1.直击ES作用

遇到了什么问题?
    随着互联网时代的蓬勃发展,网络上的数据量越来越丰富.用户的需求越来越特殊.
    传统数据库(将数据存放在硬盘上的数据-mysql),不足以支撑复杂的搜索问题.技术的更新势在必行.
哪个技术可以解决这个问题?
    ElasticSearch/solr: 非关系型数据库的一种
        都是基于Lucene封装的.
        Lucene是使用java语言编写的搜索引擎API
这个技术的使用方式?
    安装:
    创建索引库(表):
    mapping映射(字段名,字段类型,字段约束,是否参与搜索..)
    ...

2.ES原理

正向索引

select * from 表名 where age = 18;
执行过程:
    从数据库表中从上到下一条一条的取出数据,如果满足条件则留下此数据,如果不满足条件则忽略数据

倒排索引

倒排索引: 将被搜索的字段逐行遍历,并进行分词,建立词条与文档ID的对应关系

3.ES名词解释

词条(term): 一个中文词语就是一个词条(你好 数据库 我爱你)
文档(Document): 一条数据就是一个文档
索引(Index): 相同类型文档的集合
映射(Mapping): 索引中字段的约束信息
    type: 字段类型
        字符串类型:
            text: 参与分词
            keyword: 不参与分词
    index: 字段是否参与搜索
        默认值为true
    analyzer: 是否分词
        自带:
            standard
        IK:
            ik_smart
            ik_max_word
    properties: 是否有子字段

4.ES使用

操作索引库和文档数据-DSL

# ES启动后就是一个web项目,直接向这个web项目发送RESTFul风格的请求即可操作es.
# RESTFul风格的请求:
#   GET: 查询
#   POST: 添加
#   PUT: 修改
#   DELETE: 删除
DSL
POST /_analyze
{
  "text": "学习java太棒了"
}
​
PUT /house
​
GET /house
​
DELETE /house
​
# ES中自带的分词器叫standard(标准分词器),对中文不友好
POST /_analyze
{
  "text": "中华人民共和国万岁",
  "analyzer": "standard"
}
# 给ES安装ik分词器插件
# ik_smart: 聪明的
# ik_max_word: 最大词汇量分词
POST /_analyze
{
  "text": "中华人民共和国万岁",
  "analyzer": "ik_smart"
}
POST /_analyze
{
  "text": "中华人民共和国万岁",
  "analyzer": "ik_max_word"
}
​
​
POST /_analyze
{
  "text": "哎哟呵奥利给风起来了",
  "analyzer": "ik_max_word"
}
​
# 扩展词
​
# 停用词
​
#=====================索引库操作==================
# 创建索引库
# 创建空索引库
PUT /test
# 创建带有映射关系的索引
PUT /test
{
  "mappings": {
    "properties": {
      "name":{
        "type": "text",
        "index": true,
        "analyzer": "ik_smart"
      },
      "age":{
        "type": "integer",
        "index": true
      },
      "email":{
        "type": "keyword",
        "index": false
      }
    }
  }
}
​
# 查看索引库
GET /test
# 查看索引库的映射信息
GET /test/_mapping
​
# 删除索引库
DELETE /test
​
# 修改索引库(通过修改索引库,添加新字段)
PUT /test/_mapping
{
  "properties":{
    "gender":{
      "type":"keyword"
    }
  }
}
​
#===========================文档操作===================
# 添加文档数据
POST /test/_doc/1
{
  "name":"大幂幂",
  "age":18,
  "gender":"女",
  "email":"damimi@qq.com"
}
POST /test/_doc/1
{
  "name":"大幂幂",
  "age":18,
  "gender":"女",
  "email":"damimi@qq.com"
}
​
POST /test/_doc
{
  "name":"大幂幂2",
  "age":19,
  "gender":"女",
  "email":"damimi2@qq.com"
}
# 根据ID查询文档信息  // 6jP2yIoBwd3FfZ8R0WH0
GET /test/_doc/1
​
GET /test/_doc/XwYKH4kBS7Wd-2ayukAE
​
# 根据ID删除文档数据
DELETE /test/_doc/XwYKH4kBS7Wd-2ayukAE
​
# 修改-全量修改(覆盖)
PUT /test/_doc/1
{
  "name":"大幂幂",
  "age":18,
  "gender":"女",
  "email":"damimi@qq.com"
}
​
# 修改-增量修改(修改指定字段)
POST /test/_update/1
{
  "doc":{
    "name":"柳岩"
  }
}
​

