版本环境

1. Elasticsearch 6.4.3
2. SpringBoot 2.1.2.RELEASE

引入依赖

    compile group: 'org.elasticsearch.client', name: 'elasticsearch-rest-high-level-client', version: '6.4.3'

配置

其实引入这依赖后, spring-boot-autoconfigure-2.1.2.RELEASE.jar 这个依赖你会为你自动配置 RestHighLevelClient, 而不需要手动创建 RestHighLevelClient

代码具体位置:

org.springframework.boot.autoconfigure.elasticsearch.rest.RestClientAutoConfiguration

    /*
     * Copyright 2012-2018 the original author or authors.
     *
     * Licensed under the Apache License, Version 2.0 (the "License");
     * you may not use this file except in compliance with the License.
     * You may obtain a copy of the License at
     *
     *      http://www.apache.org/licenses/LICENSE-2.0
     *
     * Unless required by applicable law or agreed to in writing, software
     * distributed under the License is distributed on an "AS IS" BASIS,
     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     * See the License for the specific language governing permissions and
     * limitations under the License.
     */

    package org.springframework.boot.autoconfigure.elasticsearch.rest;

    import org.apache.http.HttpHost;
    import org.apache.http.auth.AuthScope;
    import org.apache.http.auth.Credentials;
    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.ObjectProvider;
    import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
    import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
    import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
    import org.springframework.boot.context.properties.EnableConfigurationProperties;
    import org.springframework.boot.context.properties.PropertyMapper;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;

    /**
     * {@link EnableAutoConfiguration Auto-configuration} for Elasticsearch REST clients.
     *
     * @author Brian Clozel
     * @since 2.1.0
     */
    @Configuration
    @ConditionalOnClass(RestClient.class)
    @EnableConfigurationProperties(RestClientProperties.class)
    public class RestClientAutoConfiguration {

        private final RestClientProperties properties;

        private final ObjectProvider<RestClientBuilderCustomizer> builderCustomizers;

        public RestClientAutoConfiguration(RestClientProperties properties,
                ObjectProvider<RestClientBuilderCustomizer> builderCustomizers) {
            this.properties = properties;
            this.builderCustomizers = builderCustomizers;
        }

        @Bean
        @ConditionalOnMissingBean
        public RestClient restClient(RestClientBuilder builder) {
            return builder.build();
        }

        @Bean
        @ConditionalOnMissingBean
        public RestClientBuilder restClientBuilder() {
            HttpHost[] hosts = this.properties.getUris().stream().map(HttpHost::create)
                    .toArray(HttpHost[]::new);
            RestClientBuilder builder = RestClient.builder(hosts);
            PropertyMapper map = PropertyMapper.get();
            map.from(this.properties::getUsername).whenHasText().to((username) -> {
                CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
                Credentials credentials = new UsernamePasswordCredentials(
                        this.properties.getUsername(), this.properties.getPassword());
                credentialsProvider.setCredentials(AuthScope.ANY, credentials);
                builder.setHttpClientConfigCallback((httpClientBuilder) -> httpClientBuilder
                        .setDefaultCredentialsProvider(credentialsProvider));
            });
            this.builderCustomizers.orderedStream()
                    .forEach((customizer) -> customizer.customize(builder));
            return builder;
        }

        @Configuration
        @ConditionalOnClass(RestHighLevelClient.class)
        public static class RestHighLevelClientConfiguration {

            @Bean
            @ConditionalOnMissingBean
            public RestHighLevelClient restHighLevelClient(
                    RestClientBuilder restClientBuilder) {
                return new RestHighLevelClient(restClientBuilder);
            }

        }

    }

不过需要先配置 spring.elasticsearch.rest 配置

    spring:
      elasticsearch:
        rest:
          uris: 
          username: 
          password: 

默认只配置了 hosts 和 username password, 如果要加更多配置的话, 建议重新添加 RestClientBuilder 的配置

当然也可以全部手动配置, 我这里给一个参考:

    package cn.joylau.code.config.elasticsearch.highLevelClient;

    import org.apache.http.HttpHost;
    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 java.util.ArrayList;
    import java.util.List;

    /**
     * Created by joylau on 2020/4/27.
     * cn.joylau.code.config.elasticsearch.highLevelClient
     * 2587038142.liu@gmail.com
     */
    @Configuration
    public class ElasticSearchClient {
        /** 协议 */
        @Value("${elasticsearch.schema:http}")
        private String schema;

        /** 集群地址，如果有多个用“,”隔开 */
        @Value("${elasticsearch.address}")
        private String address;

        /** 连接超时时间 */
        @Value("${elasticsearch.connectTimeout:5000}")
        private int connectTimeout;

        /** Socket 连接超时时间 */
        @Value("${elasticsearch.socketTimeout:10000}")
        private int socketTimeout;

        /** 获取连接的超时时间 */
        @Value("${elasticsearch.connectionRequestTimeout:5000}")
        private int connectionRequestTimeout;

        /** 最大连接数 */
        @Value("${elasticsearch.maxConnectNum:100}")
        private int maxConnectNum;

        /** 最大路由连接数 */
        @Value("${elasticsearch.maxConnectPerRoute:100}")
        private int maxConnectPerRoute;

        @Bean
        public RestHighLevelClient restHighLevelClient() {
            // 拆分地址
            List<HttpHost> hostLists = new ArrayList<>();
            String[] hostList = address.split(",");
            for (String addr : hostList) {
                String host = addr.split(":")[0];
                String port = addr.split(":")[1];
                hostLists.add(new HttpHost(host, Integer.parseInt(port), schema));
            }
            // 转换成 HttpHost 数组
            HttpHost[] httpHost = hostLists.toArray(new HttpHost[]{});
            // 构建连接对象
            RestClientBuilder builder = RestClient.builder(httpHost);
            // 异步连接延时配置
            builder.setRequestConfigCallback(requestConfigBuilder -> {
                requestConfigBuilder.setConnectTimeout(connectTimeout);
                requestConfigBuilder.setSocketTimeout(socketTimeout);
                requestConfigBuilder.setConnectionRequestTimeout(connectionRequestTimeout);
                return requestConfigBuilder;
            });
            // 异步连接数配置
            builder.setHttpClientConfigCallback(httpClientBuilder -> {
                httpClientBuilder.setMaxConnTotal(maxConnectNum);
                httpClientBuilder.setMaxConnPerRoute(maxConnectPerRoute);
                return httpClientBuilder;
            });
            return new RestHighLevelClient(builder);
        }
    }