9. List of Products

import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Locale;
import java.util.Scanner;


public class _09_ListOfProducts {
    public static void main(String args[]) {

        Locale.setDefault(Locale.ROOT);
        File file = new File("ListOfProducts/input.txt");
        ArrayList<Product> products = new ArrayList<Product>();
        try {
            Scanner sc = new Scanner(file);
            while (sc.hasNext()) {
                products.add(new Product(sc.next(), sc.nextDouble()));
            }
        } catch (FileNotFoundException e) {
            System.out.println("Error");
        }

        Collections.sort(products);
        try {
            PrintWriter pw = new PrintWriter (new File("ListOfProducts/output.txt"));
            for (Product product : products) {
                pw.println(product.toString());
            }
            pw.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }

    }



}
class Product implements Comparable <Product>{
    private String name;
    private double price;
    Product (String name, double price) {
        this.name = name;
        this.price = price;
    }
    @Override
    public String toString() {
        DecimalFormat formatter = new DecimalFormat("#0.00");
        return formatter.format(this.price) + " " + this.name;
    }
    @Override
    public int compareTo(Product arg) {
        if(this.price < arg.price)
            return -1;
        else if (this.price > arg.price)
            return 1;
        return 0;
    }
}