TextFileOperations

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Formatter;
import java.util.List;
import java.util.Scanner;

public class ReadFile{

    private Scanner scan;

    public void openFile(){
        try{
            scan = new Scanner(new File("Input.txt"));
        }
        catch(FileNotFoundException ex){
            System.err.println("File not found!");
        }
    }

    public void readWriteFile(){
        List<Double> priceList = new ArrayList<Double>();
        List<String> productList = new ArrayList<String>();
        String product = "";
        Formatter formatter = null;
        DecimalFormat df = new DecimalFormat("#.00");
        while(scan.hasNext()){
            product = scan.next();
            double price = Double.parseDouble(scan.next());
            priceList.add(price);
            productList.add(product);
            Collections.sort(priceList);
//          System.out.printf("%s %s\n", priceList, product);
        }
        for (int i = 0; i < priceList.size(); i++) {
            System.out.printf("%s %s\n", df.format(priceList.get(i)), productList.get(i));
        }
        try{
            formatter = new Formatter("Output.txt");
            for (int i = 0; i < priceList.size(); i++) {
                formatter.format("%s %s\r\n", df.format(priceList.get(i)), productList.get(i));
            }
        }
        catch(IOException ioex){
            System.err.println("IO Exception occured.");
        }
        finally{
            formatter.close();
        }
    }

    public void closeFile(){
        scan.close();
    }
}


public class TextFileOperations{

    public static void main(String[] args){
        ReadFile rf = new ReadFile();
        rf.openFile();
        rf.readWriteFile();
        rf.closeFile();
    }
}