Thread: BeginnerJOptionPane( input/output) homework problem. PLEASE HELP!

Hey all I have a few lab assignments due this Friday and I am new to JAVA and programming in general. This specific assignment requires me to write a program that calculates the total sales after each football game. There are 4 types of tickets: box, sideline, premium, and general admission. After each game, data is stored in a file... then output the number of tickets sold and total sale amount. Format your output with 2 decimal places.

Okay I know there is a I/O section and wasnt sure where to post this. I need some insight on how to use file input and output as well if anyone can give me some ideas how to "clean" my program up a little. I feel like its a lot longer than it has to be but again I am a total noob and only have little knowledge of programming. Here is my program:

import javax.swing.JOptionPane;
import java.text.DecimalFormat;
 
public class ticketsSold
{
	public static void main(String[] args)
	{
		String BoxSeat;
		String SideLine;
		String PremiumSeat;
		String GeneralSeat;
		double boxCost = 250.00;
		double sideCost = 100.00;
		double premiumCost = 50.00;
		double generalCost = 25.00;
		double box;
		double side;
		double premium;
		double general;
		String newDecimal;
		String newDecimal1;
		String newDecimal2;
		String newDecimal3;
		String newDecimal4;
 
		BoxSeat =
			JOptionPane.showInputDialog("Enter how many box tickets were sold: ");
			box = Double.parseDouble(BoxSeat);
 
		SideLine =
			JOptionPane.showInputDialog("Enter how many sideline tickets were sold: ");
			side = Double.parseDouble(SideLine);
 
		PremiumSeat =
			JOptionPane.showInputDialog("Enter how many premium tickets were sold: ");
			premium = Double.parseDouble(PremiumSeat);
 
		GeneralSeat =
			JOptionPane.showInputDialog("Enter how many general tickets were sold: ");
			general = Double.parseDouble(GeneralSeat);
 
		double totalBox = (box * boxCost);
		double totalSide = (side * sideCost);
		double totalPremium = (premium * premiumCost);
		double totalGeneral = (general * generalCost);
		double grandTotal = (totalBox + totalSide + totalPremium + totalGeneral);
 
		DecimalFormat formatter = new DecimalFormat("#0.00");
 
		newDecimal = (formatter.format(grandTotal));
		newDecimal1 = (formatter.format(totalBox));
		newDecimal2 = (formatter.format(totalSide));
		newDecimal3 = (formatter.format(totalPremium));
		newDecimal4 = (formatter.format(totalGeneral));
 
 
		JOptionPane.showMessageDialog(null, "The total number of $250.00 box seats sold this"
									 + " week: " + box + " seats netting: $"
									 + newDecimal1 + "\nThe total number of $100.00 sideline"
									 + " seats sold this week: " + side + " tickets"
									 + " netting: $" + newDecimal2 + "\nThe total number"
									 + " of $50.00 premium seats sold this week: "
									 + premium + " seats netting: $" + newDecimal3
									 + "\nThe total number of $25.00 general seats sold this"
									 + " week: " + general + " seats netting: $"
									 + newDecimal4 + "\nThe grand total of sales for the"
									 + " MCC football stadium this week is: $" + newDecimal
									 + "", "MCC Stadium Report", JOptionPane.INFORMATION_MESSAGE);
 
									 System.exit(0);
	}
}

This is my output Dialog Box.

output.jpg

can give me some ideas how to "clean" my program up a little

are there any compilation errors? runtime errors? bugs?
if it does not have any errors, i think experience and practice will make you create a better coding, algorithm
just continue programming as long as you enjoy it

Format your output with 2 decimal places.

you can use printf method to format the output i suggest you to read this tutorial for printf
Java For Complete Beginners - formatted strings
you can also use String.format to format you output
String (Java Platform SE 7 )

I need some insight on how to use file input and output

have you tried to use/read some IO classes in java that can support what you want to do?
if not, here are the links

for java.io.File File (Java Platform SE 7 )

you can read files using these classes:
java.io.FileReader FileReader (Java Platform SE 7 )
java.io.BUfferedReader BufferedReader (Java Platform SE 7 )

you can write on files using these classes:
java.io.FileWriter FileWriter (Java Platform SE 7 )
java.io.BufferedWriter BufferedWriter (Java Platform SE 7 )

there are another way of reading/writing on files aside from those i gave,
but you can stick to that as for starters.

try to do that, and if there is a problem, just ask here and we are going to help you

There are no compiler errors and the program runs just fine. I was just curious if there are any shortcuts to make it well, shorter! haha... As far as input and output I know I can import the java.io.* class and use FileWriter, PrintWriter etc... I am just unsure of how to even code it into the program. I am the type of learner that has to see it done and then explained why it works like that. I will take a look at some of the links you posted. Thanks!

