Exceptions Java Form 2D array list

[Jayden Brymatt]

Hi all,

This program should generate a form where the user puts in the amount in minutes, greater than 0 and less than 240, and the money earned, greater than 0. Once the user clicks Enter the values should be added a 2D array. When I try and run this program these are the errors that I'm receiving:

Exception in thread "AWT-EventQueue-0" java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
	at java.util.ArrayList.rangeCheck(ArrayList.java:635)
	at java.util.ArrayList.get(ArrayList.java:411)
	at tutoringInterface.enterActionPerformed(tutoringInterface.java:185)
	at tutoringInterface.access$100(tutoringInterface.java:9)
	at tutoringInterface$2.actionPerformed(tutoringInterface.java:62)

There's quite a few more, but the bottom three are the only ones that indicate specific lines. Here is my code:

import java.io.*;
import java.util.*;
import javax.swing.*;

/**
 *
 * @author 
 */
public class tutoringInterface extends javax.swing.JFrame {
    /**
     * Creates new form tutoringInterface
     */
    static List<List<Double>> info = new ArrayList<List<Double>>();
    static List<Double> info2 = new ArrayList<>();
    final double minimumWage = 7.25;
    public tutoringInterface() {
        initComponents();
    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        min = new javax.swing.JTextField();
        jLabel1 = new javax.swing.JLabel();
        jLabel2 = new javax.swing.JLabel();
        mon = new javax.swing.JTextField();
        enter = new javax.swing.JButton();
        jScrollPane1 = new javax.swing.JScrollPane();
        textBox = new javax.swing.JTextArea();
        jPanel1 = new javax.swing.JPanel();
        report = new javax.swing.JButton();
        exit = new javax.swing.JButton();
        jScrollBar1 = new javax.swing.JScrollBar();

    private void enterActionPerformed(java.awt.event.ActionEvent evt) {                                      
        double minute = Double.parseDouble(min.getText().toString());
        if (minute < 0 || minute > 240) {
            while (minute < 0){
            try {
                minute = Double.parseDouble(min.getText().toString());
            }
            catch (NumberFormatException exception) {
            throw new IllegalArgumentException("Invalid input. Please try again.");
            }
        }
        }
        double monies = Double.parseDouble(min.getText().toString());
        if (monies < 0) {
            while (monies < 0){
            try {
                monies = Double.parseDouble(mon.getText().toString());
            }
            catch (NumberFormatException exception) {
            System.out.print("Invalid input.  Please try again.");
            }
        }
        }
        int i = 0, j = 0;
        List<Double> test = info.get(i);
        do {
        if (test == null){
        info.get(i).set(i, minute);
        info.get(i).set(j, monies);
        }
        else {
            i++;
            j++;
        }
        } while (info.get(i) != null);
    }                                     

    //Exits the program when the "EXIT" button is clicked.
    private void exitMouseClicked(java.awt.event.MouseEvent evt) {                                  
        System.exit(0);
    }                                 
    /**
     * On clicking the "RUN REPORT" button, this calculates the total minutes, 
     * average per hour, total earned to date, and determines if the pay is above,
     * below, or at the minimum wage.
     * @param evt 
     */
    private void reportMouseClicked(java.awt.event.MouseEvent evt) {                                    
        JTextArea writeHere = new JTextArea();
        for (int i = 0; i < info.size(); i++){
            System.out.print(info.get(i));
            System.out.print("\t");
            for (int j = 0; j < info2.size(); j++){
                System.out.print(info2.get(j));
                System.out.println();
            }
        }
        System.out.println("**********************************");
        getTimeSum();
        getMoneySum();
        double average = getMoneySum() / (getTimeSum() / 60);
        System.out.println("The total number of minutes tutored is: " + getTimeSum());
        System.out.printf("\nThe total earned to date is: " + "%.2f", getMoneySum());
        System.out.printf("\nThe average earned per hour is: " + "%.2f", average);
        if (average > minimumWage * 2){
            System.out.println("The rate of pay is currently above average.");
        }
        else if (average >= minimumWage && average <= minimumWage * 2) {
            System.out.println("The rate of pay is average.");
        }
        else System.out.println("The rate of pay is currently below average.");
    }                                   
    private double getTimeSum(){
        double minute = 0;
        double sum = 0;
        for (int i = 0; i < info.size(); i++){
             minute = info.get(i).get(i);
             sum = sum + minute;
             i++;
        }
        return sum;
        