通过java代码操作ES

官网:www.elastic.co/

项目中导入ES依赖

www.elastic.co/guide/en/el…

高版本

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
​
    <groupId>org.example</groupId>
    <artifactId>WindTest</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>pom</packaging>
    <modules>
        <module>es</module>
    </modules>
     <!-- springboot父工程 -->
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.5.5</version>
    </parent>
​
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
        </dependency>
        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>elasticsearch-rest-high-level-client</artifactId>
            <version>7.12.1</version>
        </dependency>
    </dependencies>
​
    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
​
</project>

低版本

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
​
    <groupId>com.bw.es</groupId>
    <artifactId>day0704-01-es</artifactId>
    <version>1.0-SNAPSHOT</version>
    <!-- springboot父工程 -->
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.5.RELEASE</version>
        <relativePath/>
    </parent>
​
    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <!-- 指定导入的es版本 -->
        <elasticsearch.version>7.12.1</elasticsearch.version>
    </properties>
​
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
        </dependency>
        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>elasticsearch-rest-high-level-client</artifactId>
            <version>7.12.1</version>
        </dependency>
    </dependencies>
</project>

创建ES核心对象

并将对象存放到ioc容器中

www.elastic.co/guide/en/el…

package com.wind;
​
import org.apache.http.HttpHost;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import org.springframework.context.annotation.Bean;
​
public class Main {
    public static void main(String[] args) {
        System.out.println("Hello world!");
    }
​
    @Bean
    public RestHighLevelClient createRestHighLevelClient(){
        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(
                        new HttpHost("localhost", 9200, "http")));
        return client;
    }
}

操作索引库

package com.wind.es;

import org.elasticsearch.action.admin.indices.create.CreateIndexRequest;
import org.elasticsearch.action.admin.indices.create.CreateIndexResponse;
import org.elasticsearch.action.admin.indices.delete.DeleteIndexRequest;
import org.elasticsearch.action.support.master.AcknowledgedResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.client.indices.GetIndexRequest;
import org.elasticsearch.client.indices.GetIndexResponse;
import org.elasticsearch.client.indices.PutMappingRequest;
import org.elasticsearch.common.xcontent.XContentType;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;

import javax.annotation.Resource;
import java.io.IOException;
import java.util.Map;

@SpringBootTest
public class test {

    @Resource
    private RestHighLevelClient esClient;

    /*
         //1.创建请求语义对象(本次访问es要做什么操作)
        // 设置请求携带的参数
        //2.发送请求给ES
        // RequestOptions.DEFAULT: 使用默认的请求方式

        3.处理结果信息
        todo:
           java代码操作es的索引库
           创建索引库
           查看索引库
           删除索引库
           修改索引库
     */
    @Test
    //创建
    public void addIndex() throws IOException {
        //1.创建请求语义对象(本次访问es要做什么事情)
        // CreateIndexRequest: 本次请求为的是创建索引
        CreateIndexRequest request = new CreateIndexRequest("test2");
        // 设置请求携带的参数
        request.mapping("_doc", "{\n" + "    "properties": {\n" + "      "name":{\n" + "        "type": "text",\n" + "        "index": true,\n" + "        "analyzer": "ik_smart"\n" + "      },\n" + "      "age":{\n" + "        "type": "integer",\n" + "        "index": true\n" + "      },\n" + "      "email":{\n" + "        "type": "keyword",\n" + "        "index": false\n" + "      }\n" + "    }\n" + "  }", XContentType.JSON);
        //2.发送请求给ES
        // RequestOptions.DEFAULT: 使用默认的请求方式
        CreateIndexResponse response = esClient.indices().create(request, RequestOptions.DEFAULT);
        //3.处理结果信息
        boolean flag = response.isAcknowledged();
        System.out.println(flag);
    }

