java怎么查询es数据

要查询Elasticsearch（ES）数据，您可以使用Java的Elasticsearch REST客户端或Java的Elasticsearch高级客户端。

使用Elasticsearch REST客户端：

添加Elasticsearch REST客户端的依赖。例如，使用Maven添加以下依赖：

<dependency><groupId>org.elasticsearch.client</groupId><artifactId>elasticsearch-rest-client</artifactId><version>7.12.1</version></dependency>

创建Elasticsearch REST客户端实例：

RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200, "http")).build();

创建一个搜索请求并执行查询：

Request request = new Request("GET", "/your-index/_search");request.setJsonEntity("{\"query\": {\"match_all\": {}}}");Response response = restClient.performRequest(request);

处理查询结果：

String responseBody = EntityUtils.toString(response.getEntity());System.out.println(responseBody);

使用Elasticsearch高级客户端：

添加Elasticsearch高级客户端的依赖。例如，使用Maven添加以下依赖：

<dependency><groupId>org.elasticsearch.client</groupId><artifactId>elasticsearch-rest-high-level-client</artifactId><version>7.12.1</version></dependency>

创建Elasticsearch高级客户端实例：

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

创建一个搜索请求并执行查询：

SearchRequest searchRequest = new SearchRequest("your-index");SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();searchSourceBuilder.query(QueryBuilders.matchAllQuery());searchRequest.source(searchSourceBuilder);SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);

处理查询结果：

SearchHit[] hits = searchResponse.getHits().getHits();for (SearchHit hit : hits) {String sourceAsString = hit.getSourceAsString();System.out.println(sourceAsString);}

这是查询ES数据的基本示例。您可以根据自己的需求进行进一步的查询和结果处理。