Reading a desired line in a txt file

Question

How do I search for a specific entry in a text file that I append to?

I made a GUI to input the data in to, however I can read the whole file, but that is of no use to me as I am thinking from a Users perspective that if an earlier booking wants to be called on I am clueless on the understanding on how to do so. When I read the data back I am trying to instantiate an object.

Here some of my code:

search.addActionListener(new ActionListener()
    {
        public void actionPerformed(ActionEvent e)
        {
            String booking;
            String where;
            booking = JOptionPane.showInputDialog(" Booking Reference: ");    
            System.out.println("Booking Reference " + e.getActionCommand());
            if (booking.equals("Wales"))
            try{

            FileInputStream fstream = new FileInputStream("Wales.txt");
            // Use DataInputStream to read binary NOT text.
            BufferedReader br = new BufferedReader(new InputStreamReader(fstream));
            String strLine;

            while ((strLine = br.readLine()) != null)   {

            System.out.println (strLine);
           }

            in.close();
            }
            catch (Exception ex)
            {
            System.err.println("Error: " + ex.getMessage());
            }
            else if (booking.equals("Scotland"))
            try{

            FileInputStream fstream = new FileInputStream("Scotland.txt");

            DataInputStream in = new DataInputStream(fstream);
            BufferedReader br = new BufferedReader(new InputStreamReader(in));
            String strLine; 
            while ((strLine = br.readLine()) != null)   {

            System.out.println (strLine);
           }
            where = JOptionPane.showInputDialog("Which booking reference do you wish to search?: ");

            }
            catch (Exception ex)
            {
            System.err.println("Error: " + ex.getMessage());
            }
        }
    });

Eventually yes, that is on the to do list, but I wanted to try this way first. — user2129811, Mar 10 '13 at 22:04
BTW: The proper way of doing something basic first and later replacing it with The Right Thing (TM) is to define an interface and hide the basic code behind it. This way you don't have to rewrite your whole mess but only have to replace the interface's implementation. — xmjx, Dec 17 '13 at 10:42

score 1 · Answer 1 · edited May 23 '17 at 10:25

1

I think you're going to be better off exploring a file format such as XML, JSON or INI for handling this kind of thing. As you are starting to realize, a text file without a backing format is just that: a text file.

If you just want to read back some Key/Value pairs, try something like an INI file, using this Java INI library.

If you want to instantiate an object from a saved file, XML is a better choice. Saving an object to a text file, and reconstituting that object from the saved file is called Serialization.

edited May 23 '17 at 10:25

Community

1
1

answered Mar 10 '13 at 22:10

Robert Harvey

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Ok will look into Serialization then – user2129811 Mar 10 '13 at 22:19

Reading a desired line in a txt file

1 Answers1