Question

The problem: I need to delete a reservation. The user gives me the hour of the reservation trough a SimpleInOutDialog. Then I search with a buffered reader if the file contains that hour.

What I need to do , is delete that line with the hour and 2 lines beneath it because there are the data of the reservation. Here’s and example of the txtFile:

10:00
Niel Butaye
1
09:00
Tom Mullue
2

So I look for 10:00 and then 10:00 , Niel Butaye and 1 need to be deleted.
The code that I already have is:

public void setAnnulation() {
        //make SimpleInOutDialog      
                SimpleInOutDialog  input = new SimpleInOutDialog("Delete reservation");
                reservation= input.readString("Give the hour (hh:mm)");
            try{

            BufferedReader br = new BufferedReader(new FileReader("L:\\Documents/Informatica/6de jaar/GIP/Reservations.txt"));
            HashSet<String> hs = new HashSet<String>();
            int i = 0;
            while ((line = br.readLine()) != null)
            {
                i++;
                hs.add(br.readLine());

            }
            if(hs.contains(reservation)){
                //klant bestaat
             input.showString("The Reservation is being deleted", "");...}





            }catch (Exception e){//Catch wanneer er errors zijn
                System.err.println("Error: " + e.getMessage());}


    }

Where the “…” needs to come the code. Any help ?

Answer 1

Your approach is foul. Try to handle the file sequentially. Remember that you need to write it anyway so try this:

(open file for reading, open new file for writing)

1. readLine -> String variable
2. if readLine is your reservation read the next two lines without doing anything.
3. if not 2) then write the line to the new file.
4. flush new file and close both.
5. delete old file and move new one to old name.

done.