OpenSearch:Exemple de requête par défilement

export ALIBABA_CLOUD_ACCESS_KEY_ID=<access_key_id>
export ALIBABA_CLOUD_ACCESS_KEY_SECRET=<access_key_secret>

package com.aliyun.opensearch;

import com.aliyun.opensearch.OpenSearchClient;
import com.aliyun.opensearch.SearcherClient;
import com.aliyun.opensearch.sdk.dependencies.com.google.common.collect.Lists;
import com.aliyun.opensearch.sdk.dependencies.org.json.JSONObject;
import com.aliyun.opensearch.sdk.generated.OpenSearch;
import com.aliyun.opensearch.sdk.generated.commons.OpenSearchClientException;
import com.aliyun.opensearch.sdk.generated.commons.OpenSearchException;
import com.aliyun.opensearch.sdk.generated.search.*;
import com.aliyun.opensearch.sdk.generated.search.general.SearchResult;
import com.aliyun.opensearch.search.SearchParamsBuilder;
import java.nio.charset.Charset;

public class testScroll {

  // Scroll queries do not support the aggregate, distinct, or rank clause,
  // and support sorting by a single field only.
  private static String appName = "Name of the OpenSearch application that you want to manage";
  private static String host = "Endpoint of the OpenSearch API in your region";

  public static void main(String[] args) {
    // Read credentials from environment variables.
    // Configure the environment variables before running this code.
    String accesskey = System.getenv("ALIBABA_CLOUD_ACCESS_KEY_ID");
    String secret = System.getenv("ALIBABA_CLOUD_ACCESS_KEY_SECRET");

    System.out.println(
      String.format("file.encoding: %s", System.getProperty("file.encoding"))
    );
    System.out.println(
      String.format("defaultCharset: %s", Charset.defaultCharset().name())
    );

    // Initialize the client.
    OpenSearch openSearch = new OpenSearch(accesskey, secret, host);
    OpenSearchClient serviceClient = new OpenSearchClient(openSearch);
    SearcherClient searcherClient = new SearcherClient(serviceClient);

    // Configure the query: application name, page size, return format, and fields.
    Config config = new Config(Lists.newArrayList(appName));
    config.setStart(start); // The start parameter is ignored for scroll queries; position always starts at 0.
    config.setHits(5);      // Return 5 documents per page.
    config.setSearchFormat(SearchFormat.FULLJSON);
    config.setFetchFields(
      Lists.newArrayList("id", "name", "phone", "int_arr", "literal_arr", "float_arr", "cate_id")
    );

    SearchParams searchParams = new SearchParams(config);
    searchParams.setQuery("name:'opensearch'");
    searchParams.setFilter("cate_id<=3");

    Sort sorter = new Sort();
    sorter.addToSortFields(new SortField("id", Order.DECREASE)); // Sort by id, descending.
    searchParams.setSort(sorter);

    // Create a DeepPaging object to enable scroll queries.
    // Set the scroll ID validity period to 3 minutes (default: 1 minute).
    DeepPaging deep = new DeepPaging();
    deep.setScrollExpire("3m");
    searchParams.setDeepPaging(deep);

    SearchParamsBuilder paramsBuilder = SearchParamsBuilder.create(searchParams);

    // Step 1: Send the initial scroll query to get the first scroll ID.
    SearchResult searchResult;
    try {
      searchResult = searcherClient.execute(paramsBuilder);
      String result = searchResult.getResult();
      JSONObject obj = new JSONObject(result);

      // Step 2: Use the scroll ID from each response to fetch the next batch.
      // With 25 documents and 5 per page, the 6th iteration returns an empty result set.
      for (int i = 1; i <= 6; i++) {
        // When you run the first scroll query, a scroll ID is returned. Use this scroll ID to run the scroll query again.
        deep.setScrollId(
          new JSONObject(obj.get("result").toString())
            .get("scroll_id")
            .toString()
        );
        deep.setScrollExpire("3m"); // Reset the validity period before each request.
        searchResult = searcherClient.execute(paramsBuilder);
        result = searchResult.getResult();
        obj = new JSONObject(result);

        System.out.println("Results for Query No." + i + ": " + obj.get("result"));

        // Sleep 1 second between requests to stay within QPS limits.
        try {
          Thread.sleep(1000);
        } catch (InterruptedException e) {
          e.printStackTrace();
        }
      }
    } catch (OpenSearchException e) {
      e.printStackTrace();
    } catch (OpenSearchClientException e) {
      e.printStackTrace();
    }
  }
}