数据量小的方法一：

首先必须创建client

public class ClientConfig {
          
   
    /**
     * 批量导入到es中必须的
     * @return  RestHighLevelClient
     */
    @Bean
    public RestHighLevelClient restHighLevelClient(){
          
   
        return new RestHighLevelClient(RestClient.builder(
                HttpHost.create("http://192.168.150.102:9200")
        ));
    }
}

批量导入数据量大时，用分页

public class FeignTest {
          
   

    @Autowired
    private ItemMapperService itemService;
    @Autowired
    private RestHighLevelClient client;
    /**
     * 批量导入文档  方式一
     */
    @Test
    void testBulkRequest() throws IOException {
          
   
        buildPage(0, 20000);
    }

    private void buildPage(int current, int size) throws IOException {
          
   
        //构建分页器
        List<Item> records = itemService.page(new Page<>(current, size)).getRecords();
        //判断
        if (records == null||records.size() == 0) {
          
   
            return;
        }
        //转换为文档类型
        // 1.创建Request
        BulkRequest request = new BulkRequest();
        // 2.准备参数，添加多个新增的Request
        for (Item list : records) {
          
   
            // 2.1.转换为文档类型HotelDoc
            ItemDoc itemDoc= new ItemDoc(list);
            //创建新增文档的request对象
            request.add(new IndexRequest("item")
                    .id(itemDoc.getId().toString())
                    .source(JSON.toJSONString(itemDoc), XContentType.JSON));
        }
        // 3.发送请求
        client.bulk(request, RequestOptions.DEFAULT);
        buildPage(current + 1, size);
    }
}

Json的依赖

<dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.78</version>
        </dependency>