To show every urls of all images from a source code (html) file.

ImageFileUrlPrinter.java

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;

public class ImageFileUrlPrinter {

    private static final String USER_ID = "999999"; // Target userID
    private static final String CONDITION = "\" src=\"https://fanty-master-storage.s3.ap-northeast-1.amazonaws.com/user/" + USER_ID + "/post/";

    public static void main(String[] args) {
        // candfans.html is a html source code that you saved from a fully-generageted html of the target user's page.
        File file = new File("candfans.html");
        FileReader reader = null;
        try {
            reader = new FileReader(file);
            BufferedReader br = new BufferedReader(reader);
            for (String line = br.readLine(); line != null; line = br.readLine()) {
                int start = 0;
                int end = 0;
                int jpeg = 0;
                int jpg = 0;
                int png = 0;

                start = line.indexOf(CONDITION, start);
                while (start >= 0) {
                    jpeg = line.indexOf(".jpeg", start);
                    if (jpeg > 0 && jpeg - start < 150) {
                        start = start + 7;
                        end = jpeg + 5;
                        System.out.println(line.substring(start, end));
                    }
                    jpg = line.indexOf(".jpg", start);
                    if (jpg > 0 && jpg - start < 150) {
                        start = start + 7;
                        end = jpg + 4;
                        System.out.println(line.substring(start, end));
                    }
                    png = line.indexOf(".png", start);
                    if (png > 0 && png - start < 150) {
                        start = start + 7;
                        end = png + 4;
                        System.out.println(line.substring(start, end));
                    }
                    start = end;

                    start = line.indexOf(CONDITION, start);
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (reader != null) {
                    reader.close();
                }
            } catch (Exception e) {
                // do nothing
            }
        }
    }
}