Thread: Problem with overwriting a file using IO package

Hello marksquall and welcome to the Java Programming Forums

I have re-wrote this code for you in a way that I would do it and added comments so you can see whats going on.

import java.io.*;
import java.util.Scanner;
 
public class FileWriteAndRead {
 
    public static int myNumber;
    public static int getNumber;
    public static int endNumber;
 
    public static void main(String args[]) {
 
        // Read user input using the scanner class
        System.out.println("Please enter a number: ");
        Scanner sc = new Scanner(System.in);
        myNumber = sc.nextInt();
 
        // Call write file method
        writeFile();
 
    }
 
    public static void writeFile() {
 
        // Convert integer value to string for writing file
        String myString = Integer.toString(myNumber);
 
        // Write to file
        try {
            Writer output = null;
            File file = new File("sample.txt");
            output = new BufferedWriter(new FileWriter(file));
            output.write(myString);
            output.close();
            System.out.println("File written");
 
            // Call the read file method to get the saved number
            readFile();
 
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
 
    public static void readFile() {
 
        System.out.println("Reading file");
 
        // Read the number value from the saved file
        try {
            FileInputStream in = new FileInputStream("sample.txt");
            BufferedReader br = new BufferedReader(new InputStreamReader(in));
            String strLine;
 
            while ((strLine = br.readLine()) != null) {
                getNumber = Integer.parseInt(strLine);
            }
 
            // Call calculations method
            calculations();
 
        } catch (Exception e) {
            System.out.println(e);
        }
 
    }
 
    public static void calculations() {
 
        // Take our integer value and * by 100
        endNumber = (getNumber * 100);
        System.out.println(getNumber + " * 100 = " + endNumber);
 
        // Call rewrite method
        reWriteFile();
 
    }
 
    public static void reWriteFile() {
 
        System.out.println("Saving to file");
 
        // Convert integer value to string for writing file
        String myString = Integer.toString(endNumber);
 
        // Write to file
        try {
            Writer output = null;
            File file = new File("sample.txt");
            output = new BufferedWriter(new FileWriter(file));
            output.write(myString);
            output.close();
            System.out.println("File written");
 
        } catch (IOException e) {
            e.printStackTrace();
        }
 
        System.out.println("");
        System.out.println("All done!");
 
    }
 
}

I've also edited and fixed your original code.

import java.io.*;
 
public class FileWriteAndRead {
 
    public static String name;
 
    public static void main(String args[]) throws IOException {
 
        //for reading user input
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        //for writing file
        BufferedWriter bfw = new BufferedWriter(new FileWriter("sample.txt"));
        //for writing file
        BufferedWriter bfw2 = new BufferedWriter(new FileWriter("sample.txt"));
        //for reading in file
        FileInputStream in = new FileInputStream("sample.txt");
        BufferedReader br2 = new BufferedReader(new InputStreamReader(in));
 
        String number = "";
        System.out.print("Please enter a number: ");
        try {
            number = br.readLine();
            bfw.write(number);
            bfw.close();
        } catch (Exception ioe) {
        }
 
        System.out.println("The number was successfully written in a file.");
 
        try {
                name = br2.readLine();
                name = ((Integer.parseInt(name))*100) + " ";
                bfw2.write(name);
                bfw2.close();
 
        } catch (Exception e) {
            System.out.println(e);
        }
 
        System.out.println("The new content of the file is: " + name);
        br2.close();
 
    }// end of main
}// end of class

Glad we could help MarkSquall,

We're here any time