Write a program in Java that reads each line in a standard txt file, reverses it

Question

Write a program in Java that reads each line in a standard txt file, reverses its lines, and
writes them to another file.

For example: if the file infile.txt contains the lines

I went down to the river.
I set down on the bank.
I tried to think but couldn't.
So I jumped in and sank.

and you run ReverseTxtLines infile.txt outfile.txt then oufile.txt contains

So I jumped in and sank.
I tried to think but couldn't.
I set down on the bank.
I went down to the river.

Note: Use exception handling to detect improper inputs.

Explanation / Answer

ReverseTxtLines.java

import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintStream;
import java.util.ArrayList;
import java.util.Scanner;

public class ReverseTxtLines {

   public static void main(String[] args) throws FileNotFoundException {
       File file = new File("D:\infile.txt");
       File outputfile = new File("D:\outfile.txt");
       if(file.exists()){
           ArrayList<String> list = new ArrayList<String>();
       Scanner scan = new Scanner(file);
       while(scan.hasNextLine()){
           list.add(scan.nextLine());
       }
       PrintStream ps = new PrintStream(outputfile);
       for(int i=list.size()-1; i>=0; i--){
           ps.println(list.get(i));
       }
       ps.flush();
       ps.close();
       scan.close();
       System.out.println("outfile.txt file has been geenrated");
       }
       else{
           System.out.println("Input file does not exist");
       }
      
   }

}

Output:

outfile.txt file has been geenrated

outfile.txt

So I jumped in and sank.
I tried to think but couldn't.
I set down on the bank.
I went down to the river.

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