save changes (permanently) in an arraylist?

Question

Is that possible? Like for example, a user added a new item/element into the arraylist (bufferedreader process) and surely, there would be changes happen. My question is that is

Answer 1

If I understand you aren't allowed to use a text file to store your data in CSV format, maybe Serialization/Deserialization is what you, or your teacher ;-), want or wants you to do.

Read about ObjectOutputStream and ObjectInputStream and try your best. Here's a little example.