Question

I know how to get value from JTextField and Write it into a text file in Java language.
Here is my code :

public class createfile {
    private Formatter x;

    public void openFile() {
        try {
            x = new Formatter("c:\\definition.txt");
        } catch (Exception e) {
            System.out.println("Error");
        }
    }

    private void addRecords() {
        x.format(null, jTextField3);
    }

    public void closFile() {
        x.close();
    }
}

It works properly and writes the value of jTextField3 to a file called “definition.txt”. BUT If the user runs the program again, and enters new value in jTextField3, then “definition.txt” will be filled with new data ! and the previous data will lost !
I do not want to be like that ! I want to keep all the data which every time enters by user.
how should I change my code ?
Thank you !

Answer 1

You want to append to the file instead of overwriting it. The Formatter constructor which takes a file name doesn’t seem up to the job. I suggest you create a FileOutputStream where you can explicitely require appending. You can pass that stream to the Formatter constructor instead of the raw file name.

x = new Formatter(new FileOutputStream("c:\\definition.txt", true));