    @Test
    //查看
    public void getIndex() throws IOException {
        //1.创建请求语义对象(本次访问es要做什么操作)
        GetIndexRequest request = new GetIndexRequest("test2");
        //2.发送请求给ES
        // RequestOptions.DEFAULT: 使用默认的请求方式
        GetIndexResponse response = esClient.indices().get(request, RequestOptions.DEFAULT);
        //3.处理结果信息
        Map<String, Object> map = response.getMappings().get("test2").getSourceAsMap();
        System.out.println(map);
        System.out.println(response);
    }



    @Test
    //修改
    public void updateIndex() throws IOException {
        //1.创建请求语义对象(本次访问es要做什么操作)
        PutMappingRequest request = new PutMappingRequest("test2");

        //构建参数
        request.source(
                "{\n" +
                        "  "properties": {\n" +
                        "    "message": {\n" +
                        "      "type": "text"\n" +
                        "    }\n" +
                        "  }\n" +
                        "}",
                XContentType.JSON);
        //2.发送请求给ES
        // RequestOptions.DEFAULT: 使用默认的请求方式
        AcknowledgedResponse putMappingResponse = esClient.indices().putMapping(request, RequestOptions.DEFAULT);
        //3.处理结果信息
        boolean acknowledged = putMappingResponse.isAcknowledged();
        System.out.println(acknowledged);
    }


    @Test
    //删除
    public void deleteIndex() throws IOException {
        //1.创建请求语义对象(本次访问es要做什么操作)
        DeleteIndexRequest request = new DeleteIndexRequest("test2");

        //2.发送请求给ES
        // RequestOptions.DEFAULT: 使用默认的请求方式
        AcknowledgedResponse deleteIndexResponse = esClient.indices().delete(request, RequestOptions.DEFAULT);
        //3.处理结果信息
        boolean acknowledged = deleteIndexResponse.isAcknowledged();
        System.out.println(acknowledged);
    }

    @Test
    //查看索引是否存在
    public void isOK() throws IOException {
        //1.创建请求语义对象(本次访问es要做什么操作)
        GetIndexRequest request = new GetIndexRequest("test2");

        //2.发送请求给ES
        // RequestOptions.DEFAULT: 使用默认的请求方式
        boolean exists = esClient.indices().exists(request, RequestOptions.DEFAULT);
        //3.处理结果信息
        System.out.println(exists);
    }

}

文档操作

准备工作

application.yml

mybatis-plus:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
    map-underscore-to-camel-case: true

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/wind_test?serverTimezone=GMT%2B8&useUnicode=true&characterEncoding=UTF-8
    username: root
    password: 123456

logging:
  level:
    root: info

 

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.example</groupId>
        <artifactId>WindTest</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

    <groupId>com.wind</groupId>
    <artifactId>es</artifactId>


    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>

        <!--        mysql驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>

<!--        mp依赖-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.5.3.1</version>
        </dependency>

<!--        解析json-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>2.0.32</version>
        </dependency>
        
<!--        减少重复代码插件-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
    </dependencies>



</project>

package com.wind.es;

import com.alibaba.fastjson.JSON;

import com.wind.domain.TestIndex;
import com.wind.service.TestIndexService;
import org.elasticsearch.action.bulk.BulkRequest;
import org.elasticsearch.action.bulk.BulkResponse;
import org.elasticsearch.action.delete.DeleteRequest;
import org.elasticsearch.action.delete.DeleteResponse;
import org.elasticsearch.action.get.GetRequest;
import org.elasticsearch.action.get.GetResponse;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.action.update.UpdateRequest;
import org.elasticsearch.action.update.UpdateResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.xcontent.XContentType;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;

import javax.annotation.Resource;
import java.io.IOException;
import java.util.List;

@SpringBootTest
public class DocTest {

    @Resource
    private RestHighLevelClient client;

    @Resource
    private TestIndexService service;

