How do I use Twitter4J to retrieve images in tweets?

Question

I want to issue a query of a keyword or hashtag and retrieve all the images from all the tweets that contain the keyword. I can use Twitter4J with Java to easily issue a query and retrieve the resulting tweets. I know that the http://t.co/xxxx links I can visit in my browser and see the associated image. That image is at https://pbs.twimg.com/xxxxx. So seems like all I have to do is that process in my code!

I can parse the http://t.co/xxxx link in each tweet easily enough. However, when I retrieve all the html from that link, I don't see any https://pbs.twimg.com/xxxx images :(. I think what's happening is twitter is loading those images through JavaScript.

Is there any way I can easily retrieve the images on each tweet??

This is what I have so far:

package com.company;

import twitter4j.*;
import twitter4j.conf.ConfigurationBuilder;

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

public class Main {

    public static void main(String[] args) throws Exception {
        ConfigurationBuilder cb = new ConfigurationBuilder();
        cb.setDebugEnabled(true)
                .setOAuthConsumerKey("xxxxxxxxxx")
                .setOAuthConsumerSecret("xxxxxxxxxxxx")
                .setOAuthAccessToken("xxxxxxxxx-xxx-xxxxxxxx")
                .setOAuthAccessTokenSecret("xxxxxxxxxxxxxxxxxxx");
        TwitterFactory tf = new TwitterFactory(cb.build());
        Twitter twitter = tf.getInstance();
        Query query = new Query("#hashtag");
        QueryResult result = twitter.search(query);
        Pattern pattern = Pattern.compile("http://t.co/\\w{10}");
        Pattern imagePattern = Pattern.compile("https\\:\\/\\/pbs\\.twimg\\.com/media/\\w+\\.(png | jpg | gif)(:large)?");
        for (Status status : result.getTweets()) {
            if (status.isRetweet())
                continue;
            System.out.println("@" + status.getUser().getScreenName() + ":" + status.getText());
            Matcher matcher = pattern.matcher(status.getText());

                if (matcher.find()) {
                    System.out.println("found a t.co url");
                    URL oracle = new URL(matcher.group());
                    BufferedReader in = new BufferedReader(
                            new InputStreamReader(oracle.openStream()));

                    String inputLine;
                    while ((inputLine = in.readLine()) != null) {
                        matcher = imagePattern.matcher(inputLine);

                        if (matcher.find())
                            System.out.println("YAYAAYAYAYYAYAYAYAYAYAYAYAYAAYAYYAYAAYYAYAYAYA: " + matcher.group());
                    }

                    in.close();

            }

        }
    }
}

Answer 1

to download all medias in the twitter4J Status

for (MediaEntity m : medias) {
            try {
                URL url = new URL(m.getMediaURL());
                InputStream in = new BufferedInputStream(url.openStream());
                ByteArrayOutputStream out = new ByteArrayOutputStream();
                byte[] buf = new byte[1024];
                int n = 0;
                while (-1 != (n = in.read(buf))) {
                    out.write(buf, 0, n);
                }
                out.close();
                in.close();
                byte[] response = out.toByteArray();
                FileOutputStream fos = new FileOutputStream(file.getAbsolutePath() + "\\" + m.getId() + "." + getExtension(m.getType()));
                fos.write(response);
                fos.close();
            } catch (Exception ex) {
                ex.printStackTrace();
            }
        }

to get the file extension

private String getExtension(String type) {
        if (type.equals("photo")) {
            return "jpg";
        } else if (type.equals("video")) {
            return "mp4";
        } else if (type.equals("animated_gif")) {
            return "gif";
        } else {
            return "err";
        }
    }

Answer 2

There is a simpler way to retrieve images in tweets.
If a tweet has an image inserted you can use getMediaEntities() to get the data of the media, and then retrieve the url with getMediaURL()
You should do something like this

MediaEntity[] media = status.getMediaEntities(); //get the media entities from the status
for(MediaEntity m : media){ //search trough your entities
    System.out.println(m.getMediaURL()); //get your url!
}