JAVA GUI/JList Question: I cannot get the multiple interval list items to pass and then assign the selected items to a numeric value. (The list items are workshops and the numeric value is the cost of each workshop). I've included the code and bolded the sections that handle the JList data. The program does run, so you can test it if that would help.

Thanks in advance. I've been researching this issue all week and haven't found anything helpful.

Code:

//************************************************************** // Programmer: Jennifer Bailey // CTP 150 - Section 876 // Lab 7 //************************************************************* import javax.swing.*; import java.awt.*; import java.awt.event.*; import javax.swing.event.*; /** This class creates the window for the workshop registration */ public class CRS extends JFrame { //Variables for the description private JLabel description; //Variables for registration type public final double GENERAL = 895.0; //$895 for the general attendant public final double STUDENT = 495.0; //$495 for the student attendant private JRadioButton general; private JRadioButton student; private ButtonGroup attGroup; //radio button group for type of attendant //Variables for optional dinner and speech attendance public final double DINNER = 30.0; //$30 per person cost for the dinner & speeach private JCheckBox dinnerSpeech; //Variables for workshops public final double ECOMMERCE = 295.0; //cost of ecommerce workshop public final double FUTURE_WEB = 295.0; //cost of future of the web workshop public final double JAVA = 395.0; //cost of advanced java workshop public final double NET_SECURITY = 395.0; //cost of network security workshop private JList workshops; private JList selectedWorkshops; String[] seminars = {"Introduction to E-commerce", "The Future of the Web", "Advanced Java Programming", "Network Security"}; //Variables for the buttons private JButton calcButton; // To calculate the total cost private JButton clearButton; //To clear the user selections private JButton exitButton; // To exit the application //Create the panels private JPanel workshopsPanel=new JPanel(); private JPanel descriptPanel= new JPanel(); private JPanel attPanel=new JPanel(); private JPanel dinnerPanel=new JPanel(); private JPanel buttonPanel=new JPanel(); /** Constructor */ public CRS() { //set the title setTitle("Conference Registration System"); //Specify an action for the close button setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //add layout manager setLayout(new BorderLayout()); //build panels buildDescriptPanel(); buildAttPanel(); buildDinnerPanel(); buildWorkshopsPanel(); buildButtonPanel(); //add the panels to the content pane add(descriptPanel, BorderLayout.NORTH); add(buttonPanel, BorderLayout.SOUTH); add(workshopsPanel, BorderLayout.EAST); add(attPanel, BorderLayout.WEST); add(dinnerPanel, BorderLayout.CENTER); //pack and display pack(); setVisible(true); } /** buildDescriptPanel() will create and display a description of the window. */ private void buildDescriptPanel() { //create the label description = new JLabel("Select Registration Options"); //add layout manager descriptPanel.setLayout(new FlowLayout(FlowLayout.CENTER)); //add label to the panel descriptPanel.add(description); } /** buildAttPanel will create and display a radio button option for the user to choose if they're a student or general attendant. */ private void buildAttPanel() { //set window size attPanel.setSize(50, 50); //Create radio buttons general = new JRadioButton("General Registration", true); student = new JRadioButton("Student Registration"); //Group radio buttons attGroup = new ButtonGroup(); attGroup.add(general); attGroup.add(student); //create layout manager attPanel.setLayout(new FlowLayout(FlowLayout.LEFT)); //create a border attPanel.setBorder(BorderFactory.createTitledBorder("Registration Type")); //add radio buttons to the panel attPanel.add(general); attPanel.add(student); } /** The getAttCost method returns the cost for the selected attendant registration. @return attCost One of the constants GENERAL or STUDENT will be returned. */ public double getAttCost() { double attCost = 0.0; if (general.isSelected()) attCost = GENERAL; else if (student.isSelected()) attCost = STUDENT; return attCost; } /** This class will create and display a checkbox option for the user to choose if they want to attend an optional dinner and keynote speech. */ private void buildDinnerPanel() { //create checkbox dinnerSpeech = new JCheckBox("Optional Dinner and Keynote Speech", false); //create a layout manager dinnerPanel.setLayout(new FlowLayout(FlowLayout.LEFT)); //add checkbox to the panel dinnerPanel.add(dinnerSpeech); } /** The getDSCost method returns the cost for the dinner and keynote speech. @return attCost One of the constants GENERAL or STUDENT will be returned. */ public double getDSCost() { double keynoteCost = 0.0; if (dinnerSpeech.isSelected()) keynoteCost = DINNER; else keynoteCost = 0.0; return keynoteCost; } /** buildWorkshopsPanel create and display a list of workshops for the user to choose as many as they want and in any order. */ private void buildWorkshopsPanel() { //create a list workshops = new JList(seminars); //set selection mode workshops.setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION); //set visible rows workshops.setVisibleRowCount(4); //create layout manager workshopsPanel.setLayout(new FlowLayout(FlowLayout.CENTER)); //create a border workshopsPanel.setBorder(BorderFactory.createTitledBorder("Workshops")); //add list to panel workshopsPanel.add(workshops); } /** The getWorkshopCosts will get the total costs for the workshops the user will attend. @return workshopTotal will hold the total costs of the selected workshops */ public double getWorkshopCosts() { String[] selectedWorkshops; double ecommerce; //charges of e-commerce workshop double web; //charges of future of the web workshop double java; //charges of advanced java workshop double security; //charges of network security workshop double workshopTotal = 0.0; //total cost of selected workshops //Get the selected values Object[] selected = workshops.getSelectedValues(); if(selected.equals("Introduction to E-commerce")); ecommerce = ECOMMERCE; ecommerce = 0.0; if(selected.equals("The Future of the Web")); web = FUTURE_WEB; web = 0.0; if(selected.equals("Advanced Java Programming")); java = JAVA; java = 0.0; if(selected.equals("Network Security")); security = NET_SECURITY; security = 0.0; //Get total workshopTotal = ecommerce + web + java + security; return workshopTotal; } /** buildButtonPanel method will create and display the calculate, clear, and exit buttons. */ private void buildButtonPanel() { // Create the buttons calcButton = new JButton("Calculate Charges"); clearButton = new JButton("Clear"); exitButton = new JButton("Exit"); // Add an action listener to the buttons. calcButton.addActionListener(new CalcButtonListener()); clearButton.addActionListener(new ClearButtonListener()); exitButton.addActionListener(new ExitButtonListener()); //add buttons to the panel buttonPanel.add(calcButton); buttonPanel.add(clearButton); buttonPanel.add(exitButton); } /** CalcButton Listener will handle calculating the charges for the event */ private class CalcButtonListener implements ActionListener { /** actionPerformed method @param e An ActionEvent object. */ public void actionPerformed(ActionEvent e) { double totalCost; //Display error message if user hasn't selected an attendant type or workshop if(getAttCost() == 0 || getWorkshopCosts() == 0) JOptionPane.showMessageDialog(null, String.format("Please make sure you've selected a registration type " + "and at least one workshop to attend.")); //calculate the total charge totalCost = getAttCost() + getDSCost() + getWorkshopCosts(); JOptionPane.showMessageDialog(null, String.format("Total Charges: $%,.2f",totalCost)); } } /** ClearButtonListener will handle clearing the info enter by the user when clicked */ private class ClearButtonListener implements ActionListener { /** actionPerformed method @param e An ActionEvent object. */ public void actionPerformed(ActionEvent e) { //write method to set attendant type to default setting attGroup.clearSelection(); //write method to uncheck dinner and speech checkbox dinnerSpeech.setSelected(false); //write method to clear choices on workshop list workshops.removeAll(); //fix this } } /** ExitButtonListener is an action listener class for the exitButton component. */ private class ExitButtonListener implements ActionListener { /** actionPerformed method @param e An ActionEvent object. */ public void actionPerformed(ActionEvent e) { System.exit(0); } } /** The main method creates an instance of the EventCharge class and causes it to display the GUI window. */ public static void main(String[] args) { CRS person1 = new CRS(); } }