OpenSearch:Demostración de consulta iterativa scroll

Configurar las credenciales

Almacene su par de AccessKey como variables de entorno. No codifique las credenciales directamente en el código fuente.

Linux y macOS

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

Reemplace <access_key_id> y <access_key_secret> con el ID de AccessKey y el secreto de AccessKey de su usuario de RAM.

Windows

1. Cree un archivo de variables de entorno y agregue ALIBABA_CLOUD_ACCESS_KEY_ID y ALIBABA_CLOUD_ACCESS_KEY_SECRET con su ID de AccessKey y su secreto de AccessKey.

2. Reinicie Windows para que los cambios surtan efecto.

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());
        }
    }
}