es聚合分页java_ES 实现聚合分页

要实现 ES 聚合分页，可以使用 Elasticsearch 的 Java API 来编写代码。下面是一个简单的示例：

import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.common.transport.InetSocketTransportAddress;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.bucket.terms.Terms;
import org.elasticsearch.search.aggregations.metrics.sum.Sum;
import org.elasticsearch.search.sort.SortBuilders;
import org.elasticsearch.search.sort.SortOrder;
import org.elasticsearch.transport.client.PreBuiltTransportClient;

import java.net.InetAddress;
import java.util.List;
import java.util.Map;

public class AggregationPaginationExample {

    public static void main(String[] args) throws Exception {
        TransportClient client = new PreBuiltTransportClient(Settings.EMPTY)
            .addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("localhost"), 9300));

        int pageSize = 5;
        int pageNumber = 1;

        SearchResponse response = client.prepareSearch("my_index")
            .setQuery(QueryBuilders.matchAllQuery())
            .addAggregation(
                AggregationBuilders.terms("my_terms_agg")
                    .field("my_field")
                    .subAggregation(AggregationBuilders.sum("my_sum_agg").field("my_other_field"))
                    .order(Terms.Order.aggregation("my_sum_agg", false))
                    .size(pageSize)
                    .from((pageNumber - 1) * pageSize)
            )
            .setSize(0)
            .get();

        Terms termsAgg = response.getAggregations().get("my_terms_agg");
        for (Terms.Bucket bucket : termsAgg.getBuckets()) {
            String key = bucket.getKeyAsString();
            long docCount = bucket.getDocCount();
            Sum sumAgg = bucket.getAggregations().get("my_sum_agg");
            double sumValue = sumAgg.getValue();

            System.out.println(key + ": " + docCount + " documents, sum = " + sumValue);
        }

        client.close();
    }
}

这个示例使用了 Elasticsearch 的 Java API，查询一个名为 `my_index` 的索引，按照 `my_field` 字段进行分组，并计算每组中 `my_other_field` 字段的总和。然后按照总和排序，并使用分页参数进行分页。最后打印出每个分组的结果。

需要注意的是，聚合分页的实现方式与普通的分页略有不同，具体可以参考上面的代码示例。