java如何查询es数据

要查询Elasticsearch（ES）数据，您可使用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客户真个依赖。例如，使用Maven添加以下依赖：
```xml

org.elasticsearch.client
elasticsearch-rest-client
7.12.1

```
2. 创建Elasticsearch REST客户端实例：
```java
RestClient restClient = RestClient.builder(
new HttpHost("localhost", 9200, "http")).build();
```
3. 创建一个搜索要求并履行查询：
```java
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：
```java
String responseBody = EntityUtils.toString(response.getEntity());
System.out.println(responseBody);
```
使用Elasticsearch高级客户端：
1. 添加Elasticsearch高级客户真个依赖。例如，使用Maven添加以下依赖：
```xml

org.elasticsearch.client
elasticsearch-rest-high-level-client
7.12.1

```
2. 创建Elasticsearch高级客户端实例：
```java
RestHighLevelClient client = new RestHighLevelClient(
RestClient.builder(new HttpHost("localhost", 9200, "http")));
```
3. 创建一个搜索要求并履行查询：
```java
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：
```java
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。