环境是springboot是2.3.7，elasticsearch是8.4.3

关于8.4.3的官方文档：https://www.elastic.co/guide/en/elasticsearch/client/java-api-client/8.4/installation.html

问题描述

创建ElasticsearchClient 对象：

一开始报错ClassNotFoundException: jakarta.json.spi.JsonProvider，然后看了下官方文档修改了下jakarta.json-api的版本.解决完成之后报的找不到这个类nested exception is java.lang.NoClassDefFoundError: com/fasterxml/jackson/core/util/JsonProvider。

后来参考了好多博客，最后终于解决了，写下个博客记一下

================================================================

找不到类JsonProvider

项目已经导入：


如果直接导入jakarta.json-api，会出先没有导入成功的结果：还会是默认的1.1.6版本

spring子项目依赖修改父项目依赖问题：必须在下面dependencyManagement中导入正确的依赖

<dependencyManagement>
     <dependencies>
         <dependency>
             <groupId>jakarta.json</groupId>
             <artifactId>jakarta.json-api</artifactId>
             <version>${jakartajson.version}</version>
         </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-dependencies</artifactId>
             <version>${spring-boot.version}</version>
             <type>pom</type>
             <scope>import</scope>
         </dependency>
     </dependencies>
 </dependencyManagement>

其中的jakartajson.version在上面声明

<properties>
     <java.version>1.8</java.version>
     <elasticsearch.version>8.4.3</elasticsearch.version>
     <jackson.version>2.11.3</jackson.version>
     <jakartajson.version>2.0.1</jakartajson.version>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
     <spring-boot.version>2.3.7.RELEASE</spring-boot.version>
 </properties>

刷新，可以看到导入成功

================================================================

找不到类JacksonFeature

是因为

这两个版本号不一致的问题，按照官网推荐，这边在创建springboot项目的时候没有勾选springboot-data-elasticsearch，而在在springboot中默认版本为7.6.2。

解决办法
效仿上面，导入正确的版本8.4.3
properties标签中

<properties>
    <java.version>1.8</java.version>
    <elasticsearch.version>8.4.3</elasticsearch.version>
    <jackson.version>2.11.3</jackson.version>
    <jakartajson.version>2.0.1</jakartajson.version>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <spring-boot.version>2.3.7.RELEASE</spring-boot.version>
</properties>

dependencyManagement标签中

<dependencyManagement>
     <dependencies>
         <dependency>
             <groupId>org.elasticsearch.client</groupId>
             <artifactId>elasticsearch-rest-client</artifactId>
             <version>${elasticsearch.version}</version>
         </dependency>
         <dependency>
             <groupId>jakarta.json</groupId>
             <artifactId>jakarta.json-api</artifactId>
             <version>${jakartajson.version}</version>
         </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-dependencies</artifactId>
             <version>${spring-boot.version}</version>
             <type>pom</type>
             <scope>import</scope>
         </dependency>
     </dependencies>
 </dependencyManagement>

刷新之后，可以看到

最后

关于项目中的完整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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.rui</groupId>
    <artifactId>ElasticSearch_Study</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>ElasticSearch_Study</name>
    <description>ElasticSearch_Study</description>

    <properties>
        <java.version>1.8</java.version>
        <elasticsearch.version>8.4.3</elasticsearch.version>
        <jackson.version>2.11.3</jackson.version>
        <jakartajson.version>2.0.1</jakartajson.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <spring-boot.version>2.3.7.RELEASE</spring-boot.version>
    </properties>

    <dependencies>

        <dependency>
            <groupId>co.elastic.clients</groupId>
            <artifactId>elasticsearch-java</artifactId>
            <version>${elasticsearch.version}</version>
        </dependency>

        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>${jackson.version}</version>
        </dependency>


        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.elasticsearch.client</groupId>
                <artifactId>elasticsearch-rest-client</artifactId>
                <version>${elasticsearch.version}</version>
            </dependency>
            <dependency>
                <groupId>jakarta.json</groupId>
                <artifactId>jakarta.json-api</artifactId>
                <version>${jakartajson.version}</version>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring-boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>2.3.7.RELEASE</version>
                <configuration>
                    <mainClass>com.rui.ElasticSearchStudyApplication</mainClass>
                </configuration>
                <executions>
                    <execution>
                        <id>repackage</id>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

</project>

配置类ElasticSearchClientConfig

package com.rui.config;


import co.elastic.clients.elasticsearch.ElasticsearchClient;
import co.elastic.clients.json.jackson.JacksonJsonpMapper;
import co.elastic.clients.transport.ElasticsearchTransport;
import co.elastic.clients.transport.rest_client.RestClientTransport;
import org.apache.http.HttpHost;
import org.elasticsearch.client.RestClient;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class ElasticSearchClientConfig {
    @Bean
    public ElasticsearchClient elasticsearchClient(){
        RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200)).build();
        ElasticsearchTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());
        //es 客户端
        ElasticsearchClient client = new ElasticsearchClient(transport);
        return client;

    }
}

测试类ElasticSearchStudyApplicationTests

package com.rui;

import co.elastic.clients.elasticsearch.ElasticsearchClient;
import co.elastic.clients.elasticsearch.indices.CreateIndexResponse;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.test.context.SpringBootTest;

import java.io.IOException;

@SpringBootTest
class ElasticSearchStudyApplicationTests {
    @Autowired
    @Qualifier("elasticsearchClient")
    private ElasticsearchClient client;

    //测试索引的创建
    @Test
    void test1() throws IOException {
        //写法比RestHighLevelClient更加简洁
        CreateIndexResponse indexResponse = client.indices().create(c -> c.index("user2"));
    }

}

测试成功

关于具体CRUD的操作，推荐博客：https://blog.csdn.net/yscjhghngh/article/details/123620860