTestDocMaxAggregation {
    public static void main(String[] args) throws IOException {

        //创建Es客户端
        RestHighLevelClient client =
                new RestHighLevelClient(RestClient.builder(new HttpHost("127.0.0.1", 9200, "http")));
        SearchRequest request = new SearchRequest();
        request.indices("user");
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        sourceBuilder.aggregation(AggregationBuilders.max("maxAge").field("age"));
        //设置请求体
        request.source(sourceBuilder);
        //3.客户端发送请求，获取响应对象
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        //4.打印响应结果
        SearchHits hits = response.getHits();
        System.out.println(response);
        client.close();
    }
}

② 分组聚合

public class EsTestDocMaxAggregation {
    public static void main(String[] args) throws IOException {

        //1创建Es客户端
        RestHighLevelClient client =
                new RestHighLevelClient(RestClient.builder(new HttpHost("127.0.0.1", 9200, "http")));
        SearchRequest request = new SearchRequest();
        request.indices("user");
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        sourceBuilder.aggregation(AggregationBuilders.terms("age_groupby").field("age"));
        //设置请求体
        request.source(sourceBuilder);
        //3.客户端发送请求，获取响应对象
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        //4.打印响应结果
        SearchHits hits = response.getHits();
        System.out.println(response);
        client.close();
    }
}

posted @ 2021-08-11 08:01 青岑阅读(1067) 评论(0) 编辑收藏举报

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