1. 从 RestHighLevelClient 到 ElasticsearchClient

从 Java Rest Client 7.15.0 版本开始，Elasticsearch 官方决定将 RestHighLevelClient 标记为废弃的，并推荐使用新的 Java API Client，即 ElasticsearchClient. 为什么要将 RestHighLevelClient 废弃，大概有以下几点：

维护成本高：RestHighLevelClient 需要和 Elasticsearch APIs 的更新保持一致，而 Elasticsearch APIs 更新较为频繁，因此每次 Elasticsearch APIs 有新的迭代，RestHighLevelClient 也要跟着迭代，维护成本高。兼容性差: 由于 RestHighLevelClient 和 Elasticsearch 的内部数据结构紧耦合，而 Elasticsearch 不同版本的数据结构可能略有差异，因此很难跨不同版本的 Elasticsearch 保持兼容。灵活度低: RestHighLevelClient 的灵活性扩展性较差，很难去扩展或者自定义一些功能。

而 Spring 官方对 Elasticsearch 客户端也进行了封装，集成于 spring-boot-starter-data-elasticsearch 模块，Elasticsearch 官方决定废弃 RestHighLevelClient 而支持 ElasticsearchClient 这一举措，必然也导致 Spring 项目组对 data-elasticserach 模块进行同步更新，以下是 Spring 成员对相关内容的讨论：

https://github.com/spring-projects/spring-boot/issues/28597

大概内容就是在对 ElasticsearchClient 自动装配的支持会在 springboot 3.0.x 版本中体现，而在 2.7.x 版本中会将 RestHighLevelClient 标记为废弃的。

由于我们的项目是基于 springboot 2.7.10 版本开发的，而 2.7.x 作为最后一个 2.x 版本，springboot 下个版本为 3.x，恰逢项目已经规划在半年后将 JDK 升级为17版本，全面支持 springboot 3.x 版本的替换，因此现阶段需要封装一个能够跨 2.7.x 和 3.x 版本都可以使用的 Elasticsearch 客户端。

2. 自定义 starter 模块实现 ElasticsearchTemplate 的自动装配

在调研了 spring-boot 2.7.10 版本的源码后发现，其实 2.7.x 版本已经引入了 ElasticsearchClient，并封装了新的客户端 ElasticsearchTemplate，但是并没有为其做自动装配，如果想要使用基于ElasticsearchClient 的 ElasticsearchTemplate，需要用户自己装配。否则，直接使用 ElasticsearchTemplate 会出现以下提示：

Consider defining a bean of type 'org.springframework.data.elasticsearch.client.elc.ElasticsearchTemplate' in your configuration.

即由提示可以知道，无法创建一个 ElasticsearchTemplate 类型的 bean.

因此需要自己实现 ElasticsearchTemplate 的装配，才可以使用。为了能够一次装配多项目复用，决定自己构建一个starter，之后需要使用 ElasticsearchTemplate，可以通过引入依赖的方式完成自动装配。

自定义的 starter 项目目录结构如下图所示：

pom.xml 文件：

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">

4.0.0

自定义elasticsearch-client组件

xxx-spring-boot-starters

com.xxx.commons

${revision}

xxx-elasticsearch-client-spring-boot-starter

jar

xxx-elasticsearch-client-spring-boot-starter

org.springframework.boot

spring-boot-starter-data-elasticsearch

jakarta.json

jakarta.json-api

jakarta.json

jakarta.json-api

2.0.1

org.springframework.boot.autoconfigure.AutoConfiguration.imports 文件

com.xxx.commons.springboot.elasticsearch.ElasticsearchTemplateAutoConfiguration

com.xxx.commons.springboot.elasticsearch.actuate.xxxElasticsearchHealthIndicatorAutoConfiguration

PackageInfo 接口：

package com.xxx.commons.springboot.elasticsearch;

/**

* @author reader

* Date: 2023/9/18 22:21

**/

public interface PackageInfo {

}

RestClientBuilder 类：

package com.xxx.commons.springboot.elasticsearch;

import org.apache.commons.lang3.StringUtils;

import org.apache.http.HttpHost;

import org.apache.http.HttpResponseInterceptor;

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.apache.http.message.BasicHeader;

import org.elasticsearch.client.RestClient;

import org.springframework.boot.autoconfigure.elasticsearch.ElasticsearchProperties;

import java.net.URI;

import java.net.URISyntaxException;

/**

* @author reader

* Date: 2023/9/20 15:16

**/

public final class RestClientBuilder {

private RestClientBuilder() {

}

public static RestClient buildWithProperties(ElasticsearchProperties properties) {

