0.引言

我们之间讲解了springboot整合spring data elasticsearch3.x。但elasticsearch的更新十分活跃，截止目前已经到了8.x版本。而spring data elasticsearch3.x所对应的es版本还是6.8.x

所以今天我们来讲解与spring-data-elasticsearch3.x有较大变化的spring data elasticsearch4.2.x版本如何整合到springboot

1. 版本差异

一些基础的概念性内容本文就不再重复讲解，不了解的可以查看之前的文章

spring data elasticsearch4.2.x与spring data elasticsearch3.x存在不少差异，这里仅列举我们搭建环境所涉及到的

日期类型格式声明

spring-data官方文档中可以看到申明日期类型的格式，DateFormat.none和DateFormat.custom已经被弃用

分片数声明

分片数、刷新时间等参数不再在@Docement中声明，显示已经被弃用

取而代之，在@Setting中声明

Repository声明

ElasticsearchCrudRepository被取消，可以使用ElasticsearchRepository替代，当然在3.x版本中也可以直接使用ElasticsearchRepository

2. 环境搭建

1、创建springboot项目，并引入spring web、lombok、spring-data-elasticsearch依赖

        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-elasticsearch</artifactId>
            <version>4.2.10</version>
        </dependency>

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

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>

        <dependency>
            <groupId>org.reflections</groupId>
            <artifactId>reflections</artifactId>
            <version>0.9.11</version>
        </dependency>

2、修改配置文件

spring:
  application:
    name: es-test4
  elasticsearch:
    rest:
      uris: http://192.168.244.11:9200 # 多个地址用逗号隔开
      username: elastic # es开启了security的需要添加用户名和账户
      password: elastic # es开启了security的需要添加用户名和账户
  jackson:
    date-format: yyyy-MM-dd HH:mm:ss

3、创建实体类

/**
 * @author whx
 * @date 2022/7/2
 */
@Data
@Document(indexName = "user")
@Setting(replicas = 0,shards = 1)
public class User implements Serializable {

    @Id
    private String id;

    @Field(type = FieldType.Text, name = "name",analyzer = "standard")
    private String name;

    @Field(type = FieldType.Keyword, name = "password")
    private String password;

    @Field(type = FieldType.Integer, name = "sex")
    private Integer sex;

    @Field(type = FieldType.Text, name = "address", analyzer = "ik_smart")
    private String address;

    @Field(type = FieldType.Date, name = "create_date", pattern="yyyy-MM-dd HH:mm:ss||strict_date_optional_time||epoch_millis")
    private Date createDate;

    @Field(type = FieldType.Long, name = "role_ids")
    private List<Long> roleIds;

    @Field(type = FieldType.Nested, name = "department_list")
    private List<Department> departmentList;

}

@Data
public class Department implements Serializable {

    @Field(type = FieldType.Long, name = "id")
    private Long id;

    @Field(type = FieldType.Keyword, name = "name")
    private String name;
}

4、创建Repository类，用于实现简单的CRUD，其中的自定义方法可以参考上篇3.x版本的文章介绍

import com.example.estest.entity.User;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.elasticsearch.annotations.Query;
import org.springframework.data.elasticsearch.repository.ElasticsearchRepository;

import java.util.List;

/**
 * @author whx
 * @date 2022/7/2
 */
public interface UserRepository extends ElasticsearchRepository<User,String> {

    User findByName(String name);

    List<User> findAllByName(String name);

    Page<User> findAllByName(String name, Pageable pageable);

    @Query("{\"term\": {\"name\": {\"value\": \"?0\"}}}")
    User queryByName(String name);

}

5、实现Controller

import com.example.estest.entity.User;
import com.example.estest.repository.UserRepository;
import lombok.AllArgsConstructor;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.web.bind.annotation.*;

import java.util.List;

/**
 * @author whx
 * @date 2022/7/2
 */
@RestController
@RequestMapping("user")
@AllArgsConstructor
public class UserController {

    private final UserRepository userRepository;

    @GetMapping("getByName")
    public User getByName(String name){
        return userRepository.findByName(name);
    }

    @GetMapping("getAllByName")
    public List<User> getAllByName(String name){
        return userRepository.findAllByName(name);
    }

    @GetMapping("pageAllByName")
    public Page<User> pageAllByName(String name,int page,int size){
        return userRepository.findAllByName(name,PageRequest.of(page,size));
    }

