Display Loop Results In TextArea Instead Of Command Window

[Brandon Buchanan]

Hi everyone. This is my first post with coderanch.com and I am definitely a novice when it comes to programming. That being said, I hope you can help me with this issue that I am having. I have everything in my code working properly except for the fact that the payment amounts are being displayed in the command window and I need to display them in the text area. I have been scouring google and I just can't seem to find a way to move the results to the text area, so any help you could give would be much appreciated!

I realize that I am telling the results to go to the command window by using the System.out.printf but I just can't figure out how or what to change that to, in order to get it to put the output into the textArea of the GUI??

Thanks, you all are awesome, and I hope you can help!

Here is my code:

//import necessary libraries
import java.awt.*;
import java.awt.event.*;
import java.text.DecimalFormat;

import javax.swing.*;
import javax.swing.text.*;

public class PaymentCalculatorWeek3 extends JPanel {

	//Declare all variables to be used
    private JButton button1;
    private JButton button2;
    private JButton button3;
	private JLabel label1;
    private JLabel label2;
    private JLabel label3;
    private JTextField textField1;
    private JTextField textField2;
	private JTextArea textArea1;
	private JComboBox termList;

    double[] interest = {5.35, 5.5, 5.75}; 
    int[] term = {7, 15, 30};             
    double numMonths = 0;				
    double monthlyInterest = 0;			
    double monthlyPayment = 0;				
	double principlePayment = 0;	 
	double interestPayment = 0;		 
	double balance = 0;				 

	java.text.DecimalFormat df= new java.text.DecimalFormat("$,###.00");
 // Formats dollar amount outputs to look like money


	public PaymentCalculatorWeek3() {

		super(new BorderLayout());

		label1 = new JLabel ("Loan Amount (eg. $200,000 = 200000): ", JLabel.LEFT);
		textField1 = new JTextField(10);

		label2 = new JLabel ("Term Length/Interest Rate: ", JLabel.LEFT);

		String[] termStrings = { "7 years at 5.35%", "15 years at 5.5%", "30 years at 5.75%" };
		
		termList = new JComboBox(termStrings);
		termList.setSelectedIndex(0);

		//Create the 1st button that also has a listener event to perform an action when clicked
		button1 = new JButton("Calculate");
        button1.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
                button1ActionPerformed(evt);
            }
        });

		//Create the 2nd button that also has a listener event to perform an action when clicked
		button2 = new JButton("Clear/Reset");
        button2.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
                button2ActionPerformed(evt);
            }
        });

		//Create the 3rd button that also has a listener event to perform an action when clicked
		button3 = new JButton("Quit");
        button3.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
                button3ActionPerformed(evt);
            }
        });
	
		//Add the final fields that will display the monthly payment after it is calculated
 		label3 = new JLabel("Your Monthly Payment is: ");
		textField2 = new JTextField();
		textField2.setEditable(false);

		textArea1 = new JTextArea(20,20);
		JScrollPane scrollPane = new JScrollPane(textArea1);
		scrollPane.setPreferredSize(new Dimension(200,200));
		textArea1.setEditable(false);

/*
Panel Layouts in the next section inspired by the FormattedTextFieldDemo.java found on this page: 
//http://docs.oracle.com/javase/tutorial/uiswing/components/formattedtextfield.html#format

put the labels into a specific panel layout
*/
		JPanel labelPane = new JPanel(new GridLayout(0,1));
		labelPane.add(label1);
		labelPane.add(label2);
		labelPane.add(label3);

		//put the textFields into a specific panel layout
		JPanel fieldPane = new JPanel(new GridLayout(0,1));
		fieldPane.add(textField1);
		fieldPane.add(termList);
		fieldPane.add(textField2);

		//put the buttons into a specific panel layout
		JPanel buttonPane = new JPanel(new GridLayout(0,1));
		buttonPane.add(button1);
		buttonPane.add(button2);
		buttonPane.add(button3);

//Create a boarder around the items and specify where to show each of the panels previously created.
		setBorder(BorderFactory.createEmptyBorder (20,20,20,20));
		add(labelPane, BorderLayout.WEST);
		add(fieldPane, BorderLayout.CENTER);
		add(buttonPane, BorderLayout.LINE_END);
		add(textArea1, BorderLayout.SOUTH);
	}


	//Setup what the quit button is going to do when clicked
    private void button3ActionPerformed(ActionEvent evt) {                                         
        System.exit(0);
    }

	//Setup what the clear button will do when clicked
    private void button2ActionPerformed(ActionEvent evt) {
			textField1.setText("");
			termList.setSelectedIndex(0);
            textField2.setText("");
			textArea1.setText("");
    }


	//Setup what the calculate button will do when clicked
    private void button1ActionPerformed(ActionEvent evt) {
	float principle;