HttpHost[] hosts = properties.getUris().stream().map(RestClientBuilder::createHttpHost).toArray((x$0) -> new HttpHost[x$0]);

org.elasticsearch.client.RestClientBuilder builder = RestClient.builder(hosts);

builder.setDefaultHeaders(new BasicHeader[]{new BasicHeader("Content-type", "application/json")});

builder.setHttpClientConfigCallback((httpClientBuilder) -> {

httpClientBuilder.addInterceptorLast((HttpResponseInterceptor) (response, context) -> response.addHeader("X-Elastic-Product", "Elasticsearch"));

if (hasCredentials(properties.getUsername(), properties.getPassword())) {

// 密码配置

CredentialsProvider credentialsProvider = new BasicCredentialsProvider();

credentialsProvider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials(properties.getUsername(), properties.getPassword()));

httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider);

}

// httpClient配置

return httpClientBuilder;

});

builder.setRequestConfigCallback((requestConfigBuilder) -> {

// request配置

requestConfigBuilder.setConnectionRequestTimeout((int)properties.getConnectionTimeout().getSeconds() * 1000);

requestConfigBuilder.setSocketTimeout((int)properties.getSocketTimeout().getSeconds() * 1000);

return requestConfigBuilder;

});

if (properties.getPathPrefix() != null) {

builder.setPathPrefix(properties.getPathPrefix());

}

return builder.build();

}

private static boolean hasCredentials(String username, String password) {

return StringUtils.isNotBlank(username) && StringUtils.isNotBlank(password);

}

private static HttpHost createHttpHost(String uri) {

try {

return createHttpHost(URI.create(uri));

} catch (IllegalArgumentException var2) {

return HttpHost.create(uri);

}

}

private static HttpHost createHttpHost(URI uri) {

if (StringUtils.isBlank(uri.getUserInfo())) {

return HttpHost.create(uri.toString());

} else {

try {

return HttpHost.create((new URI(uri.getScheme(), null, uri.getHost(), uri.getPort(), uri.getPath(), uri.getQuery(), uri.getFragment())).toString());

} catch (URISyntaxException var2) {

throw new IllegalStateException(var2);

}

}

}

}

ElasticsearchClientConfiguration 类：

package com.xxx.commons.springboot.elasticsearch;

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.commons.logging.Log;

import org.apache.commons.logging.LogFactory;

import org.elasticsearch.client.RestClient;

import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;

import org.springframework.boot.autoconfigure.elasticsearch.ElasticsearchProperties;

import org.springframework.boot.context.properties.EnableConfigurationProperties;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

/**

* @author reader

* Date: 2023/9/20 14:59

**/

@Configuration

@EnableConfigurationProperties({ElasticsearchProperties.class})

@ConditionalOnClass({ElasticsearchClient.class, ElasticsearchTransport.class})

public class ElasticsearchClientConfiguration {

protected static final Log LOGGER = LogFactory.getLog(ElasticsearchClientConfiguration.class);

private ElasticsearchProperties elasticsearchProperties;

public ElasticsearchClientConfiguration(ElasticsearchProperties elasticsearchProperties) {

LOGGER.info("框架 elasticsearch-client-starter elasticsearchProperties 装载开始");

this.elasticsearchProperties = elasticsearchProperties;

}

@Bean

public ElasticsearchClient elasticsearchClient() {

LOGGER.info("框架 elasticsearch-client-starter elasticsearchClient 装载开始");

RestClient restClient = RestClientBuilder.buildWithProperties(elasticsearchProperties);

RestClientTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());

return new ElasticsearchClient(transport);

}

}

package com.xxx.commons.springboot.elasticsearch;

import co.elastic.clients.elasticsearch.ElasticsearchClient;

import com.xxx.commons.springboot.elasticsearch.actuate.ElasticsearchInfoContributor;

import org.apache.commons.logging.Log;

import org.apache.commons.logging.LogFactory;

import org.springframework.beans.factory.ObjectProvider;

import org.springframework.boot.actuate.autoconfigure.info.ConditionalOnEnabledInfoContributor;

import org.springframework.boot.autoconfigure.AutoConfiguration;

import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;

import org.springframework.boot.autoconfigure.data.elasticsearch.ElasticsearchDataAutoConfiguration;

import org.springframework.boot.autoconfigure.domain.EntityScanner;

import org.springframework.boot.autoconfigure.elasticsearch.ElasticsearchProperties;

import org.springframework.boot.autoconfigure.elasticsearch.ElasticsearchRestClientAutoConfiguration;

import org.springframework.boot.context.properties.EnableConfigurationProperties;

import org.springframework.context.ApplicationContext;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Import;

import org.springframework.data.elasticsearch.annotations.Document;

import org.springframework.data.elasticsearch.client.elc.ElasticsearchTemplate;

import org.springframework.data.elasticsearch.core.convert.ElasticsearchConverter;

import org.springframework.data.elasticsearch.core.convert.ElasticsearchCustomConversions;

import org.springframework.data.elasticsearch.core.convert.MappingElasticsearchConverter;

import org.springframework.data.elasticsearch.core.mapping.SimpleElasticsearchMappingContext;

import java.util.ArrayList;

import java.util.Collections;

import java.util.List;

