Elasticsearch8.x版本Java客户端Elasticsearch Java API Client中常用API练习

import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestClientBuilder;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.SearchHit;
 
public class ElasticsearchAPIExercize {
    public static void main(String[] args) throws IOException {
        // 初始化Elasticsearch客户端
        RestClientBuilder builder = RestClient.builder(new HttpHost("localhost", 9200, "http"));
        RestHighLevelClient client = new RestHighLevelClient(builder);
 
        // 创建一个SearchRequest对象
        SearchRequest searchRequest = new SearchRequest("index_name"); // 替换为你的索引名
 
        // 构建查询条件
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        searchSourceBuilder.query(/* 构建查询 */);
        searchSourceBuilder.aggregation(/* 构建聚合 */);
        searchSourceBuilder.size(10); // 设置返回结果数量
 
        searchRequest.source(searchSourceBuilder);
 
        // 执行搜索
        SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
 
        // 处理搜索结果
        for (SearchHit hit : searchResponse.getHits().getHits()) {
            System.out.println(hit.getSourceAsString());
        }
 
        // 关闭客户端
        client.close();
    }
}

这个代码示例展示了如何在Elasticsearch 8.x版本中使用Java API Client进行基本的搜索操作。你需要替换index_name为你的目标索引名，并且提供具体的查询条件。这个简单的例子演示了如何构建一个搜索请求，如何执行这个请求，并处理返回的结果。在实际应用中，你需要根据具体的查询需求来构建查询条件。