OpenSearch:Démonstration de requête itérative par défilement

Configurer les identifiants

Stockez votre paire AccessKey dans des variables d'environnement. Ne codez pas vos identifiants en dur dans le code source.

Linux et macOS

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

Remplacez <access_key_id> et <access_key_secret> par l'ID AccessKey et le secret AccessKey de votre utilisateur RAM.

Windows

1. Créez un fichier de variables d'environnement et ajoutez les variables ALIBABA_CLOUD_ACCESS_KEY_ID et ALIBABA_CLOUD_ACCESS_KEY_SECRET avec votre ID AccessKey et votre secret AccessKey.

2. Redémarrez Windows pour que les modifications prennent effet.

package com.aliyun.opensearch;

import com.aliyun.opensearch.sdk.dependencies.com.google.common.collect.Lists;
import com.aliyun.opensearch.sdk.generated.OpenSearch;
import com.aliyun.opensearch.sdk.generated.search.*;
import com.aliyun.opensearch.search.DeepPageingIterator;
import java.nio.charset.Charset;

public class testScrollIterator {

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

    public static void main(String[] args) {

        // Read credentials from environment variables.
        // Set the environment variables before running this example.
        String accesskey = System.getenv("ALIBABA_CLOUD_ACCESS_KEY_ID");
        String secret = System.getenv("ALIBABA_CLOUD_ACCESS_KEY_SECRET");

        // Print the file encoding and default charset for debugging.
        System.out.println(String.format("file.encoding: %s", System.getProperty("file.encoding")));
        System.out.println(String.format("defaultCharset: %s", Charset.defaultCharset().name()));

        // Build the client chain: OpenSearch -> OpenSearchClient -> SearcherClient.
        OpenSearch openSearch = new OpenSearch(accesskey, secret, host);
        OpenSearchClient serviceClient = new OpenSearchClient(openSearch);
        SearcherClient searcherClient = new SearcherClient(serviceClient);

        // Configure the query: application name, hits per page, return fields, and data format.
        Config config = new Config(Lists.newArrayList(appName));
        // The start parameter has no effect on scroll queries; default value 0 is used.
        config.setStart(start);
        // Return 5 documents per page.
        config.setHits(5);
        // Supported formats: JSON and FULLJSON.
        config.setSearchFormat(SearchFormat.FULLJSON);
        config.setFetchFields(Lists.newArrayList("id", "name", "phone", "int_arr", "literal_arr", "float_arr", "cate_id"));
        // Note: Set the rerank_size parameter via the setReRankSize method of the Rank class.

        // Define the query, filter, and sort conditions.
        SearchParams searchParams = new SearchParams(config);
        // To search across multiple index fields, specify all fields in one setQuery call.
        // Multiple setQuery calls overwrite each other; only the last one takes effect.
        searchParams.setQuery("name:'opensearch'");
        searchParams.setFilter("cate_id<=3");

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

        // Attach a DeepPaging object to enable scroll queries.
        DeepPaging deep = new DeepPaging();
        searchParams.setDeepPaging(deep);

        // Create the iterator. It manages scroll IDs automatically.
        DeepPageingIterator pagesIterator = new DeepPageingIterator(searcherClient, searchParams);
        // Set the interval between page fetches, in milliseconds.
        // The default is 100 ms. Adjust based on your throughput needs.
        pagesIterator.setPagingIntervals(80);

        // Iterate through all pages.
        // Check error codes and messages to detect failures, not the status field.
        try {
            System.out.println("test");
            while (pagesIterator.hasNext()) {
                System.out.println("Debugging information:" + pagesIterator.next());
            }
        } catch (Exception ex) {
            System.out.println("Error message:" + ex.getMessage());
        }
    }
}