search_after.java

package javahighclient.searchafter;

import java.io.IOException;
import java.util.Arrays;
import java.util.Objects;
import java.util.stream.Collectors;
import javahighclient.RestClientUtils;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.sort.SortBuilders;
import org.elasticsearch.search.sort.SortOrder;

public class Main {

  public static void main(String[] args) throws IOException {
    var client = RestClientUtils.getClient();

    SearchSourceBuilder builder = getSearchSourceBuilder(null);

    SearchResponse response = getSearchResponse(client, builder);

    Arrays.stream(response.getHits().getHits()).forEach(
        h -> System.out.println(h.getSourceAsString())
    );

    System.out.println(">>>>>> Next PAGE");
    
    var lastDoc = Arrays.stream(response.getHits().getHits()).collect(Collectors.toList()).get(response.getHits().getHits().length - 1);

    builder = getSearchSourceBuilder(new Object[]{lastDoc.getScore(), lastDoc.getSourceAsMap().get("code")});

    response = getSearchResponse(client, builder);

    Arrays.stream(response.getHits().getHits()).forEach(
        h -> System.out.println(h.getSourceAsString())
    );

  }

  private static SearchResponse getSearchResponse(org.elasticsearch.client.RestHighLevelClient client, SearchSourceBuilder builder)
      throws IOException {
    SearchRequest searchRequest = new SearchRequest();
    searchRequest.indices("idx_movies_suggest");
    searchRequest.source(builder);
    return client.search(searchRequest, RequestOptions.DEFAULT);
  }

  private static SearchSourceBuilder getSearchSourceBuilder(Object[] arrSearchAfter) {
    SearchSourceBuilder builder = new SearchSourceBuilder();
    builder.sort(SortBuilders.fieldSort("_score").order(SortOrder.DESC));
    builder.sort(SortBuilders.fieldSort("code").order(SortOrder.ASC));
    builder.size(5);
    builder.query(QueryBuilders.matchAllQuery());
    if (Objects.nonNull(arrSearchAfter)) {
      builder.searchAfter(arrSearchAfter);
    }
    return builder;
  }
}