ElasticSearch 8.x 版本如何使用 SearchRequestBuilder 检索
创始人
2024-11-15 06:38:17
0

ElasticSearch

1、ElasticSearch学习随笔之基础介绍
2、ElasticSearch学习随笔之简单操作
3、ElasticSearch学习随笔之java api 操作
4、ElasticSearch学习随笔之SpringBoot Starter 操作
5、ElasticSearch学习随笔之嵌套操作
6、ElasticSearch学习随笔之分词算法
7、ElasticSearch学习随笔之高级检索
8、ELK技术栈介绍
9、Logstash部署与使用
10、ElasticSearch 7.x 版本使用 BulkProcessor 实现批量添加数据
11、ElasticSearch 8.x 弃用了 High Level REST Client,移除了 Java Transport Client,推荐使用 Elasticsearch Java API
12、ElasticSearch 8.x 使用 snapshot(快照)进行数据迁移
13、ElasticSearch 8.x 版本如何使用 SearchRequestBuilder 检索
14、ElasticSearch 8.x 使用 High Level Client 以 HTTPS 方式链接,SSL 证书、主机名验证器 各是什么,如何忽略
15、ElasticSearch 8.x 创建父子文档,用Join类型字段以及用has_child、has_parent 检索
16、ElasticSearch如何提高写入效率【面试题,面道既学到】

ElasticSearch,创始人 Shay Banon(谢巴农)
本文主要讲解ElasticSearch 高级搜索实战,来满足复杂的业务场景,还是用 Kibana 来操作。


文章目录

  • ElasticSearch
  • 前言
  • 一:pom 依赖
  • 二:初始化客户端
    • 2.1 初始化 HighLevelClient 客户端
    • 2.2 初始化 ElasticsearchClient 客户端
  • 三:执行查询


前言

在之前的项目中都是用 SearchRequestBuilder 来构件 ElasticSearch 检索请求的,然后使用了新的 High Level Client 之后新的客户端构建查询是用了 SearchSourceBuilder 来构建检索请求的,若使使用新的检索方式请移步《Elasticsearch Java API 如何使用》查看。
那用 SearchSourceBuilder 进行构建查询时需要使用 RestHighLevelClient 客戶端来发送请求的,简单代码如下:

RestHighLevelClient client = createClient(); SearchRequest searchRequest = new SearchRequest(); SearchSourceBuilder sourceBuilder = new SearchSourceBuilder(); sourceBuilder.query(QueryBuilders.matchAllQuery()); searchRequest.source(sourceBuilder); sourceBuilder.from(0).size(10); SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT); 

以上这种写法就是 High Level Client 常见的写法。
那如果特殊情况下,比如需要和老项目融合的时候,可能需要使用到 SearchRequestBuilder 来检索,该如何做呢?
就是用 ElasticsearchClient 来包装 RestHighLevelClient 来执行查询,真正的检索使用 RestHighLevelClient 来执行的,而 ElasticsearchClient 则是构建为了融合并初始化 SearchRequestBuilder 而创建的。

一:pom 依赖

     org.elasticsearch.client     elasticsearch-rest-high-level-client     7.17.16  

二:初始化客户端

2.1 初始化 HighLevelClient 客户端

这里首先要初始化 HighLevelClient 客户端,因为真正的检索需要使用此客户端来执行的。

/**  * 初始化客户端  * @return RestHighLevelClient  */ private static RestHighLevelClient getClient(){     final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();     credentialsProvider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials("Your username", "Your password"));     RestClientBuilder restClientBuilder = RestClient.builder(new HttpHost("192.168.*.*", 9200))             .setHttpClientConfigCallback(httpAsyncClientBuilder -> httpAsyncClientBuilder.setDefaultCredentialsProvider(credentialsProvider));     RestHighLevelClient highLevelClient = new RestHighLevelClient(restClientBuilder);     return highLevelClient; } 

2.2 初始化 ElasticsearchClient 客户端

这里我们来初始化 ElasticsearchClient 客户端,为什么要初始化此客户端呢?ElasticsearchClient 就像是一个代理客户端,调用了 HighLevelClient 来执行查询。
这里,我们把 RestHighLevelClient 作为参数传入,用于封装。

private static ElasticsearchClient getEsClient(RestHighLevelClient highLevelClient){     return new ElasticsearchClient() {         @Override         public  ActionFuture execute(ActionType action, Request request) {             if (action.equals(SearchAction.INSTANCE) && request instanceof SearchRequest) {                 return new ActionFuture() {                     @Override                     public Response actionGet() {                         try {                         	// 执行检索                             return (Response) highLevelClient.search((SearchRequest) request, RequestOptions.DEFAULT);                         } catch (IOException e) {                             e.printStackTrace();                         }                         return null;                     }                      @Override                     public Response actionGet(String timeout) {                         try {                             // 将字符串形式的时间转换为 TimeValue                             TimeValue timeValue = TimeValue.parseTimeValue(timeout, "timeout");                             SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();                             sourceBuilder.timeout(timeValue);                             SearchRequest searchRequest = new SearchRequest();                             searchRequest.source(sourceBuilder);                             // 执行检索                             return (Response) highLevelClient.search((SearchRequest) request, RequestOptions.DEFAULT);                         } catch (IOException e) {                             throw new RuntimeException(e);                         }                     }                      @Override                     public Response actionGet(long timeoutMillis) {                         try {                             SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();                             sourceBuilder.timeout(TimeValue.timeValueMillis(timeoutMillis));                             SearchRequest searchRequest = new SearchRequest();                             searchRequest.source(sourceBuilder);                             // 执行检索                             return (Response) highLevelClient.search((SearchRequest) request, RequestOptions.DEFAULT);                         } catch (IOException e) {                             throw new RuntimeException(e);                         }                     }                      @Override                     public Response actionGet(long timeout, TimeUnit unit) {                         return null;                     }                      @Override                     public Response actionGet(TimeValue timeout) {                         return null;                     }                      @Override                     public boolean cancel(boolean mayInterruptIfRunning) {                         return false;                     }                      @Override                     public boolean isCancelled() {                         return false;                     }                      @Override                     public boolean isDone() {                         return false;                     }                      @Override                     public Response get() throws InterruptedException, ExecutionException {                         return null;                     }                      @Override                     public Response get(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException {                         return null;                     }                 };             } else {                 throw new UnsupportedOperationException("Unsupported action: " + action.name());             }         }          @Override         public  void execute(ActionType action, Request request, ActionListener listener) {             if (action.equals(SearchAction.INSTANCE) && request instanceof SearchRequest) {                 highLevelClient.searchAsync((SearchRequest) request, RequestOptions.DEFAULT, (ActionListener) listener);             } else {                 throw new UnsupportedOperationException("Unsupported action: " + action.name());             }         }          @Override         public ThreadPool threadPool() {             return null;         }     }; } 