--- Update ---

Originally Posted by dicdic

are there any compilation errors? runtime errors? bugs?
if it does not have any errors, i think experience and practice will make you create a better coding, algorithm
just continue programming as long as you enjoy it


you can use printf method to format the output i suggest you to read this tutorial for printf
Java For Complete Beginners - formatted strings
you can also use String.format to format you output
String (Java Platform SE 7 )



have you tried to use/read some IO classes in java that can support what you want to do?
if not, here are the links

for java.io.File File (Java Platform SE 7 )

you can read files using these classes:
java.io.FileReader FileReader (Java Platform SE 7 )
java.io.BUfferedReader BufferedReader (Java Platform SE 7 )

you can write on files using these classes:
java.io.FileWriter FileWriter (Java Platform SE 7 )
java.io.BufferedWriter BufferedWriter (Java Platform SE 7 )

there are another way of reading/writing on files aside from those i gave,
but you can stick to that as for starters.

try to do that, and if there is a problem, just ask here and we are going to help you

Also, can I use printf when I have to show my output in a dialog box?

Okay. Let me give you a simple way to learn how to read and write to files using those classes.

We will learn how to read it first.
First, create a file (hello.txt) on you computer, put some text on the file.
then create a new java file.
that java file will read the file hello.txt

Originally Posted by dicdic

Okay. Let me give you a simple way to learn how to read and write to files using those classes.

We will learn how to read it first.
First, create a file (hello.txt) on you computer, put some text on the file.
then create a new java file.
that java file will read the file hello.txt

Okay so I create a file ____.txt and then a new file in java. Next steps?

sorry for late response, its only 8:00 am here.. so i think i can assist you this whole day since i am not busy

okay, next were going to open that file and read using FileReader.

FileReader:
Convenience class for reading character files. The constructors of this class assume that the default character encoding and the default byte-buffer size are appropriate. To specify these values yourself, construct an InputStreamReader on a FileInputStream.
FileReader is meant for reading streams of characters. For reading streams of raw bytes, consider using a FileInputStream.
-that is from Java Doc
FileReader has 3 constructor:
FileReader(File file) - Creates a new FileReader, given the File to read from.
FileReader(FileDescriptor fd) - Creates a new FileReader, given the FileDescriptor to read from.
FileReader(String fileName) - Creates a new FileReader, given the name of the file to read from.

For now, we are going to use third one. FileReader(String fileName)
How to declare a FileReader? here's how:
first import FileReader: java.io.FileReader
next we will create an object reference variable for FileReader:
FileReader (variable name) = new FileReader(<path of your file that will going to read>);
new keyword will make us create new Object.
next to it is the constructor.
I think it throws FileNotFoundException, so make sure that you handle it..
try it now

Originally Posted by dicdic

sorry for late response, its only 8:00 am here.. so i think i can assist you this whole day since i am not busy

okay, next were going to open that file and read using FileReader.

FileReader:
Convenience class for reading character files. The constructors of this class assume that the default character encoding and the default byte-buffer size are appropriate. To specify these values yourself, construct an InputStreamReader on a FileInputStream.
FileReader is meant for reading streams of characters. For reading streams of raw bytes, consider using a FileInputStream.
-that is from Java Doc
FileReader has 3 constructor:
FileReader(File file) - Creates a new FileReader, given the File to read from.
FileReader(FileDescriptor fd) - Creates a new FileReader, given the FileDescriptor to read from.
FileReader(String fileName) - Creates a new FileReader, given the name of the file to read from.

For now, we are going to use third one. FileReader(String fileName)
How to declare a FileReader? here's how:
first import FileReader: java.io.FileReader
next we will create an object reference variable for FileReader:
FileReader (variable name) = new FileReader(<path of your file that will going to read>);
new keyword will make us create new Object.
next to it is the constructor.
I think it throws FileNotFoundException, so make sure that you handle it..
try it now

Okay just logged in. I am going to try now!

