如何在文件中写入多个文本而不会覆盖它

Question

I have created a simple program that will create a bank account and balance This program will ask the number of accounts you want to create then you will input account number and balances.

Now the problem is when its writing new account number it just Overwriting it, so the text that entering in my file is only 1 line;

Here's my current code:

    import java.util.*;

import javax.swing.JOptionPane;

public class CreateBankFile {
    public static Formatter sample;
    public static int account;
    public static int balance;
    public static void main(String[] args) {
        createBank();
        createFile();
        addRecords();
        closeFile();
    }

    public static void createBank() {
        int loops = Integer.parseInt(JOptionPane.showInputDialog(null,
                "How many accounts \nyou wanted to create?"));
        for (int i = 1; i <= loops; i++) {
            account = Integer.parseInt(JOptionPane.showInputDialog(null,
                    "Enter account number:"));
            balance = Integer.parseInt(JOptionPane.showInputDialog(null,
                    "Enter balance:"));
        }
    }

    public static void createFile() {
        try {
            sample = new Formatter("BankAccounts.txt");
        } catch (Exception e) {
            System.out.println("You got an error!");
        }
    }

    public static void addRecords() {
        sample.format("%s%s", account + "\t", balance);
    }

    public static void closeFile() {
        sample.close();
        JOptionPane.showMessageDialog(null, "You successfully created bank accounts!");
    }
}

Thank you, hope you will answer this question

Answer 1

// create an output stream to the file in append mode rather than overwrite mode
FileOutputStream out = new FileOutputStream("BankAccounts.txt", true);
// create a Formatter which writes to this stream
Formatter formatter = new Formatter(out);

The Java tutorials and the javadoc are your friends. Use them.

Answer 2

Your method createBank stores only the last inputs for account and balance in the variables and addRecords is only called once.
Call addRecords inside the loop in createBank and createFile before createBank .

public static void main(String[] args) {
   createFile();
   createBank();
   closeFile();
}

public static void createBank() {
   int loops = Integer.parseInt(JOptionPane.showInputDialog(null,
           "How many accounts \nyou wanted to create?"));
   for (int i = 1; i <= loops; i++) {
       account = Integer.parseInt(JOptionPane.showInputDialog(null,
               "Enter account number:"));
       balance = Integer.parseInt(JOptionPane.showInputDialog(null,
               "Enter balance:"));
       addRecords();
   }
}

And add a newline in addRecords .