Java project output problem. Can't output objects from a method.

[clook]

I'm trying to create a bookstore calculation program with two classes, a presentation and computation class. Here is my code for the presentation class:

import javax.swing.*;
import java.awt.event.*;
import java.text.*;
import java.awt.*;

public class ch4Book extends JFrame implements ActionListener
{

	// All the GUI objects
	JPanel mainPanel = new JPanel();
	JLabel companyLabel = new JLabel("       OrderBook Inc.         ");
	JTextField titleTextField = new JTextField(30);
	JTextField quantityTextField = new JTextField(15);
	JTextField priceTextField = new JTextField(15);
	JButton calculateButton = new JButton(" Calculate   ");
	JTextArea outputTextArea = new JTextArea("Your Total Cost:", 10, 25);
	JScrollPane outputScrollPane = new JScrollPane(outputTextArea);
	

	
	
	public static void main(String[] args)
	{
		//create an object of the class and code the close button
		ch4Book myCost = new ch4Book();
		myCost.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	}
	
	public ch4Book()
	{
		designFrame();
	}
	
	public void designFrame()
	{
		//add the components to the mainPanel
		mainPanel.add(companyLabel);
		mainPanel.add(new JLabel("       Title            "));
		mainPanel.add(titleTextField);
		mainPanel.add(new JLabel("    Quantity   "));
		mainPanel.add(quantityTextField);
		mainPanel.add(new JLabel("    Price       "));
		mainPanel.add(priceTextField);
		mainPanel.add(calculateButton);
		mainPanel.add(outputScrollPane);
		
		//add the listeners
		calculateButton.addActionListener(this);
		
		
		//add the panel to the frame
		add(mainPanel);
		setSize(500,500);
		setVisible(true);
		
	}
	
	public void actionPerformed(ActionEvent evt)
	{
		getInput();
		displayOutput();
		clear();
		
	}
	
	public void getInput()
	{
		//input variables

		double  priceDouble;
		int quantityInteger;
		String titleString;
		

		priceDouble = Double.parseDouble(priceTextField.getText());
		quantityInteger = Integer.parseInt(quantityTextField.getText());
		titleString = titleTextField.getText();
		
	    
		//send the input the calculation class
		Cost myTotalCost = new Cost(priceDouble, quantityInteger);
		displayOutput();
		
		
	}
	
	public void displayOutput()
	{
		// object to format to currency
		DecimalFormat formatDecimalFormat = new DecimalFormat("$0.00");
		
		//variables to store the retrieved values from the computation class
		double  subTotalDouble, totalCostDouble;
		int counterInteger;
		
		Cost myTotalCost = new Cost();
	    
	    subTotalDouble = myTotalCost.getSubTotal();
	    totalCostDouble = myTotalCost.getTotalCost();
	    counterInteger = myTotalCost.getCounterInteger();
	    
	    
	    outputTextArea.append('\n' + "Book Title:  " + titleString +
	    		'\n' + " Quantity  " + formatDecimalFormat.format(quantityInteger)+
	    		'\n' + "Number of Customers  " + counterInteger);
	    
		
	}
	
	public void clear()
	{
		titleTextField.setText("");
		quantityTextField.setText("");
		priceTextField.setText("");
	}
}

Problem is, I'm unable to output the variables and objects from getInput()

I'm not sure why.. can someone help me with this?

 

[KataKoniK]

Hi there,

I would recommend taking a step back and breaking down the problem into smaller parts. First, make sure that your getInput() method is properly receiving and storing the input values. You can do this by printing out the values you are retrieving from the text fields and checking if they match the user inputs.

Next, make sure that your displayOutput() method is properly accessing the values from the computation class and displaying them in the output text area. Again, you can print out the values to check if they are being retrieved correctly.

If these two parts are working correctly, then the issue may lie in your designFrame() method or in the way you are calling the methods in your actionPerformed() method. Double check these areas and make sure everything is connected properly.

If you are still having trouble, consider reaching out to a fellow programmer or seeking help from a programming forum. Sometimes having a fresh pair of eyes can help identify the problem. Good luck with your project!

 

[piercas]

It seems like you have not properly declared and initialized your variables in the displayOutput() method. Make sure you have declared and initialized the variables subTotalDouble, totalCostDouble, and counterInteger before trying to output them in your outputTextArea. Also, make sure you are calling the displayOutput() method after calling the getInput() method in your actionPerformed() method.