--- Update ---

Alright. So i am having trouble becasue im not sure what the coding is supposed to look like. Can you Show me an example?

just paste here the code you have created. and i'm gonna check what is wrong with your code

Originally Posted by dicdic

just paste here the code you have created. and i'm gonna check what is wrong with your code

I couldnt figure out how to even write the code. I need a guideline of a basic example to get started. Sorry :/ for some reason this is really hard for me to figure out lol

Originally Posted by brobertson300

I couldnt figure out how to even write the code. I need a guideline of a basic example to get started. Sorry :/ for some reason this is really hard for me to figure out lol

You don't know how to write a code?
hmm, so I think you should study the basics first.
Since you have internet, try to visit this link:
Java Tutorial
that is a java tutorial for beginners.

Originally Posted by dicdic

You don't know how to write a code?
hmm, so I think you should study the basics first.
Since you have internet, try to visit this link:
Java Tutorial
that is a java tutorial for beginners.

No No haha... I know how to write code. I am just unsure of how to get the program to read data from a .txt file. This is what I have so far and need guidance on the next steps. I used Scanner infile = new Scanner(new FileReader("__.txt")

import javax.swing.JOptionPane;
import java.text.DecimalFormat;
import java.io.*;
 
public class ticketsSold
{
	public static void main(String[] args)
	{
		String BoxSeat;
		String SideLine;
		String PremiumSeat;
		String GeneralSeat;
		double box;
		double side;
		double premium;
		double general;
		String newDecimal;
		String newDecimal1;
		String newDecimal2;
		String newDecimal3;
		String newDecimal4;
 
		Scanner infile = new Scanner(new fileReader("TicketInvoice");
 
		BoxSeat =
			JOptionPane.showInputDialog("Enter how many box tickets"
									   + "were sold: ");
			box = inFile.nextInt();
 
		SideLine =
			JOptionPane.showInputDialog("Enter how many sideline tickets"
									   + "were sold: ");
			side = inFile.nextInt();
 
		PremiumSeat =
			JOptionPane.showInputDialog("Enter how many premium tickets"
									   + "were sold: ");
			premium = inFile.nextInt();
 
		GeneralSeat =
			JOptionPane.showInputDialog("Enter how many general tickets"
									   + "were sold: ");
			general = inFile.nextInt();
 
		double totalBox = (box * boxCost);
		double totalSide = (side * sideCost);
		double totalPremium = (premium * premiumCost);
		double totalGeneral = (general * generalCost);
		double grandTotal = (totalBox + totalSide + totalPremium
							+ totalGeneral);
 
		DecimalFormat formatter = new DecimalFormat("#0.00");
 
		newDecimal = (formatter.format(grandTotal));
		newDecimal1 = (formatter.format(totalBox));
		newDecimal2 = (formatter.format(totalSide));
		newDecimal3 = (formatter.format(totalPremium));
		newDecimal4 = (formatter.format(totalGeneral));
 
 
		JOptionPane.showMessageDialog(null, "The total number of $250.00"
									 + "box seats sold this"
									 + " week: " + box + " seats netting: $"
									 + newDecimal1 + "\nThe total number of"
									 + "$100.00 sideline"
									 + " seats sold this week: " + side
									 + " tickets"
									 + " netting: $" + newDecimal2 + "\nThe"
									 + "total number"
									 + " of $50.00 premium seats sold"
									 + "this week: "
									 + premium + " seats netting: $"
									 + newDecimal3
									 + "\nThe total number of $25.00 general"
									 + "seats sold this"
									 + " week: " + general + " seats"
									 + "netting: $"
									 + newDecimal4 + "\nThe grand total"
									 + "of sales"
									 + "for the"
									 + " MCC football stadium this week is: $"
									 + newDecimal
									 + "", "MCC Stadium Report"
									 +"", JOptionPane.INFORMATION_MESSAGE);
 
									 System.exit(0);
	}
}

I guess you have compilation error right?
FileReader throws FileNotFoundException, it is either you catch it using try catch or throws it.

