Question 5: (10 marks) The owner of a photocopy store charges 5 cents per copy. In addition there is a setup fee for 2.5$ for each photocopying job. The store revenue from selling x copies is: revenue = 0.05x + 2.5 If it costs the owner 3 cents per copy,

Question 5: (10 marks) The owner of a photocopy store charges 5 cents per copy. In addition there is a setup fee for 2.5$ for each photocopying job. The store revenue from selling x copies is: revenue = 0.05x + 2.5 If it costs the owner 3 cents per copy, write a Java program that reads a text file which contains the sales of each day during a period of time then determines the total revenue, cost and profit over this period of time. (Profit = revenue-cost). (Put your Java code inside a try-catch block and don't forget to import the required library).

代碼:

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.text.DecimalFormat;

public class photocopy {
    public static void main(String[] args){
        // start try catch block
        try {
            // DecimalFormat class for rounding up to 2 places of decimla
            final DecimalFormat df = new DecimalFormat("#.##");

            // total revenue and total cost variable
            double totalRevenue = 0.0;
            double totalCost = 0.0;

            // totalNumberOfPhotocopies variable to store the total number of photocopies
            int totalNumberOfPhotocopies = 0;

            // open the file sales.txt
            File file = new File("sales.txt");

            // reading fie sales.txt line by line
            FileReader fileReader = new FileReader(file);
            BufferedReader br = new BufferedReader(fileReader);
            String line = "";
         
            while((line=br.readLine())!=null){
                // check if line is empty or not
                if(line.length()!=0){
                    // parsing the raed value to integer
                    int x = Integer.parseInt(line);

                    // calculating revenue from sales
                    double revenue = 0.05 * x + 2.5;

                    // adding revenue to total revenue
                    totalRevenue = totalRevenue + revenue;

                    // adding x to total totalNumberOfPhotocopies
                    totalNumberOfPhotocopies = totalNumberOfPhotocopies + x;
                }
            }

            br.close();

            // calculating total cost
            totalCost = totalNumberOfPhotocopies * 0.03;

            // calculating profit
            double profit = totalRevenue - totalCost;

            // displaying the profit
            System.out.println("Profit: $"+Double.valueOf(df.format(profit)));
             
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}