AggregationBuilders.max

创建Test20_Doc_Agg_Max

package com.stt.demo;

import org.apache.http.HttpHost;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.search.aggregations.Aggregation;
import org.elasticsearch.search.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.metrics.ParsedMax;
import org.elasticsearch.search.builder.SearchSourceBuilder;

import java.io.IOException;

public class Test20_Doc_Agg_Max {
    public static void main(String[] args) throws IOException {
        // 创建客户端
        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(new HttpHost("localhost", 9200, "http"))
        );

        // 创建查询请求对象
        SearchRequest request = new SearchRequest();
        request.indices("student");

        // 构建查询请求体
        SearchSourceBuilder builder = new SearchSourceBuilder()
                .aggregation(AggregationBuilders.max("max_age").field("age"));

        builder.size(0);
        request.source(builder);

        SearchResponse response = client.search(request, RequestOptions.DEFAULT);

        // 查询后匹配
        System.out.println("took:" + response.getTook());
        System.out.println("time out:" + response.isTimedOut());

        for (Aggregation agg : response.getAggregations()) {
            System.out.println(agg.getName());
            System.out.println(((ParsedMax) agg).getValue());
        }

        // 关闭客户端
        client.close();
    }
}

返回

took:2ms
time out:false
max_age
50.0