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：

1. 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>

2. 创建Elasticsearch REST客户端实例：

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

3. 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);

4. 处理查询结果：

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

使用Elasticsearch高级客户端：

1. 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>

2. 创建Elasticsearch高级客户端实例：

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

3. 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);

4. 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。