Elasticsearch Java API 7.0批量插入尝试基本示例，抛出错误

import org.elasticsearch.action.bulk.BulkRequest;
import org.elasticsearch.action.bulk.BulkResponse;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.xcontent.XContentType;
import org.elasticsearch.index.Index;

import java.io.IOException;

public class ElasticsearchBulkInsertExample {
    private RestHighLevelClient client;

    public ElasticsearchBulkInsertExample() {
        // 初始化Elasticsearch客户端
        client = new RestHighLevelClient(/* 初始化配置 */);
    }

    public void bulkInsert() {
        BulkRequest bulkRequest = new BulkRequest();

        // 构建多个IndexRequest
        IndexRequest request1 = new IndexRequest("index_name").id("1").source(/* 文档内容 */, XContentType.JSON);
        IndexRequest request2 = new IndexRequest("index_name").id("2").source(/* 文档内容 */, XContentType.JSON);
        // 添加到BulkRequest中
        bulkRequest.add(request1);
        bulkRequest.add(request2);

        try {
            // 执行批量插入
            BulkResponse bulkResponse = client.bulk(bulkRequest, RequestOptions.DEFAULT);

            if (bulkResponse.hasFailures()) {
                // 处理错误
                System.out.println("批量插入过程中出现错误：" + bulkResponse.buildFailureMessage());
            } else {
                // 处理成功
                System.out.println("批量插入成功！");
            }
        } catch (IOException e) {
            // 处理异常
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        ElasticsearchBulkInsertExample example = new ElasticsearchBulkInsertExample();
        example.bulkInsert();
    }
}