elasticsearch 分页可以任意跳转到某一页当超过10000条怎么解决给出具体java代码示例

当超过10000条时，可以使用scroll API进行分页查询，具体的Java代码示例如下：

import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.Client;
import org.elasticsearch.index.query.QueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.sort.SortOrder;

import java.util.ArrayList;
import java.util.List;

public class ElasticsearchUtil {

    private static final int PAGE_SIZE = 1000;

    /**
     * 普通分页查询
     *
     * @param client
     * @param index
     * @param type
     * @param queryBuilder
     * @param pageNum
     * @return
     */
    public static List<Object> searchPage(Client client, String index, String type, QueryBuilder queryBuilder, int pageNum) {
        int from = (pageNum - 1) * PAGE_SIZE;
        SearchResponse searchResponse = client.prepareSearch(index)
                .setTypes(type)
                .setQuery(queryBuilder)
                .setFrom(from)
                .setSize(PAGE_SIZE)
                .addSort("_id", SortOrder.ASC)
                .execute()
                .actionGet();

        SearchHits hits = searchResponse.getHits();
        List<Object> list = new ArrayList<>();
        for (SearchHit hit : hits) {
            Object obj = hit.getSourceAsString();
            list.add(obj);
        }

        return list;
    }

    /**
     * 使用scroll API进行分页查询
     *
     * @param client
     * @param index
     * @param type
     * @param queryBuilder
     * @param pageNum
     * @return
     */
    public static List<Object> searchScroll(Client client, String index, String type, QueryBuilder queryBuilder, int pageNum) {
        String scrollId = null;
        List<Object> list = new ArrayList<>();
        try {
            SearchResponse searchResponse = client.prepareSearch(index)
                    .setTypes(type)
                    .setQuery(queryBuilder)
                    .setSize(PAGE_SIZE)
                    .addSort("_id", SortOrder.ASC)
                    .setScroll("1m")
                    .execute()
                    .actionGet();
            scrollId = searchResponse.getScrollId();

            while (true) {
                SearchHits hits = searchResponse.getHits();
                for (SearchHit hit : hits) {
                    Object obj = hit.getSourceAsString();
                    list.add(obj);
                }

                searchResponse = client.prepareSearchScroll(scrollId)
                        .setScroll("1m")
                        .execute()
                        .actionGet();
                if (searchResponse.getHits().getHits().length == 0) {
                    break;
                }
            }
        } finally {
            if (scrollId != null) {
                client.prepareClearScroll().addScrollId(scrollId).execute().actionGet();
            }
        }

        int from = (pageNum - 1) * PAGE_SIZE;
        int to = from + PAGE_SIZE;
        if (to > list.size()) {
            to = list.size();
        }

        return list.subList(from, to);
    }
}

其中，普通分页查询使用了Elasticsearch的from和size参数进行分页查询，但是当数据量很大时，这种方式会非常慢。因此，我们使用了scroll API进行分页查询，它可以通过游标的方式进行查询，性能更高。具体使用方法是，首先使用prepareSearch方法进行查询，设置scroll参数，获取第一批数据和scrollId，然后使用prepareSearchScroll方法进行下一批数据的查询，直到没有数据为止。最后将查询结果进行分页返回即可