5-12 SalesReport

Post date: Apr 3, 2014 5:11:08 PM


This program opens a file containing the sales

amounts for 30 days. It calculates and displays

the total sales and average daily sales.


package salesreport;

import java.util.Scanner; // For the Scanner class.

import java.io.*; // For file I/O classes

import java.text.DecimalFormat; // For the DecimalFormat class

import javax.swing.JOptionPane; // For the JOptionPane class

public class SalesReport


public static void main(String[] args)throws IOException


final int NUM_DAYS = 30; // Number of days of sales.

String filename; // The name of the file to open.

double totalSales; // Total sales for period.

double averageSales; // Average daily sales.

// Get the name of the file.

filename = getFileName();

// Get the total sales from the file.

totalSales = getTotalSales(filename);

// Calculate the average.

averageSales = totalSales / NUM_DAYS;

// Display the total and average.

displayResults(totalSales, averageSales);




The getFileName method prompts the user to enter

the name of the file to open.

@return A reference to a String object containing

the name of the file.


public static String getFileName()


String file; // To hold the file name.

// Prompt the user to enter afile name.

file = JOptionPane.showInputDialog("Enter the name of the file\n"

+"containing 30 days of sales amount.");

// Return the name.

return file;



The getTotalSales method opens a file and

reads the daily sales amounts, accumulating

the total. The total is returned.

@param filename The name of the file to open.

@return The total of the sales amounts.


public static double getTotalSales(String filename)throws IOException


double total = 0.0; // Accumulator.

double sales; // A daily sales amount.

// Open the file.

File file = new File(filename);

Scanner inputFile = new Scanner(file);

// This loop processes the lines read from the file.

// until the end of the file is encountered.



// Read a double from the file.

sales = inputFile.nextDouble();

// Add sales to the value already in total.

total += sales;


// Close the file.

inputFile.close( );

// Return the total sales.

return total;



The displayResults method displays the total and

average daily sales.

@param total The total sales.

@param avg The average daily sales.


public static void displayResults(double total , double avg)


// Create a DecimalFormat object capable of formatting a dollar amount.

DecimalFormat dollar = new DecimalFormat( "#,###.00");

// Display the total and average sales.

JOptionPane.showMessageDialog(null,"The total sales for the period is $"+

dollar.format(total)+"\nThe average daily sales were $"+dollar.format(avg));