Java Elasticsearch 时间范围查询和倒序排序工具类

以下是一个Java工具类，可用于查询Elasticsearch数据，支持时间范围查询并按时间倒序排序：

import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.sort.SortBuilders;
import org.elasticsearch.search.sort.SortOrder;

import java.io.IOException;
import java.util.Date;

public class ElasticsearchQueryUtils {

    private RestHighLevelClient client;

    public ElasticsearchQueryUtils(RestHighLevelClient client) {
        this.client = client;
    }

    public SearchResponse searchByTimeRange(String indexName, String timeField, Date startTime, Date endTime, int from, int size) throws IOException {
        SearchRequest searchRequest = new SearchRequest(indexName);
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        searchSourceBuilder.query(QueryBuilders.rangeQuery(timeField).gte(startTime).lte(endTime));
        searchSourceBuilder.sort(SortBuilders.fieldSort(timeField).order(SortOrder.DESC));
        searchSourceBuilder.from(from);
        searchSourceBuilder.size(size);
        searchSourceBuilder.timeout(TimeValue.timeValueSeconds(60));
        searchRequest.source(searchSourceBuilder);
        SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
        return searchResponse;
    }
}

其中，'client' 参数是 Elasticsearch 的 RestHighLevelClient 客户端。'searchByTimeRange' 方法接收以下参数：

• 'indexName'：要查询的索引名称；
• 'timeField'：存储时间信息的字段名称；
• 'startTime'：查询的开始时间；
• 'endTime'：查询的结束时间；
• 'from'：查询结果的起始位置；
• 'size'：查询结果的数量限制；

该方法会返回一个 'SearchResponse' 对象，其中包含了查询结果。可以根据需要对查询结果进行处理。