Thread: Help with an error in code

I am a newbie to the java world. Can you please assist me by telling me why I am getting this error in my code. I know I am missing something but cant figure it out. The error is in the line when I use :

volumeField.setText(df.format(volume)); The error is df cannot be resolved. I'd appreciate any help that you can give.

import java.awt.Color;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.text.DecimalFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
 
import javax.swing.BorderFactory;
import javax.swing.ButtonGroup;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.JScrollPane;
import javax.swing.JTabbedPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
public class LandScape {
 
	/**
	 * Application starts here.
	 */
	public static void main(String[] args) {
	new LandScape ();
	}
		class Landscape extends JFrame{
			private JTabbedPane tabs;
			private JPanel generalPanel;			
			private JPanel customersPanel;
			private JPanel poolsPanel;
			private JPanel hotTubsPanel;
 
			private void initializeComponents() {
				Container pane = getContentPane();
 
				tabs = new JTabbedPane();
 
				buildGeneralTab();
				buildCustomersTab();
				builPoolsTab();
				buildHotTubsTab();
 
				tabs.add("General", generalPanel);
				tabs.add("Customers", customersPanel);
				tabs.add("Pools", poolsPanel);
				tabs.add("Hot Tubs", hotTubsPanel);
 
				pane.add(tabs);
			}
 
			private void buildHotTubsTab() {
				hotTubsPanel = new JPanel(new FlowLayout());
 
				final JRadioButton roundTub = new JRadioButton("Round Tub");
				final JRadioButton ovalTub = new JRadioButton("Oval Tub");
 
				roundTub.setSelected(true);
 
				ButtonGroup group = new ButtonGroup();
				group.add(roundTub);
				group.add(ovalTub);
 
				hotTubsPanel.add(roundTub);
				hotTubsPanel.add(ovalTub);
 
				hotTubsPanel.add(new JLabel("Enter the tub's length (ft): "));
				final JTextField lengthField = new JTextField(10);
				hotTubsPanel.add(lengthField);
 
				final JLabel widthLabel = new JLabel("Enter the tub's width (ft): ");
				widthLabel.setEnabled(false);
				hotTubsPanel.add(widthLabel);
 
				final JTextField widthField = new JTextField(10);
				widthField.setEnabled(false);
				hotTubsPanel.add(widthField);
 
				hotTubsPanel.add(new JLabel("Enter the tub's depth (ft): "));
				final JTextField depthField = new JTextField(10);
				hotTubsPanel.add(depthField);
 
				JButton calculateVolume = new JButton("Calculate Volume");
				calculateVolume.setMnemonic('C');
				hotTubsPanel.add(calculateVolume);
				hotTubsPanel.add(createExitButton());
 
				hotTubsPanel.add(new JLabel("The tub's volume is (ft^3): "));
				final JTextField volumeField = new JTextField(10);
				volumeField.setEditable(false);
				hotTubsPanel.add(volumeField);
 
				final JTextArea messageArea = createMessageArea(1, 25,
						"Width will be set to the same value as length");
				hotTubsPanel.add(messageArea);
 
				calculateVolume.addActionListener(new ActionListener() {
					public void actionPerformed(ActionEvent e) {
						if (roundTub.isSelected()) {
							widthField.setText(lengthField.getText());
						}
 
						ValidationResult result = validateFields(new JTextField[] {
								lengthField, widthField, depthField });
 
						String errors = "";
						if (result.filled != 3) {
							errors += "Please fill out all fields! ";
						}
						if (result.valid != 3 && result.filled != result.valid) {
							errors += "Please enter valid numbers!";
						}
 
						if (errors != "") {
							messageArea.setText(errors);
							messageArea.setVisible(true);
						} else {
							messageArea.setVisible(false);
 
							double length = Double.parseDouble(lengthField.getText());
							double width = Double.parseDouble(widthField.getText());
							double depth = Double.parseDouble(depthField.getText());
 
							double volume;
							if (roundTub.isSelected()) {
								volume = Math.PI * Math.pow(length / 2.0, 2) * depth;
							} else {
								volume = Math.PI * Math.pow(length * width, 2) * depth;
							}
							volumeField.setText(df.format(volume));
						}
					}
				});
 