以上初始化的 ElasticsearchClient 客户端中,只实现了常用的部分 actionGet 方法,其他方法在使用时再实现,实现方法基本上都差不多。

三:执行查询

ElasticsearchClient 则是可以通过 SearchRequestBuilder 来调用执行检索,在 new SearchRequestBuilder() 时,ElasticsearchClient 作为参数传递,则直接可以通过 execute().actionGet() 来执行检索并得到结果了。

public static void main(String[] args) {     RestHighLevelClient highLevelClient = getClient();     ElasticsearchClient esClient = getEsClient(highLevelClient);     SearchRequestBuilder requestBuilder = new SearchRequestBuilder(esClient, SearchAction.INSTANCE);     requestBuilder.setIndices("product_info");     requestBuilder.setFrom(0);     requestBuilder.setSize(10);     requestBuilder.setQuery(QueryBuilders.matchAllQuery());     requestBuilder.addAggregation(AggregationBuilders.terms("productName").field("productName.keyword"));     // 执行检索并获取检索结果     String s = requestBuilder.execute().actionGet().toString();     System.out.println("检索结果:" + s);     JSONObject jsonObject = JSONObject.parseObject(s);     // 获取到 agg 统计结果     JSONObject aggregations = jsonObject.getJSONObject("aggregations");     System.out.println(aggregations);     try {         highLevelClient.close();     } catch (IOException e) {         e.printStackTrace();     } } 

执行结果:

检索结果:{"took":0,"timed_out":false,"_shards":{"total":1,"successful":1,"skipped":0,"failed":0},"hits":{"total":{"value":2,"relation":"eq"},"max_score":1.0,"hits":[{"_index":"product_info","_id":"1001","_score":1.0,"_source":{"productName":"小米汽车","productDescription":"相当于保时捷特斯拉的小米超跑","color":"海蓝色","price":19}},{"_index":"product_info","_id":"1002","_score":1.0,"_source":{"productName":"小米手机","productDescription":"小米,智能手机,价格实惠便宜","color":"黑色","price":2999}}]},"aggregations":{"sterms#productName":{"doc_count_error_upper_bound":0,"sum_other_doc_count":0,"buckets":[{"key":"小米手机","doc_count":1},{"key":"小米汽车","doc_count":1}]}}} 统计结果:{"sterms#productName":{"doc_count_error_upper_bound":0,"sum_other_doc_count":0,"buckets":[{"doc_count":1,"key":"小米手机"},{"doc_count":1,"key":"小米汽车"}]}} 

相关内容

热门资讯

专业讨论!德扑之星真破解套路(... 专业讨论!德扑之星真破解套路(辅助挂)软件透明挂(有挂了解)-哔哩哔哩;人气非常高,ai更新快且高清...
每日必看!智星德州菠萝外挂检测... 每日必看!智星德州菠萝外挂检测(辅助挂)软件透明挂(有挂教学)-哔哩哔哩1、玩家可以在智星德州菠萝外...
透视透明挂!轰趴十三水有后台(... 轰趴十三水有后台赢率提升策略‌;透视透明挂!轰趴十三水有后台(辅助挂)软件透明挂(有挂详情)-哔哩哔...
发现玩家!德扑ai助手软件(辅... 发现玩家!德扑ai助手软件(辅助挂)透视辅助(有挂教学)-哔哩哔哩;玩家在德扑ai助手软件中需先进行...
一分钟了解!x-poker辅助... 一分钟了解!x-poker辅助软件(辅助挂)辅助透视(有挂攻略)-哔哩哔哩1、每一步都需要思考,不同...
一分钟揭秘!德州最新辅助器(辅... 一分钟揭秘!德州最新辅助器(辅助挂)透视辅助(有挂攻略)-哔哩哔哩;德州最新辅助器最新版本免费下载安...
玩家攻略推荐!德州辅助(辅助挂... 玩家攻略推荐!德州辅助(辅助挂)辅助透视(有挂了解)-哔哩哔哩是由北京得德州辅助黑科技有限公司精心研...
揭秘真相!pokernow德州... 《揭秘真相!pokernow德州(辅助挂)辅助透视(有挂介绍)-哔哩哔哩》 pokernow德州软件...
五分钟了解!德州之星辅助器(辅... 五分钟了解!德州之星辅助器(辅助挂)辅助透视(有挂透明)-哔哩哔哩1、很好的工具软件,可以解锁游戏的...
推荐一款!pokermaste... 1、推荐一款!pokermaster有外挂(辅助挂)透视辅助(有挂教学)-哔哩哔哩;详细教程。2、p...