    @GetMapping("queryByName")
    public User queryByName(String name){
        return userRepository.queryByName(name);
    }

    @PostMapping("save")
    public String add(@RequestBody User user){
        try{
            userRepository.save(user);
            return "保存成功";
        }catch (Exception e){
            e.printStackTrace();
            return "保存失败";
        }
    }

}

6、创建ElasticRestClientConfig配置类，声明RestHighLevelClient和ElasticsearchRestTemplate

import org.apache.http.HttpHost;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.CredentialsProvider;
import org.apache.http.impl.client.BasicCredentialsProvider;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestClientBuilder;
import org.elasticsearch.client.RestHighLevelClient;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.elasticsearch.config.AbstractElasticsearchConfiguration;
import org.springframework.data.elasticsearch.core.ElasticsearchRestTemplate;
import org.springframework.data.elasticsearch.core.convert.ElasticsearchConverter;
import org.springframework.data.elasticsearch.repository.config.EnableElasticsearchRepositories;


import java.time.Duration;

/**
 * @author whx
 * @date 2022/7/2
 */
@Configuration
@EnableElasticsearchRepositories(basePackages = "com.example.estest")
public class ElasticRestClientConfig extends AbstractElasticsearchConfiguration {

    @Value("${spring.elasticsearch.rest.uris}")
    private String url;
    @Value("${spring.elasticsearch.rest.username}")
    private String username;
    @Value("${spring.elasticsearch.rest.password}")
    private String password;

    @Override
    @Bean
    public RestHighLevelClient elasticsearchClient() {
        url = url.replace("http://","");
        String[] urlArr = url.split(",");
        HttpHost[] httpPostArr = new HttpHost[urlArr.length];
        for (int i = 0; i < urlArr.length; i++) {
            HttpHost httpHost = new HttpHost(urlArr[i].split(":")[0].trim(),
                    Integer.parseInt(urlArr[i].split(":")[1].trim()), "http");
            httpPostArr[i] = httpHost;
        }
        final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
        credentialsProvider.setCredentials(AuthScope.ANY,new UsernamePasswordCredentials(username,password));
        RestClientBuilder builder = RestClient.builder(httpPostArr)
                // 异步httpclient配置
                .setHttpClientConfigCallback(httpClientBuilder -> {
                    // 账号密码登录
                    httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider);
                    // httpclient连接数配置
                    httpClientBuilder.setMaxConnTotal(30);
                    httpClientBuilder.setMaxConnPerRoute(10);
                    // httpclient保活策略
                    httpClientBuilder.setKeepAliveStrategy(((response, context) -> Duration.ofMinutes(5).toMillis()));
                    return httpClientBuilder;
                });
        return new RestHighLevelClient(builder);
    }



    @Bean
    public ElasticsearchRestTemplate elasticsearchRestTemplate(RestHighLevelClient elasticsearchClient,ElasticsearchConverter elasticsearchConverter){
        return new ElasticsearchRestTemplate(elasticsearchClient,elasticsearchConverter);
    }
}

7、如果需要启动项目时自动创建索引，还可以添加索引创建类

import lombok.AllArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.reflections.Reflections;
import org.springframework.context.ApplicationListener;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.data.elasticsearch.annotations.Document;
import org.springframework.data.elasticsearch.core.ElasticsearchRestTemplate;
import org.springframework.data.elasticsearch.core.IndexOperations;

import java.util.Set;

/**
 * @author whx
 * @date 2022/7/2
 */
@Configuration
@Slf4j
@AllArgsConstructor
public class ElasticCreateIndexStartUp implements ApplicationListener<ContextRefreshedEvent> {

    private final ElasticsearchRestTemplate restTemplate;

    @Override
    public void onApplicationEvent(ContextRefreshedEvent contextRefreshedEvent){
        log.info("[elastic]索引初始化...");
        Reflections f = new Reflections("com.example.estest.entity");
        Set<Class<?>> classSet = f.getTypesAnnotatedWith(Document.class);
        for (Class<?> clazz : classSet) {
            IndexOperations indexOperations = restTemplate.indexOps(clazz);
            if(!indexOperations.exists()){
                indexOperations.create();
                indexOperations.putMapping();
                log.info(String.format("[elastic]索引%s数据结构创建成功",clazz.getSimpleName()));
            }
        }
        log.info("[elastic]索引初始化完毕");
    }

}

8、启动项目

9、调用保存接口

10、调用查询接口

项目接口正常，环境搭建成功！

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