				ActionListener tubsListener = new ActionListener() {
					public void actionPerformed(ActionEvent e) {
						if (e.getSource() == roundTub) {
							widthLabel.setEnabled(false);
							widthField.setEnabled(false);
							widthField.setText(lengthField.getText());
							messageArea.setText("Tub's width set to length");
							messageArea.setVisible(true);
						} else if (e.getSource() == ovalTub) {
							widthLabel.setEnabled(true);
							widthField.setEnabled(true);
							messageArea.setVisible(false);
						}
					}
				};
				roundTub.addActionListener(tubsListener);
				ovalTub.addActionListener(tubsListener);
			}
 
			private void builPoolsTab() {
				poolsPanel = new JPanel(new FlowLayout());
 
				poolsPanel.add(new JLabel("Enter the pool's length (ft): "));
				final JTextField lengthField = new JTextField(10);
				poolsPanel.add(lengthField);
 
				poolsPanel.add(new JLabel("Enter the pool's width (ft): "));
				final JTextField widthField = new JTextField(10);
				poolsPanel.add(widthField);
 
				poolsPanel.add(new JLabel("Enter the pool's depth (ft): "));
				final JTextField depthField = new JTextField(10);
				poolsPanel.add(depthField);
 
				JButton calculateVolume = new JButton("Calculate Volume");
				calculateVolume.setMnemonic('C');
				poolsPanel.add(calculateVolume);
				poolsPanel.add(createExitButton());
 
				poolsPanel.add(new JLabel("The pool's volume is (ft^3): "));
				final JTextField volumeField = new JTextField(10);
				volumeField.setEditable(false);
				poolsPanel.add(volumeField);
 
				final JTextArea messageArea = createMessageArea(2, 20, "");
				poolsPanel.add(messageArea);
 
				calculateVolume.addActionListener(new ActionListener() {
					public void actionPerformed(ActionEvent e) {
						ValidationResult result = validateFields(new JTextField[] {
								lengthField, widthField, depthField });
 
						String errors = "";
						if (result.filled != 3) {
							errors += "Please fill out all fields! ";
						}
						if (result.valid != 3 && result.filled != result.valid) {
							errors += "Please enter valid numbers!";
						}
 
						if (errors != "") {
							messageArea.setText(errors);
							messageArea.setVisible(true);
						} else {
							messageArea.setVisible(false);
 
							double length = Double.parseDouble(lengthField.getText());
							double width = Double.parseDouble(widthField.getText());
							double depth = Double.parseDouble(depthField.getText());
 
							double volume = length * width * depth;
 
							volumeField.setText(df.format(volume));
						}
					}
				});
			}
 
 
 
 
 
			private void buildCustomersTab() {
				customersPanel = createContactPanel("Customer", "customer.txt");
			}
 
 
 
 
 
 
			private void buildGeneralTab() {
				generalPanel = new JPanel(new FlowLayout());
				String currentTime = SimpleDateFormat.getInstance().format(
						Calendar.getInstance().getTime());
				generalPanel.add(new JLabel("Today's Date: " + currentTime));
				generalPanel.add(createExitButton());
			}
 
 
			private JButton createExitButton() {
				JButton exitButton = new JButton("Exit");
				exitButton.setMnemonic('x');
				exitButton.addActionListener(new ActionListener() {
					public void actionPerformed(ActionEvent e) {
						System.exit(0);
					}
				});
				return exitButton;
			}
 
 
			@SuppressWarnings("unused")
			private JTextField createTitleField(String text, int length) {
				JTextField tf = new JTextField(length);
				tf.setEditable(false);
				tf.setFocusable(false);
				tf.setText(text);
				return tf;
			}
 
 
			private String loadDataFromFile(String fileName) {
				String data = "";
 
				try {
					BufferedReader reader = new BufferedReader(new FileReader(fileName));
					while (reader.ready()) {
						data += reader.readLine() + "\n";
					}
					reader.close();
				} catch (IOException e) {
				}
 
				return data;
			}
 
 
			private JPanel createContactPanel(final String contactName,
					final String fileName) {
 
