Get youtube video tags without any API in Java

I have been trying to get youtube video tags from youtube video ID, searched everywhere but got answer in PHP, I did not try anything because I am a newbie java developer.

This is a long and complicated process but I will try to explain how to do this.

1. create a url object to the video URL url = new URL(video url goes here!);
2. open a urlconnection URLConnection urlCon = url.openConnection();
3. read from the connection

InputStream inputStream = urlCon.getInputStream();
InputStreamReader reader = new InputStreamReader(inputStream);
BufferedReader br = new BufferedReader(reader);
String line = "";
while((line = br.readLine())!=null){
        //now we parse the information here!
}

4. this is the hardest part... We need to parse the information from the reader...
   I can not do this part for you because it takes a lot of time and code, but this is the fatest way to do it: go to that url and open the page's source (ctr + u), look through the source until you find the area with the tags. Now you have to parse strings over and over until you get the desired output.

After going through the source code of a youtube page, I noticed youtube tags are stored as keywords.

here how it looks like "keywords":["James","Gosling","Sun","Microsystems","Students"]

We just need to extract a string that starts with keywords and ends with ] which is followed by cleaning data

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.URL;
import java.util.Arrays;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class YoutubeTags
{
    public static void main(String[] args) {
        final String baseUrl = "https://www.youtube.com/watch?v=";
        String videoId = "r19P3y1VBiw";
        
        String tags[] = null;
        try {
            URL url = new URL(baseUrl + videoId);
            BufferedReader br = new BufferedReader(new InputStreamReader(url.openStream()));
            
            Pattern pattern = Pattern.compile("\"keywords([^\\]])*");
            String line;
            while ((line = br.readLine()) != null) {
                Matcher matcher = pattern.matcher(line);
                if (matcher.find()) {
                    tags = matcher.group().split(",");
                    break;
                }
            }
        } catch (Exception e) {
            // do something
        }

        // cleaning data
        for(int i = 0; i < tags.length; i++) {
            tags[i] = tags[i].substring(2, tags[i].length() - 2);
            if(i == 0) {
                tags[0] = tags[0].substring(tags[0].lastIndexOf("\"") + 1);
            }
        }

        System.out.println(Arrays.toString(tags));
    }
}

output


[James, Gosling, Sun, Microsystems, Students]


Note: I used this post as the base for my answer. I have removed some code for easy understanding.