版本信息记录

本博客记录SpringBoot集成ES相关组件的版本信息如下

名称	版本号
ES服务端	7.14.0
SpringBoot	2.6.13
elasticsearch-rest-high-level-client	7.15.2

温馨提示：部分配置可能因版本而存在差异，比如Java Client API当前版本就和最新版本存在巨大差异。因此具体解决方案请参照官方文档 《Elasticsearch-client》

使用Java API配置ES客户端实现集成

官方文档入口

pom.xml添加相关的Dependency

        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>elasticsearch-rest-high-level-client</artifactId>
        </dependency>

使用javaConfig构建RestHighLevelClient对象

    @Bean
    public RestHighLevelClient restHighLevelClient() {
        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(
                        new HttpHost(esHost, port, schema)));
        return client;
    }

官方提供了如下集群模式下的多节点配置示例：

      RestHighLevelClient client = new RestHighLevelClient(
              RestClient.builder(
                      new HttpHost("localhost", 9200, "http"),
                      new HttpHost("localhost", 9201, "http")));

在此也可以将RequestOptions进行配置

    public static final RequestOptions COMMON_OPTIONS;
    static {
        RequestOptions.Builder builder = RequestOptions.DEFAULT.toBuilder();
        // builder.addHeader("Authorization", "Bearer " + TOKEN);
        // builder.setHttpAsyncResponseConsumerFactory(
        //         new HttpAsyncResponseConsumerFactory
        //                 .HeapBufferedResponseConsumerFactory(30 * 1024 * 1024 * 1024));

        COMMON_OPTIONS = builder.build();
    }

完成的JavaConfig配置如下图所示：

给ES中存储文档数据,当然也可以更新文档数据

首先使用如下代码片段给ES的指定Index中存储文档

    @Test
    void testIndexRequest() throws IOException {
        // 即将存储到ES中的文档
        Product product = new Product("bk-1", "City bike", 123.0);
        // 指定Index
        IndexRequest indexReq = new IndexRequest("product");
        // 给该文档设置id,默认也会自动生成
        indexReq.id(product.getSkuId());
        // 将product实例序列化
        indexReq.source(JSON.toJSONString(product), XContentType.JSON);
        // 进行存储操作
        IndexResponse response = restHighLevelClient.index(indexReq, ElasticSearchConfig.COMMON_OPTIONS);
        System.out.println("response = " + response);
    }

如图所示，存储文档成功；

如果想更新该文档中的数据也可以使用如上代码片段，如图所示

search API:搜索 address 中包含mill的所有人的年龄分布以及平均年龄

    @Test
    void testESSearch() throws IOException {
        // 构建一个查询请求，指定的Index=bank
        SearchRequest searchReq = new SearchRequest("bank");

        // SearchSourceBuilder就是DSL；即检索条件
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        // query match_all
        searchSourceBuilder.query(QueryBuilders.termQuery("address","mill"));
        // 构建age分布的聚合
        TermsAggregationBuilder ageAgg = AggregationBuilders
                .terms("ageAgg").field("age").size(10);
        searchSourceBuilder.aggregation(ageAgg);
        // 构建age的平均聚合
        AvgAggregationBuilder ageAvg = AggregationBuilders
                .avg("ageAvg").field("age");
        searchSourceBuilder.aggregation(ageAvg);

        // 将检索条件封装给查询请求
        searchReq.source(searchSourceBuilder);
        SearchResponse result = restHighLevelClient.search(searchReq, ElasticSearchConfig.COMMON_OPTIONS);
        System.out.println("result = " + result);
    }

search API:按照年龄聚合，并且请求这些年龄段的这些人的平均薪资

    @Test
    void testAgeAvg() throws IOException {
        SearchRequest searchReq = new SearchRequest("bank");

        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        sourceBuilder.query(QueryBuilders.matchAllQuery())
                .aggregation(AggregationBuilders.terms("ageAgg").field("age").size(30)
                        .subAggregation(AggregationBuilders.avg("ageGroupBalanceAvg").field("balance")));
        searchReq.source(sourceBuilder);
        SearchResponse result = restHighLevelClient.search(searchReq, ElasticSearchConfig.COMMON_OPTIONS);
        System.out.println("result = " + result);
    }