				JPanel pane = new JPanel(new FlowLayout());
 
				final JTextArea customerDisplay = new JTextArea(8, 25);
				customerDisplay.setLineWrap(true);
				customerDisplay.setEditable(false);
				pane.add(new JScrollPane(customerDisplay));
 
				pane.add(createExitButton());
 
				JButton addCustomerButton = new JButton("Add " + contactName);
				addCustomerButton.setMnemonic('A');
				pane.add(addCustomerButton);
 
				JButton refreshButton = new JButton("Refresh");
				refreshButton.setMnemonic('R');
				pane.add(refreshButton);
 
				final JTextArea messageArea = createMessageArea(2, 25, "");
				pane.add(messageArea);
 
				addCustomerButton.addActionListener(new ActionListener() {
					public void actionPerformed(ActionEvent e) {
						new EditContact(contactName, fileName);
					}
				});
 
				refreshButton.addActionListener(new ActionListener() {
					public void actionPerformed(ActionEvent e) {
						String data = loadDataFromFile(fileName);
						if (data != "") {
							customerDisplay.setText(data);
							customerDisplay.setEnabled(true);
							messageArea.setText("File " + fileName + " exists "
									+ "and can be read from!");
						} else {
							customerDisplay.setText("Select Add " + contactName
									+ " to add " + contactName.toLowerCase()
									+ "s. Select Refresh to refresh this pane.");
							customerDisplay.setEnabled(false);
							messageArea.setText("File " + fileName + " does not "
									+ "exist yet! Will be created " + "when you add "
									+ contactName.toLowerCase() + "s!");
						}
					}
				});
 
				refreshButton.doClick();
 
				return pane;
			}
 
 
			private JTextArea createMessageArea(int rows, int cols, String text) {
				final JTextArea messageArea = new JTextArea(rows, cols);
				messageArea.setBorder(BorderFactory.createEmptyBorder());
				messageArea.setLineWrap(true);
				messageArea.setWrapStyleWord(true);
				messageArea.setFont(new Font("System", Font.PLAIN, 12));
				messageArea.setText(text);
				messageArea.setBackground(null);
				messageArea.setForeground(Color.red);
				messageArea.setEnabled(true);
				messageArea.setFocusable(false);
				return messageArea;
			}
 
 
			private class ValidationResult {
				/** Number of non-empty fields */
				int filled;
				/** Number of valid fields */
				int valid;
			}
 
 
			private ValidationResult validateFields(JTextField[] fields) {
				ValidationResult result = new ValidationResult();
				for (int i = 0; i < fields.length; i++) {
					JTextField field = fields[i];
					if ((field.getText() != null) && (field.getText().length() > 0)) {
						result.filled++;
					}
					try {
						Double.parseDouble(field.getText());
						field.setBackground(Color.white);
						result.valid++;
					} catch (Exception e) {
						field.setBackground(Color.orange);
					}
				}
				return result;
			}
 
 
			private class EditContact extends JDialog {
				private final String contactName;
				private final String fileName;
				private File file;
 
				private JTextField nameField;
				private JTextField addressField;
				private JTextField cityField;
				private JComboBox stateComboBox;
				private JTextField zipField;
				private JTextField phoneField;
				private JTextArea messageArea;
 
 
				public EditContact(String contactName, String fileName) {
					super(Landscape.this, contactName + "s");
					setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
					setModalityType(ModalityType.APPLICATION_MODAL);
					setSize(400, 300);
					this.contactName = contactName;
					this.fileName = fileName;
 
					initializeComponents();
 
					if (openFile()) {
						displayMessage(null);
					} else {
						displayMessage("File " + fileName + " does not exist yet! "
								+ "Will be created when you add a "
								+ contactName.toLowerCase() + "!");
					}
 
