How to remove items from an ArrayList, which are stored in a external txt file

Question

I wanted to know how I can remove items in an ArrayList, which are stored in an external text file. I am trying the Iterator method but I do not think I am doing it correctly.

This is the arraylist, which basically contains the text file of responses

This is the method, which allowed a txt file to hold an ArrayList of responses

public void writeAList(ArrayList<String> list, String filename)
    {
        if(list != null) {
            try (FileWriter writer = new FileWriter(filename, true)) {
                for(String item : list) {
                    writer.write(item.trim());
                    writer.write(" ");
                }       
                writer.write("\n");
            }
            catch(IOException e) {
                System.out.println("Problem writing file: " + filename +
                                   " in writeAList");
            }

        }
        else {
            System.out.println("Null list passed to writeAList.");
        }
    }

This is the method that allows to read from it

public ArrayList<String> readAList(String filename)
{
    ArrayList<String> list = new ArrayList<>();
    try (BufferedReader reader =
            new BufferedReader(new FileReader(filename))) {
        String line = reader.readLine();
        while(line != null) {
            list.add(line.trim());
            line = reader.readLine();
        }
    }
    catch(IOException e) {
        System.out.println("Problem reading file: " + filename +
                           " in readAList");
    }
    return list;
}

I assigned an ArrayList called like this

notRecognised = help.readAList("missed.txt");

And I tried to write the below method to be able to remove responses from the text file, but I do not think I have written it correctly.

 public String removeResponse(ArrayList<String> words)
{
    Iterator<String> it = words.iterator();
    while(it.hasNext()) {
        String word = it.next();
        String response = notRecognised.get(word);
        if(response.equals (words)) {
            it.remove();
        }
    }

}

Answer 1

Text files only store text. If you want to edit it (remove items), you have to rewrite it. A more suitable data storage for CRUD (creation, retrieval, update, delete) of data would be using a database, not a text file.

You can read up here: JDBC Database Access