/**

* @author reader

* Date: 2023/9/19 16:35

**/

@AutoConfiguration(before = {ElasticsearchRestClientAutoConfiguration.class, ElasticsearchDataAutoConfiguration.class})

@ConditionalOnClass({ElasticsearchTemplate.class})

@EnableConfigurationProperties({ElasticsearchProperties.class})

@Import({ElasticsearchClientConfiguration.class})

public class ElasticsearchTemplateAutoConfiguration {

protected static final Log LOGGER = LogFactory.getLog(ElasticsearchTemplateAutoConfiguration.class);

@Bean

ElasticsearchCustomConversions elasticsearchCustomConversions() {

return new ElasticsearchCustomConversions(Collections.emptyList());

}

@Bean

public SimpleElasticsearchMappingContext elasticsearchMappingContext(ApplicationContext applicationContext,

ElasticsearchCustomConversions elasticsearchCustomConversions) throws ClassNotFoundException {

SimpleElasticsearchMappingContext mappingContext = new SimpleElasticsearchMappingContext();

mappingContext.setInitialEntitySet(new EntityScanner(applicationContext).scan(Document.class));

mappingContext.setSimpleTypeHolder(elasticsearchCustomConversions.getSimpleTypeHolder());

return mappingContext;

}

@Bean

ElasticsearchConverter elasticsearchConverter(SimpleElasticsearchMappingContext mappingContext,

ElasticsearchCustomConversions elasticsearchCustomConversions) {

MappingElasticsearchConverter converter = new MappingElasticsearchConverter(mappingContext);

converter.setConversions(elasticsearchCustomConversions);

return converter;

}

@Bean

ElasticsearchTemplate elasticsearchTemplate(ElasticsearchClient client, ElasticsearchConverter converter) {

LOGGER.info("框架 elasticsearch-client-starter elasticsearchTemplate 装载开始");

return new ElasticsearchTemplate(client, converter);

}

@Bean

@ConditionalOnEnabledInfoContributor("elasticsearch")

public ElasticsearchInfoContributor elasticsearchInfoContributor(ObjectProvider propertiesObjectProvider) {

List properties = new ArrayList<>();

propertiesObjectProvider.forEach(properties::add);

return new ElasticsearchInfoContributor(properties);

}

}

健康度指标相关的封装有：

ElasticsearchHealthIndicator 类：

package com.xxx.commons.springboot.elasticsearch.actuate;

import org.elasticsearch.client.Node;

import org.elasticsearch.client.RestClient;

import org.springframework.boot.actuate.health.AbstractHealthIndicator;

import org.springframework.boot.actuate.health.Health;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import java.util.stream.Collectors;

/**

* @author reader

* Date: 2023/9/20 19:26

**/

public class ElasticsearchHealthIndicator extends AbstractHealthIndicator {

private final List clients;

public ElasticsearchHealthIndicator(List clients) {

this.clients = clients;

}

@Override

protected void doHealthCheck(Health.Builder builder) throws Exception {

boolean success = true;

Map properties = new HashMap<>();

for (RestClient client : clients) {

List nodes = client.getNodes();

if (null == nodes || nodes.isEmpty()){

continue;

}

String id = nodes.stream().map(Node::toString).collect(Collectors.joining(";"));

boolean ps = client.isRunning();

properties.put("ElasticsearchClient[" + id + "]", ps);

if (!ps) {

success = false;

}

}

if (success) {

builder.up();

} else {

builder.withDetails(properties).down();

}

}

}

ElasticsearchInfoContributor 类：

package com.xxx.commons.springboot.elasticsearch.actuate;

import com.xxx.commons.springboot.elasticsearch.PackageInfo;

import org.springframework.boot.actuate.info.Info;

import org.springframework.boot.actuate.info.InfoContributor;

import org.springframework.boot.autoconfigure.elasticsearch.ElasticsearchProperties;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

/**

* @author reader

* Date: 2023/9/20 19:32

**/

public class ElasticsearchInfoContributor implements InfoContributor {

private final List elasticsearchProperties;

public ElasticsearchInfoContributor(List elasticsearchProperties) {

this.elasticsearchProperties = elasticsearchProperties;

}

@Override

public void contribute(Info.Builder builder) {

Map properties = new HashMap<>();

properties.put("version", PackageInfo.class.getPackage().getImplementationVersion());

properties.put("_title_", "ElasticsearchTemplate组件");

elasticsearchProperties.forEach(p -> {

Map sp = new HashMap<>();

