Question

Using java, I need to make a program that reverses a file.

The program will read the text file character by character, push the characters into a stack, then pop the characters into a new text file (with each character in revers order)

EX: Hello World                       eyB

      Bye            becomes    dlroW olleH

I have the Stack and the Linked List part of this taken care of, I'm just having trouble connecting the stack and the text file together and then reversing it

public class StackReverser {

    public static void main(String[] args) throws IOException
    {
      Stack myStack = new Stack();
      myStack.push(fileName);
    
      System.out.println(myStack.peek());
      System.out.println(myStack.pop());
             
    }

    private void readFile() throws FileNotFoundException
    {
        String fileName = "input.txt";
        File file;
            file = new File(fileName);
        Scanner fileScanner;
            fileScanner = new Scanner(file);
        while(fileScanner.hasNextLine())
        {
            String line = fileScanner.nextLine();
          
        }
      
    }
  
    private void reverseFile()
    {
  
    }
  
}

Answer 1

Here is the answer for your question in Java Programming Language.

Kindly upvote if you find the answer helpful.

How to reverse the file content with stack:

• Don't push file name to stack object as you did in main method.
• Instead pass the stack object to readfile method and push each character of file to the stack.
• Call reverseFile() method and pop each character and print it to output file.

###################################################

CODE :

import java.io.BufferedWriter; import java.io.File; import java.io.FileNotFoundException; import java.io.FileWriter; import java.io.IOException; import java.util.Scanner; import java.util.Stack; public class StackReverser { public static void main(String[] args) throws IOException { //Create stack object Stack myStack = new Stack(); //Create current class object StackReverser obj = new StackReverser(); //Call readFile and reverseFile methods one-by-one by passing stack as argument obj.readFile(myStack);    obj.reverseFile(myStack);    System.out.println(); } private void readFile(Stack myStack) throws FileNotFoundException { //Required variables String fileName = "input.txt"; String line; //Create file object and open file with scanner objetc File file; file = new File(fileName); Scanner fileScanner; fileScanner = new Scanner(file);    //For eachline in the file while(fileScanner.hasNextLine()) { //Store the lineto 'line' variable line = fileScanner.nextLine(); //Push each character of the line to the stack for(int i = 0;i<line.length();i++){ myStack.push(line.charAt(i)); } } } private void reverseFile(Stack myStack) throws IOException { String fileName = "output.txt"; String line; //Create file object and open file with BufferedWriter objetc File file; file = new File(fileName); BufferedWriter fileWriter; fileWriter = new BufferedWriter(new FileWriter(file));    //Print each character from the top of the file to new text file and pop it out from the stack while(!myStack.isEmpty()){ fileWriter.write(myStack.peek().toString()); myStack.pop(); } fileWriter.flush(); fileWriter.close(); } }

input.txt

Hello World eyB

#########################################################

SCREENSHOTS :

Please see the screenshots of the code below for the indentations of the code.

input.txt

#########################################################

OUTPUT :

output.txt file

Any doubts regarding this can be explained with pleasure :)