Java Web Scraping：解析动态网页内容与官方API的最佳实践

      while(in.readLine() != null) // 第一次调用readLine()，读取并消费第一行
      {
        String s = (in.readLine()); // 第二次调用readLine()，读取并消费第二行
        if(s!=null)
        {
          // ... 对第二行进行处理
        }
      }

      String line;
      while((line = in.readLine()) != null) // 在条件中读取一行并赋值给line
      {
        // 在这里处理 line 变量
        // 例如：code.add(line);
        // ...
      }

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import com.google.gson.Gson; // 假设使用Gson库解析JSON

public class YouTubeApiExample {

    private static final String API_KEY = "YOUR_API_KEY"; // 替换为您的API密钥
    private static final String VIDEO_ID = "9h5JC-GLR6g"; // YouTube视频ID

    public static void main(String[] args) {
        try {
            String apiUrl = "https://www.googleapis.com/youtube/v3/videos?part=statistics&id=" + VIDEO_ID + "&key=" + API_KEY;
            URL url = new URL(apiUrl);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("GET");

            int responseCode = connection.getResponseCode();
            if (responseCode == HttpURLConnection.HTTP_OK) {
                BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
                String inputLine;
                StringBuilder response = new StringBuilder();
                while ((inputLine = in.readLine()) != null) {
                    response.append(inputLine);
                }
                in.close();

                // 解析JSON响应
                Gson gson = new Gson();
                YouTubeApiResponse apiResponse = gson.fromJson(response.toString(), YouTubeApiResponse.class);

                if (apiResponse != null && apiResponse.getItems() != null && !apiResponse.getItems().isEmpty()) {
                    VideoItem video = apiResponse.getItems().get(0);
                    System.out.println("视频标题: " + video.getSnippet().getTitle());
                    System.out.println("播放量: " + video.getStatistics().getViewCount());
                    System.out.println("点赞数: " + video.getStatistics().getLikeCount());
                } else {
                    System.out.println("未找到视频信息或API响应异常。");
                }

            } else {
                System.out.println("API请求失败，响应码: " + responseCode);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    // 假设的YouTube API响应结构（需要根据实际API响应定义）
    // 为了简化，这里只定义了部分字段
    static class YouTubeApiResponse {
        private java.util.List<VideoItem> items;
        public java.util.List<VideoItem> getItems() { return items; }
    }

    static class VideoItem {
        private Snippet snippet;
        private Statistics statistics;
        public Snippet getSnippet() { return snippet; }
        public Statistics getStatistics() { return statistics; }
    }

    static class Snippet {
        private String title;
        public String getTitle() { return title; }
    }

    static class Statistics {
        private String viewCount;
        private String likeCount;
        // ... 其他统计数据
        public String getViewCount() { return viewCount; }
        public String getLikeCount() { return likeCount; }
    }
}