/*
error handling to properly handle if user input is missing in order for calculation to be performed. 
The following code was inspired by fellow team member Robin Meredith
as well as the information found here:
http://docs.oracle.com/javase/tutorial/uiswing/components/dialog.html#features
*/
	Object source = evt.getSource();

		if(source == button1) {
		try {
			principle = Float.parseFloat(textField1.getText()); 
			} catch(NumberFormatException e) {
			// validates input.
			JOptionPane.showMessageDialog(null,
                   "Please enter a valid Loan Amount to continue. \n",
                   "MISSING OR INVALID INFORMATION", JOptionPane.ERROR_MESSAGE);
			{
        	    Toolkit.getDefaultToolkit().beep();
        	    return;
        	}
}			
}

		principle = Float.parseFloat(textField1.getText());
		monthlyInterest = (interest[termList.getSelectedIndex()] / (12 * 100));
// Term 0 is the 1st of 3 in the array
    	numMonths = (term[termList.getSelectedIndex()] * 12);

   		//Calculate the amortized monthly payment for each loan
    	monthlyPayment = principle *
                     ( monthlyInterest / (1 - Math.pow(1 + monthlyInterest, -numMonths)));
		textField2.setText(String.valueOf(df.format(monthlyPayment)));
//Display the monthly payment with a $ in front.

		balance = principle;
		interestPayment = balance * (interest[termList.getSelectedIndex()] / (12 * 100));
		principlePayment = monthlyPayment - interestPayment;

			for (int i=0; i < numMonths; ++i) {
				System.out.printf("Payment " + (i+1) + ": Interest Paid - $%.2f", + interestPayment );
				System.out.printf("    Remaining Balance: $%.2f\n", + (balance - principlePayment));
/* These 3 lines make the necessary subtractions so that the loop
 does not repeat on the same numbers over and over
*/
				balance = balance - principlePayment;
				interestPayment = balance * (interest[termList.getSelectedIndex()] / (12 * 100));
				principlePayment = monthlyPayment - interestPayment;
		}
}

	//Create the GUI and prepare to show on users screen
	private static void createAndShowGUI() {
		JFrame frame = new JFrame("PaymentCalculatorWeek3");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.add(new PaymentCalculatorWeek3());
		frame.pack();
		frame.setVisible(true);
	}

	//Show the GUI to user
	 public static void main(String[] args){

		createAndShowGUI();

	}

}

[Brandon Buchanan]

With a little more tinkering I got it figured out, guess we can close this one.

Thanks.

[Campbell Ritchie]

Welcome to the Ranch

Brandon Buchanan wrote: . . . guess we can close this one.

Thanks.

No, you can’t. Several things can be improved. Your code formatting is inconsistent, not helped by your using tab characters; you ought to use spaces for indenting. Your lines are so long they are difficult to read. I have edited your post by splitting the longest lines.
Why have you got the three panels with a single Component in a Grid Layout? Why don’t you use one panel with a three-component Grid Layout?
I presume you used the setText() method of the text field to set its output. You may find the String#format method better than DecimalFormat. It is similar to printf, but creates a String object.

[Brandon Buchanan]

Campbell Ritchie wrote:Welcome to the Ranch

Brandon Buchanan wrote: . . . guess we can close this one.

Thanks.

No, you can’t. Several things can be improved. Your code formatting is inconsistent, not helped by your using tab characters; you ought to use spaces for indenting. Your lines are so long they are difficult to read. I have edited your post by splitting the longest lines.
Why have you got the three panels with a single Component in a Grid Layout? Why don’t you use one panel with a three-component Grid Layout?
I presume you used the setText() method of the text field to set its output. You may find the String#format method better than DecimalFormat. It is similar to printf, but creates a String object.

Haha! I knew someone would probably chime in with how bad my code is... sorry. I am new to java programming and I don't yet have it all figured out, obviously!

So, let's take your response and piece it out.
1. Code formatting inconsistent, and using tab characters --- I didn't know that it wasn't kosher to use tab characters? Is there a reason why this is bad? Also, thank you for editing the lines, I never knew how long is too long?
2.The 3 panels with the single component in a GridLayout --- I was just copying and pasting as I was going and I didn't realize that this could be set up differently? Do you have an example of how I can use one panel with a three-component GridLayout?
3. Are you talking about the setText() on line 165? I didn't know that this could be done differently either? Also, I am not familiar with the "String#format" and I have only ever used the decimalformat in my past assignments.

I am glad that you responded, I would love to learn how to become a better coder, and these kinds of things really do help! For now, my new assignment is working exactly as I need it to, but it's different than what was posted here because what's posted here was previously not working. However, if you wouldn't mind coaching me through some of the "issues" with my code, I will make the changes in my final version of the assignment and then repost for your review?

Thanks so much!

[Campbell Ritchie]

If you know how to use printf, you will find String#format very easy to use.

int i = 2468;
String name = "Campbell";
String possibility = "anything";
String impossibility = "nothing";
double d = 123.456;
String output = String.format("%d who do we appreciate? %s! %<s is brilliant.%n" +
    "If you believe that, you\u2019ll believe %s%n%n" +
    "He bribed me £%12.2f",
    i, name, name.equals("Campbell") ? possibility : impossibility, d);
myTextField.setText(output);

>

[Campbell Ritchie]

As for tabs, try here.