ES使用游标查询数据

// 统计查询
CountRequest countRequest = new CountRequest();
countRequest.types("类型，按照版本进行使用");
countRequest.indices("索引");
// 构建查询参数
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
// 设置统计查询参数
countRequest.source(searchSourceBuilder);
// 统计数量
CountResponse countResponse = restHighLevelClient.count(countRequest,RequestOptions.DEFAULT);
// 获取数量
long count = countResponse.getCount();
if(count > 500000){
    throw new RumtimeException("下载数量不允许超过50W");
}
// 数量大于1W条时使用scroll进行下载数据
if (count > 10000) {
    searchSourceBuilder.size(10000);
    SearchRequest searchRequest = new SearchRequest("索引").types("类型，按版本判断是否使用");
    searchRequest.source(searchSourceBuilder);
    // 创建游标并设置过期时间
    Scroll scroll = new Scroll(TimeValue.timeValueMinutes(5L));
    // 设定游标
    searchRequest.scroll(scroll);
    // 执行查询，获取响应数据和游标ID
    SearchResponse searchResponse = restHighLevelClient.search(request, RequestOptions.DEFAULT);
    String scrollId = searchResponse.getScrollId();
    SearchHit[] searchHits = searchResponse.getHits().getHits();
    // 收集数据集合
    List searchHitList = new ArrayList<>(Arrays.asList(searchHits));
    while (true) {
        if (searchHits.length == 0) {
            break;
        }
        // 创建游标查询请求
        SearchScrollRequest scrollRequest = new SearchScrollRequest(scrollId);
        // 设定游标时长
        scrollRequest.scroll(scroll);
        // 使用游标进行查询
        searchResponse = restHighLevelClient.scroll(searchScrollRequest, RequestOptions.DEFAULT);
        // 获取游标ID
        scrollId = searchResponse.getScrollId();
        // 获取数据
        searchHits = searchResponse.getHits().getHits();
        searchHitList.addAll(Arrays.asList(searchHits));
    }
    // 清除游标ID
    ClearScrollRequest clearScrollRequest = new ClearScrollRequest();
    clearScrollRequest.addScrollId(scrollId);
    restHighLevelClient.clearScroll(clearScrollRequest,RequestOptions.DEFAULT);
    // TODO process 处理逻辑
    return;  
}