String id = String.join(";", p.getUris());

properties.put(id, sp);

sp.put("nodes", String.join(";", p.getUris()));

sp.put("user", p.getUsername());

sp.put("connectionTimeout[ms]", p.getConnectionTimeout().toMillis());

sp.put("socketTimeout[ms]", p.getSocketTimeout().toMillis());

});

builder.withDetail("xxx-elasticsearch-client", properties);

}

}

xxxElasticsearchHealthIndicatorAutoConfiguration 类：

package com.xxx.commons.springboot.elasticsearch.actuate;

import org.elasticsearch.client.RestClient;

import org.springframework.beans.factory.ObjectProvider;

import org.springframework.boot.actuate.autoconfigure.health.ConditionalOnEnabledHealthIndicator;

import org.springframework.boot.actuate.autoconfigure.health.HealthContributorAutoConfiguration;

import org.springframework.boot.autoconfigure.AutoConfiguration;

import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;

import org.springframework.context.annotation.Bean;

import java.util.ArrayList;

import java.util.List;

/**

* @author reader

* Date: 2023/9/20 19:45

**/

@AutoConfiguration(before = {HealthContributorAutoConfiguration.class})

@ConditionalOnEnabledHealthIndicator("elasticsearch")

public class xxxElasticsearchHealthIndicatorAutoConfiguration {

@Bean("elasticsearchHealthIndicator")

@ConditionalOnMissingBean

public ElasticsearchHealthIndicator xxxElasticHealthIndicator(ObjectProvider elasticsearchClientProvider) {

List restClients = new ArrayList<>();

elasticsearchClientProvider.forEach(restClients::add);

return new ElasticsearchHealthIndicator(restClients);

}

}

3. 使用自定义的 starter

1、在自己封装了一个 starter 工具模块之后，通过引入依赖的方式使用，引入的依赖为：

com.xxx.commons

xxx-elasticsearch-client-spring-boot-starter

${version}

在 yaml 文件中配置的相关属性信息：

spring:

elasticsearch:

uris: http://127.0.0.1:9200

username: elastic

password: password

注入并使用 ElasticsearchTemplate 对 ES 进行操作：

package com.xxx.xxx;

import com.xxx.commons.result.query.PaginationBuilder;

import com.xxx.commons.result.query.Query;

import com.xxx.commons.result.query.QueryBuilder;

import com.xxx.push.domain.AliPushRecordDO;

import org.junit.Test;

import org.junit.runner.RunWith;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.boot.test.context.SpringBootTest;

import org.springframework.data.domain.PageRequest;

import org.springframework.data.elasticsearch.client.elc.ElasticsearchTemplate;

import org.springframework.data.elasticsearch.client.elc.NativeQuery;

import org.springframework.data.elasticsearch.client.elc.NativeQueryBuilder;

import org.springframework.data.elasticsearch.core.SearchHit;

import org.springframework.data.elasticsearch.core.SearchHits;

import org.springframework.test.context.junit4.SpringRunner;

import org.springframework.util.CollectionUtils;

import java.util.ArrayList;

import java.util.List;

/**

* @author reader

* Date: 2023/9/26 14:42

**/

@RunWith(SpringRunner.class)

@SpringBootTest(classes = Application.class, properties = {"profile=dev", "debug=true"})

public class ElasticsearchTemplateTest {

@Autowired

private ElasticsearchTemplate elasticsearchTemplate;

@Test

public void testSearch() {

Query query = QueryBuilder.page(1).pageSize(20).build();

NativeQueryBuilder nativeQueryBuilder = new NativeQueryBuilder();

nativeQueryBuilder.withPageable(PageRequest.of(query.getPage() - 1, query.getPageSize()));

NativeQuery searchQuery = nativeQueryBuilder.build();

// 查询总数

long count = elasticsearchTemplate.count(searchQuery, AliPushRecordDO.class);

PaginationBuilder builder = PaginationBuilder.query(query);

builder.amount((int) count);

if (count > 0) {

SearchHits aliPushRecordDOSearchHits = elasticsearchTemplate.search(searchQuery, AliPushRecordDO.class);

List> searchHits = aliPushRecordDOSearchHits.getSearchHits();

List aliPushRecordDOList = new ArrayList<>();

if (!CollectionUtils.isEmpty(searchHits)) {

searchHits.forEach(searchHit -> aliPushRecordDOList.add(searchHit.getContent()));

}

builder.result(aliPushRecordDOList);

} else {

builder.result(new ArrayList<>());

}

}

}

推荐阅读

评论可见，请评论后查看内容，谢谢！！！
 您阅读本篇文章共花了：