    /**
     *          //1.创建请求语义对象(本次访问es要做什么操作)
     *         // 设置请求携带的参数
     *         //2.发送请求给ES
     *         // RequestOptions.DEFAULT: 使用默认的请求方式
     *
     *         //3.处理结果信息
     *
     *         todo:
     *            java代码操作es中的文档数据
     *            添加文档数据
     *            查看文档数据
     *            删除文档数据
     *            修改文档数据
     *            for批量插入
     *            bulk批量插入
     *			6zMByYoBwd3FfZ8R_WG4
     */


    @Test
    //添加文档数据
    public void insertDoc() throws IOException {

        //创建请求语义对象
        IndexRequest request = new IndexRequest("test");

        //构建参数
        String jsonString = "{" +
                ""name":"奶茶妹"," +
                ""age":"18"," +
                ""gender":"男"," +
                ""email":"fengqi@163.com"" +
                "}";

        TestIndex testIndex = new TestIndex();
        testIndex.setName("风起");
        testIndex.setAge(18);
        String s = JSON.toJSONString(testIndex);
        request.source(testIndex, XContentType.JSON);

        //发送请求
        IndexResponse response = client.index(request, RequestOptions.DEFAULT);

        //解析返回结果
        System.out.println(response.status());
        System.out.println(response.getResult());

    }

    @Test
    //根据id查看文档
    public void getIndexDoc() throws IOException {

        //创建请求语义对象
        GetRequest request = new GetRequest(
                "test",
                "5DOHyIoBwd3FfZ8Rp2Gv");

        //发送请求
        GetResponse response = client.get(request, RequestOptions.DEFAULT);
        String sourceAsString = response.getSourceAsString();
        System.out.println(sourceAsString);
        TestIndex testIndex = JSON.parseObject(sourceAsString, TestIndex.class);

        System.out.printf("---------------------");
        System.out.println(testIndex);
    }

    //修改
    @Test
    public void updateDoc() throws IOException {

        //创建请求语义对象
        UpdateRequest request = new UpdateRequest("test","5DOHyIoBwd3FfZ8Rp2Gv");

        //构建参数
        TestIndex testIndex = new TestIndex();
        testIndex.setName("吴彦祖");
        testIndex.setAge(111);
        testIndex.setGender("男");
        testIndex.setEmail("吴彦祖163.com");

        String jsonString = "{" +
                ""name":"奶茶妹"," +
                ""age":"18"," +
                ""gender":"男"," +
                ""email":"fengqi@163.com"" +
                "}";

        request.doc(jsonString,XContentType.JSON);

        //发送请求
        UpdateResponse response = client.update(request, RequestOptions.DEFAULT);

        System.out.println(response.status());
    }

    //删除
    @Test
    public  void delDoc() throws IOException {
        //创建请求语义对象
        DeleteRequest request = new DeleteRequest("test", "5DOHyIoBwd3FfZ8Rp2Gv");

        //发送请求给es
        DeleteResponse delete = client.delete(request, RequestOptions.DEFAULT);
        //解析返回结果
        System.out.println(delete.status());
    }

    @Test
    //基于for循环的批量插入
    public void insertListDoc() throws IOException {
        List<TestIndex> list = service.list();

        for (TestIndex testIndex : list) {

            //创建语义对象
            IndexRequest request = new IndexRequest("test");


            //构建参数
            request.id(testIndex.getId()+"");
            request.source(JSON.toJSONString(testIndex),XContentType.JSON);

            //向es发送请求
            IndexResponse response = client.index(request, RequestOptions.DEFAULT);

            //解析结果
            System.out.println(response.status());
        }
    }

    @Test
    public void BulkDoc() throws IOException {

        //创建请求语义对象
        BulkRequest bulkRequest = new BulkRequest("test");

        //mysql中获取数据
        List<TestIndex> list = service.list();

        for (TestIndex testIndex : list) {
            //创建请求语义对象
            IndexRequest request = new IndexRequest();

            //构建参数
            request.source(JSON.toJSONString(testIndex), XContentType.JSON);

            //添加到bulk处理中
            bulkRequest.add(request);
        }

        //向es发送请求
        BulkResponse bulk = client.bulk(bulkRequest, RequestOptions.DEFAULT);
        System.out.println(bulk.status());
    }
}