Ex9_ListOfProducts

package javaLoopsMethodsClasses;
import java.util.ArrayList;
import java.util.Collections;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.FileReader;
import java.io.Writer;

public class Ex9_ListOfProducts {

    public static void main(String[] args) {
        ArrayList<Product> products = new ArrayList<Product>();
        BufferedReader reader;
        Writer writer = null;
        try {
            reader = new BufferedReader(new FileReader("Products.txt"));
            String line = null;
            while ((line = reader.readLine()) != null) {
               String[] splittedLine = line.split(" ");
               products.add(new Product(splittedLine[0], Double.parseDouble(splittedLine[1])));
            }
            Collections.sort(products);

            writer = new BufferedWriter(new FileWriter("Output.txt"));
            for(Product product : products){
                writer.write(product.getPrice() + " " + product.getName() + "\r\n" );
            }
        }
        catch (Exception e) {
            System.out.println("Error");
        }
        finally {
               try {writer.close();} catch (Exception ex) {}
            }

    }

}


class Product implements Comparable<Product>{
    private String name;
    private double price;

    public Product(String name, double price){
        this.name = name;
        this.price = price;
    }

    public String getName(){
        return name;
    }

    public double getPrice(){
        return price;
    }

    public int compareTo(Product compareFruit) {

        double otherPrice = ((Product) compareFruit).getPrice();

        //ascending order
        if(this.price>otherPrice) return 1;
        else
        if(this.price==otherPrice) return 0;
        return -1;
    }
}