    }
    private double getMoneySum(){
        double total = 0;
        double sum = 0;
        for (int j = 0; j < info.size(); j++){
                 total = info.get(j).get(j);
                 sum = sum + total;
                 j++;
        }
        return sum;
    }
    private void enterMouseClicked(java.awt.event.MouseEvent evt) {                                   
        // TODO add your handling code here:
    }                                  

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        
            
        
        
        
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(tutoringInterface.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                new tutoringInterface().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify                     
    private javax.swing.JButton enter;
    private javax.swing.JButton exit;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JPanel jPanel1;
    private javax.swing.JScrollBar jScrollBar1;
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JTextField min;
    private javax.swing.JTextField mon;
    private javax.swing.JButton report;
    private javax.swing.JTextArea textBox;
    // End of variables declaration                   
}

Can anyone nudge my brain in the right direction to figure this out? I'm thinking something is wrong with

List<Double> test = info.get(i);

Any help would be appreciated.

Thanks.

[Maneesh Godbole]

Welcome to the Ranch!

Exception in thread "AWT-EventQueue-0" java.lang.IndexOutOfBoundsException: Index: 0, Size: 0  

This indicates your array is empty, but you are trying to access the 1st (0 index element)

List<Double> test = info.get(i); 

To solve this, you need to consider a scenario where info might be empty.
In pseudo code
1) Check if info is empty
2) If not, do stuff

[Jayden Brymatt]

Thanks Maneesh! After looking at the rest of my code, I think there are quite a few things that may need enhancing. It all made sense when I was originally typing it, but looking at it a second time shines a new perspective. Thanks for the nudge

[Jayden Brymatt]

So I've got everything working smoothly now, except for one thing. I have to have a couple of exceptions to make sure the minutes entered are greater than 0 and less than 240, and that the earnings entered are greater than 0. Here is my code for this portion, but I keep hanging up:

double minute;
        boolean valid = false;
        do {
            minute = Double.parseDouble(min.getText().toString());
                try {
                    if (minute > 0 || minute <= 240) {
                    info2.add(minute);
                    valid = true;
                    }
                }
                catch (IllegalArgumentException exception) {
                    throw new IllegalArgumentException("Invalid input. Please try again.");
                    
                }
        } while (!valid);

Any reference anyone can point me too on this? I've tried looking around for examples, documentation and reading but I'm just not getting it. Any nudge is appreciated.

[E Armitage]

You have

 Double.parseDouble(min.getText().toString());

outsite the try/catch block. Did you mean to wrap that with the try/catch?

[Jayden Brymatt]

Hi E Armitage, thanks for looking. Yes I meant to wrap that, thanks for the catch! However, even with that I'm getting stuck in an endless loop I think if I enter a value of 0. I changed

if (minute > 0 || minute <= 240)

to

if (minute > 0 && minute <= 240)

due to 0 is always less than 240 and would satisfy one of the parameters.

[Campbell Ritchie]

You should think long and hard about the conditions when you write loops. The number of queries we see about loops which never start or never stop, because people have given them tautologies or contradictions as their loop conditions!

[Winston Gutkowski]

Campbell Ritchie wrote:You should think long and hard about the conditions when you write loops.

@Jayden: you should also not code long lines, especially here.
I'd break yours up myself, but there are tons of them; and it's bad practise.

Winston