					setLocationRelativeTo(null);
					setVisible(true);
				}
 
				private void displayMessage(String message) {
					if (message != null) {
						messageArea.setVisible(true);
						messageArea.setText(message);
					} else {
						messageArea.setVisible(false);
					}
				}
 
				private boolean openFile() {
					file = new File(fileName);
					return file.exists();
				}
 
				private boolean deleteFile() {
					return file.exists() && file.delete();
				}
 
				private boolean saveToFile() {
					try {
						BufferedWriter writer = new BufferedWriter(new FileWriter(file,
								true));
 
						writer.write("Name: " + nameField.getText() + "\n");
						writer.write("Address: " + addressField.getText() + "\n");
						writer.write("City: " + cityField.getText() + "\n");
						writer.write("State: "
								+ stateComboBox.getSelectedItem().toString() + "\n");
						writer.write("ZIP: " + zipField.getText() + "\n");
						writer.write("Phone: " + phoneField.getText() + "\n");
						writer.write("\n");
 
						writer.close();
						return true;
 
					} catch (IOException e) {
						return false;
					}
				}
 
				private void initializeComponents() {
					Container pane = getContentPane();
					pane.setLayout(new FlowLayout());
 
					pane.add(new JLabel(contactName + " Name "));
					nameField = new JTextField(25);
					pane.add(nameField);
 
					pane.add(new JLabel("Address "));
					addressField = new JTextField(28);
					pane.add(addressField);
 
					pane.add(new JLabel("City "));
					cityField = new JTextField(32);
					pane.add(cityField);
 
					pane.add(new JLabel("State "));
					stateComboBox = new JComboBox(new String[] { "AL", "AK", "AZ",
							"AR", "CA", "CO", "CT", "DE", "FL", "GA", "HI", "ID", "IL",
							"IN", "IA", "KS", "KY", "LA", "ME", "MD", "MA", "MI", "MN",
							"MS", "MO", "MT", "NE", "NV", "NH", "NJ", "NM", "NY", "NC",
							"ND", "OH", "OK", "OR", "PA", "RI", "SC", "SD", "TN", "TX",
							"UT", "VT", "VA", "WA", "WV", "WI", "WY" });
					pane.add(stateComboBox);
 
					pane.add(new JLabel("ZIP "));
					zipField = new JTextField(5);
					pane.add(zipField);
 
					pane.add(new JLabel("Phone "));
					phoneField = new JTextField(10);
					pane.add(phoneField);
 
					JButton addContactButton = new JButton("Add " + this.contactName);
					addContactButton.setMnemonic('A');
					addContactButton.addActionListener(new ActionListener() {
						public void actionPerformed(ActionEvent e) {
							if (saveToFile()) {
								displayMessage(contactName + " added");
							} else {
								displayMessage("File saving error!");
							}
						}
					});
					pane.add(addContactButton);
 
					JButton closeButton = new JButton("Close");
					closeButton.setMnemonic('C');
					closeButton.addActionListener(new ActionListener() {
						public void actionPerformed(ActionEvent e) {
							setVisible(false);
						}
					});
					pane.add(closeButton);
 
					JButton deleteFileButton = new JButton("Delete File");
					deleteFileButton.setMnemonic('D');
					deleteFileButton.addActionListener(new ActionListener() {
						public void actionPerformed(ActionEvent e) {
							if (deleteFile()) {
								displayMessage("File " + fileName + " deleted!");
							}
						}
					});
					pane.add(deleteFileButton);
 
					messageArea = createMessageArea(2, 30, "");
					pane.add(messageArea);
				}
			}
		}}

First of all, this is the Member Introductions forum. You're looking for What's Wrong With My Code? - Java Programming Forums

Also, you never defined df nor did you initialize it.

Even if you did, though I didn't come across it, it's probably lost when it went out of scope if you defined it inside a method.

You probably might have meant depthfield

Thread moved to What's Wrong With My Code?