Add the time of each lesson next to the Headings of the lesson in Markdown Using Java

addTimeToHeadings.java

import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Scanner;
@SuppressWarnings("unused")
public class addTimetoHeadings {
    public static void main(String[] args)
    {
        Map<String, String> hashMap = new HashMap<String, String>();
        try {
            hashMap = readAllLines("/media/ahmed/DEV/Playling/scripts/data.txt");
            for (Map.Entry<String, String> entry : hashMap.entrySet()) {
                String key = entry.getKey();
                String value = entry.getValue();
                System.out.println("Title: " + key + ", Time: " + value);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        File markdownFile = new File("/media/ahmed/Ahmed/Important Stuff/Ahmed-Notes/Carrer/JAVA/Java Fundamentals.md");
        try {
            editFile(markdownFile, hashMap);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    public static void editFile(File file, Map<String, String> hashMap) throws IOException
    {
        // if this line contains ## + title the add the time next line
        List<String> fileContent = new ArrayList<>(Files.readAllLines(Paths.get(file.getAbsolutePath())));
        for (int i = 0; i < fileContent.size(); i++) {
            String line = fileContent.get(i);
            if (line.contains("##")) {
                String title = line.substring(3);
                String time = hashMap.get(title);
                if (time != null) {
                    fileContent.add(i + 1, time);
                }
            }
        }
        Files.write(Paths.get(file.getAbsolutePath()), fileContent);
    }

    public static Map<String, String> readAllLines(String filePath) throws FileNotFoundException, IOException
    {
        // the lins are like this
        // first line: Title
        // second line: Time
        // and so on
        File file = new File(filePath);
        BufferedReader br = new BufferedReader(new FileReader(file));
        String st;
        Map<String, String> hashMap = new HashMap<String, String>();
        int i = 0;
        String title = null, time;
        while ((st = br.readLine()) != null) {
            if (i == 0) {
                title = st;
                i++;
            } else if (i == 1) {
                time = st;
                hashMap.put(title, time);
                i = 0;
            }
        }
        br.close();
        return hashMap;
    }
}