es 7.x JavaAPI 文档 最大值查询 分组查询

最大值查询

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.SearchHits;
import org.elasticsearch.search.aggregations.Aggregation;
import org.elasticsearch.search.aggregations.AggregationBuilder;
import org.elasticsearch.search.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.Aggregations;
import org.elasticsearch.search.aggregations.metrics.ParsedMax;
import org.elasticsearch.search.builder.SearchSourceBuilder;

/**
 * @author:
 * 创建时间:2022/1/11 21:05
 */
public class ESTest_Doc_Query {

    public static void main(String[] args) throws Exception {
        RestHighLevelClient esClient = null;
        // 创建ES客户端
        try {
            esClient = new RestHighLevelClient(
                    RestClient.builder(new HttpHost("127.0.0.1", 9200, "http"))
            );
            SearchRequest request = new SearchRequest();
            request.indices("user");

            // 聚合查询  查最大值
            SearchSourceBuilder builder = new SearchSourceBuilder();
            AggregationBuilder aggregationBuilder = AggregationBuilders.max("maxAge").field("age");
            builder.aggregation(aggregationBuilder);

            request.source(builder);
            SearchResponse response = esClient.search(request, RequestOptions.DEFAULT);
            // 查询命中的信息
            SearchHits hits = response.getHits();

            System.out.println(hits.getTotalHits());
            System.out.println(response.getTook());
            Aggregations aggregations = response.getAggregations();
            for (Aggregation aggregation : aggregations) {
                System.out.println("aggregationName: " + aggregation.getName() + " value: " + ((ParsedMax) aggregation).value());
            }
        } finally {
            if (esClient != null) {
                // 关闭ES客户端
                esClient.close();
            }
        }
    }
}

结果如下 :

aggregationName maxAge value: 60.0

主要代码为:

AggregationBuilder aggregationBuilder = AggregationBuilders.max("maxAge").field("age");

maxAge 为自定义的聚合函数的名称. field("age") 为 要聚合操作的字段. 使用response的response.getAggregations() 获取聚合操作的结果

分组查询

对年龄进行分组操作

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.SearchHits;
import org.elasticsearch.search.aggregations.Aggregation;
import org.elasticsearch.search.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.Aggregations;
import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregationBuilder;
import org.elasticsearch.search.builder.SearchSourceBuilder;

/**
 * @author:
 * 创建时间:2022/1/11 21:05
 */
public class ESTest_Doc_Query {

    public static void main(String[] args) throws Exception {
        RestHighLevelClient esClient = null;
        // 创建ES客户端
        try {
            esClient = new RestHighLevelClient(
                    RestClient.builder(new HttpHost("127.0.0.1", 9200, "http"))
            );
            SearchRequest request = new SearchRequest();
            request.indices("user");
            // 分组查询
            SearchSourceBuilder builder = new SearchSourceBuilder();
            TermsAggregationBuilder aggregationBuilder = AggregationBuilders.terms("ageGroup").field("age");
            builder.aggregation(aggregationBuilder);

            request.source(builder);
            SearchResponse response = esClient.search(request, RequestOptions.DEFAULT);
            // 查询命中的信息
            SearchHits hits = response.getHits();

            System.out.println(hits.getTotalHits());
            System.out.println(response.getTook());
            Aggregations aggregations = response.getAggregations();
            for (Aggregation aggregation : aggregations) {
                System.out.println("aggregationName: " + aggregation.getName() + " value: " + aggregation.getType());
            }
        } finally {
            if (esClient != null) {
                // 关闭ES客户端
                esClient.close();
            }
        }
    }
}

运行结果如下图, 可以看到结果是放在aggregation的buckets中的. 分组年龄为key . 统计了数量.

主要的代码为

TermsAggregationBuilder aggregationBuilder = AggregationBuilders.terms("ageGroup").field("age");

terms("ageGroup") 为分组的名称. field("age") 为分组的字段.