java - Youtube 搜索 :list getting PageInfo and nextPageToken null

Question

我正在尝试使用关键字从 YouTube 获取视频。我正在使用 YouTube API Java 库。我可以成功获取前 50 条记录，但要获取下一条记录，需要设置 nextPageToken。但我得到 nextPageToken null。下面是我的代码。

YouTube.Search.List search = youtube.search().list("id,snippet");
search.setOauthToken(credential.getAccessToken());
search.setMaxResults(50L);
search.setQ(keywords); // keywords is string type and input by user.
search.setType("video");
search.setFields("items(id/kind,id/videoId,snippet/title,snippet/thumbnails/default/url)");

VideoList returnList = new VideoList();

    do {

        search.setKey("MYKEY");
        SearchListResponse searchResponse = search.execute();
        // This get 50 items proper.
        List<SearchResult> searchResultList = searchResponse.getItems();


        // Why PageInfo is null? 
        PageInfo pageInfo = searchResponse.getPageInfo();

        // int totalResults = pageInfo.getTotalResults();
        // int pageSize = pageInfo.getResultsPerPage();

        if(searchResponse != null){
            // i use searchResultList and update my database for search.
            ....
            ....

            // PageToken also null.
            String pageToken  = searchResponse.getNextPageToken();
            search.setPageToken(pageToken);
        }
        else{
            break;
        }
    } while (true);
    }catch(Exception ex){
        ex.printStackTrace();
    }

Answer 1

你得到的是 null 因为你没有提到 nextpagetoken 或 pageinfo 字段，当您明确设置字段时，搜索结果集是有限的。

search.setFields("items(kind,id/kind,id/videoId,snippet/title,snippet/thumbnails/default/url),nextPageToken,pageInfo,prevPageToken");

System.out.println("PAGE INFO: " +response.getPageInfo());

System.out.println("next page token :" +response.getNextPageToken());

System.out.println("prev page token:"+ response.getPrevPageToken());

输出:输入搜索词

扑克脸

页面信息:{"resultsPerPage":2,"totalResults":667891}

下一页 token :CAIQAA

上一页token:null