SpringBoot整合Elasticsearch游标查询的示例代码（scroll）

GET /old_index/_search?scroll=1m 
{
  "query": { "match_all": {}},
  "sort" : ["_doc"], 
  "size": 1000
}

{
  "_scroll_id": "cXVlcnlUaGVuRmV0Y2g7NTsxMDk5NDpkUmpiR2FjOFNhNnlCM1ZDMWpWYnRROzEwOTk1OmRSamJHYWM4U2E2eUIzVkMxalZidFE7MTA5OTM6ZFJqYkdhYzhTYTZ5QjNWQzFqVmJ0UTsxMTE5MDpBVUtwN2lxc1FLZV8yRGVjWlI2QUVBOzEwOTk2OmRSamJHYWM4U2E2eUIzVkMxalZidFE7MDs=",
  "took": 10,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "failed": 0
  },
  "hits": {
    "total": 2633253,
    "max_score": 1.0,
    "hits": [
      {
        "_index": "old_index",
        "_type": "old_index_type",
        "_id": "1",
        "_score": 1.0,
        "_source": {
          ...
        }
      }
    ]
  }
}

GET /_search/scroll
{
  "scroll": "1m", 
  "scroll_id" : "cXVlcnlUaGVuRmV0Y2g7NTsxMDk5NDpkUmpiR2FjOFNhNnlCM1ZDMWpWYnRROzEwOTk1OmRSamJHYWM4U2E2eUIzVkMxalZidFE7MTA5OTM6ZFJqYkdhYzhTYTZ5QjNWQzFqVmJ0UTsxMTE5MDpBVUtwN2lxc1FLZV8yRGVjWlI2QUVBOzEwOTk2OmRSamJHYWM4U2E2eUIzVkMxalZidFE7MDs="
}

/**
 * 游标查询
 * @param params 查询入参
 * @param indexName 索引名称
 * @param type 索引类型
 * @param defaultSort 默认排序
 * @param keyMappings 字段映射
 * @param keyMappingsMap 索引对应字段映射
 * @param scrollTimeInMillis 游标开启的时间
 * @return Page
 */
protected Page<Map> commonStartScroll(Map<String, String> params, String indexName, String type, String defaultSort,
                 Map<Key, FieldDefinition> keyMappings,
                 Map<String, Map<Key, FieldDefinition>> keyMappingsMap, long scrollTimeInMillis) {
  SearchQuery searchQuery = buildSearchQuery(params, indexName, type, defaultSort, keyMappings, keyMappingsMap);
  return elasticsearchTemplate.startScroll(scrollTimeInMillis, searchQuery, Map.class);
}

/**
 * 游标查询
 * @param scrollId 游标ID
 * @param scrollTimeInMillis 游标开启的时间
 * @return Page
 */
protected Page<Map> commonContinueScroll(String scrollId, long scrollTimeInMillis) {
  return elasticsearchTemplate.continueScroll(scrollId, scrollTimeInMillis, Map.class);
}

/**
 * 根据游标ID清除游标（提早释放资源，降低ES的负担）
 * @param scrollId 游标ID
 */
protected void clearScroll(String scrollId) {
  elasticsearchTemplate.clearScroll(scrollId);
}

/**
 * 游标查询
 * @param params 查询条件
 * @return page
 */
public Page<Map> scroll(Map<String, String> params) {
  IndexConfig config = indexEntity.getConfigByDocCode(DOC_CODE);

  // 如果请求参数包含游标ID，则说明执行翻页操作，否则认为开启新的游标查询
  String scrollId = params.getOrDefault(SCROLL_ID, null);
  if (StringUtils.isNotBlank(scrollId)) {
    return commonContinueScroll(params.get(scrollId), config.getScrollTimeInMillis());
  }
  return commonStartScroll(params, config.getIndexName(), config.getType(), DEFAULT_SORT,
      keyMappings, keyMappingsMap, config.getScrollTimeInMillis());
}
public void clearScroll(String scrollId) {
  super.clearScroll(scrollId);
}

@PostMapping("/scroll")
public ResponseResult scroll(@RequestBody Map<String, String> params) {

  return ResponseResult.success(storeSearchService.scroll(params));
}

@GetMapping("/scroll/clear/{scrollId}")
public ResponseResult clearScroll(@PathVariable String scrollId) {
  storeSearchService.clearScroll(scrollId);
  return ResponseResult.success(null);
}