Scanner infile = new Scanner(new fileReader("TicketInvoice");

you parameter is String, that must be the file path of your file. something like C:\File.txt

Originally Posted by dicdic

I guess you have compilation error right?
FileReader throws FileNotFoundException, it is either you catch it using try catch or throws it.


you parameter is String, that must be the file path of your file. something like C:\File.txt

Okay I am converting over to the Scanner class instead of using dialog boxes (JOptionPane) because thats what my teacher wants. I will post what I have in a few minutes.

--- Update ---

Originally Posted by dicdic

I guess you have compilation error right?
FileReader throws FileNotFoundException, it is either you catch it using try catch or throws it.


you parameter is String, that must be the file path of your file. something like C:\File.txt

import java.util.Scanner;
import java.text.DecimalFormat;
import java.io.*;
 
public class ticketsSold
{
	public static void main(String[] args) throws IOException
	{
		double box;
		double side;
		double premium;
		double general;
		String newDecimal;
		String newDecimal1;
		String newDecimal2;
		String newDecimal3;
		String newDecimal4;
 
		Scanner infile = new Scanner(new fileReader("TicketInvoice.txt"));
 
		System.out.println("Enter how many box tickets"
						  + "were sold: ");
		box = inFile.nextInt(BoxSeat);
 
		System.out.println("Enter how many sideline tickets"
						  + "were sold: ");
		side = inFile.nextInt(SideLine);
 
		System.out.println("Enter how many premium tickets"
						  + "were sold: ");
		premium = inFile.nextInt(PremiumSeat);
 
		System.out.println("Enter how many general tickets"
						  + "were sold: ");
		general = inFile.nextInt(GeneralSeat);
 
		double totalBox = (box * boxCost);
		double totalSide = (side * sideCost);
		double totalPremium = (premium * premiumCost);
		double totalGeneral = (general * generalCost);
		double grandTotal = (totalBox + totalSide + totalPremium
							+ totalGeneral);
 
		DecimalFormat formatter = new DecimalFormat("#0.00");
 
		newDecimal = (formatter.format(grandTotal));
		newDecimal1 = (formatter.format(totalBox));
		newDecimal2 = (formatter.format(totalSide));
		newDecimal3 = (formatter.format(totalPremium));
		newDecimal4 = (formatter.format(totalGeneral));
 
 
		JOptionPane.showMessageDialog(null, "The total number of $250.00"
									 + "box seats sold this"
									 + " week: " + box + " seats netting: $"
									 + newDecimal1 + "\nThe total number of"
									 + "$100.00 sideline"
									 + " seats sold this week: " + side
									 + " tickets"
									 + " netting: $" + newDecimal2 + "\nThe"
									 + "total number"
									 + " of $50.00 premium seats sold"
									 + "this week: "
									 + premium + " seats netting: $"
									 + newDecimal3
									 + "\nThe total number of $25.00 general"
									 + "seats sold this"
									 + " week: " + general + " seats"
									 + "netting: $"
									 + newDecimal4 + "\nThe grand total"
									 + "of sales"
									 + "for the"
									 + " MCC football stadium this week is: $"
									 + newDecimal
									 + "", "MCC Stadium Report"
									 +"", JOptionPane.INFORMATION_MESSAGE);
 
									 System.exit(0);
	}
}

--- Update ---

Now my question is how does the program pick up the correct information from the .txt file and put it in the right place? I am still trying to figure out how this actually works. I created a .txt file in notepad the following values are stored in there like this:

250 5750
100 28000
50 3750
25 18750

These numbers represent ticket prices and tickets sold.

used nextLine() method of scanner. that returns a string.
try to print it

but make sure to handle it with try-catch. you might end up with NoSuchElementException I guess.

Originally Posted by dicdic

used nextLine() method of scanner. that returns a string.
try to print it

but make sure to handle it with try-catch. you might end up with NoSuchElementException I guess.

Okay so use nextLine instead of nextInt... What is try-catch?

--- Update ---

This is all messed up. I really cant figure out how to do this. Cant you show me a proper example? Doesnt have to be with my problem just something general

First fix the path of your FileReader.
that must be a path.
Scanner infile = new Scanner(new fileReader("TicketInvoice.txt"));
change "TicketInvoice.txt" to its full path.
it is okay to use not the full path, but for now, we are going to use its absolute path