我刚刚开始学习Java编程，并且一直在尝试编写一个程序来编写某个空间区域所需的疼痛量。程序运行但清除按钮不起作用。我检查了一切，尝试了一切，但仍然找不到问题。 请帮忙！
// declarations
Color black = new Color(0, 0, 0);
Color white = new Color(255, 255, 255);
Color light_gray = new Color(192, 192, 192);
DecimalFormat currency;
JTextField currencyJTextField;
JLabel roomWidthJLabel;
JTextField roomWidthJTextField;
JLabel roomLengthJLabel;
JTextField roomLengthJTextField;
JLabel numberofGallonsJLabel;
JTextField numberofGallonsJTextField;
JLabel subTotalJLabel;
JTextField subTotalJTextField;
JLabel salesTaxJLabel;
JTextField salesTaxJTextField;
JLabel totalAmountJLabel;
JTextField totalAmountJTextField;
JButton enterJButton;
JButton clearJButton;
double roomWidth;
double roomLength;
double numberofGallons;
double subTotal;
double salesTax;
double totalAmount;
public PaintCalculator()
{
createUserInterface();
}
public void createUserInterface()
{
Container contentPane = getContentPane();
contentPane.setBackground(white);
contentPane.setLayout(null);
// initialize components
// input
roomWidthJLabel = new JLabel ();
roomWidthJLabel.setBounds (50, 20, 150, 20);
roomWidthJLabel.setFont(new Font("Default", Font.PLAIN, 12));
roomWidthJLabel.setText ("Enter Width of Room (Ft):");
roomWidthJLabel.setForeground(black);
roomWidthJLabel.setHorizontalAlignment(JLabel.LEFT);
contentPane.add(roomWidthJLabel);
roomWidthJTextField = new JTextField();
roomWidthJTextField.setBounds(230, 20, 100, 20);
roomWidthJTextField.setFont(new Font("Default", Font.PLAIN, 12));
roomWidthJTextField.setHorizontalAlignment(JTextField.CENTER);
roomWidthJTextField.setForeground(black);
roomWidthJTextField.setBackground(white);
roomWidthJTextField.setEditable(true);
contentPane.add(roomWidthJTextField);
roomLengthJLabel = new JLabel();
roomLengthJLabel.setBounds(50, 70, 150, 20);
roomLengthJLabel.setFont(new Font("Default", Font.PLAIN, 12));
roomLengthJLabel.setText("Enter Length of Room (Ft):");
roomLengthJLabel.setForeground(black);
roomLengthJLabel.setHorizontalAlignment(JLabel.CENTER);
contentPane.add(roomLengthJLabel);
roomLengthJTextField = new JTextField();
roomLengthJTextField.setBounds(230, 70, 100, 20);
roomLengthJTextField.setFont(new Font("Default", Font.PLAIN, 12));
roomLengthJTextField.setHorizontalAlignment(JTextField.CENTER);
roomLengthJTextField.setForeground(black);
roomLengthJTextField.setBackground(white);
roomLengthJTextField.setEditable(true);
contentPane.add(roomLengthJTextField);
// outputs
numberofGallonsJLabel = new JLabel();
numberofGallonsJLabel.setBounds(50, 120, 150, 20);
numberofGallonsJLabel.setFont(new Font("Default", Font.PLAIN, 12));
numberofGallonsJLabel.setText("Number of Gallons:");
numberofGallonsJLabel.setForeground(black);
numberofGallonsJLabel.setHorizontalAlignment(JLabel.LEFT);
contentPane.add(numberofGallonsJLabel);
numberofGallonsJTextField = new JTextField();
numberofGallonsJTextField.setBounds(230, 120, 100, 20);
numberofGallonsJTextField.setFont(new Font("Default", Font.PLAIN, 12));
numberofGallonsJTextField.setHorizontalAlignment(JTextField.CENTER);
numberofGallonsJTextField.setForeground(black);
numberofGallonsJTextField.setBackground(white);
numberofGallonsJTextField.setEditable(false);
contentPane.add(numberofGallonsJTextField);
subTotalJLabel = new JLabel();
subTotalJLabel.setBounds(50, 170, 150, 20);
subTotalJLabel.setFont(new Font("Default", Font.PLAIN, 12));
subTotalJLabel.setText("Sub Total:");
subTotalJLabel.setForeground(black);
subTotalJLabel.setHorizontalAlignment(JLabel.LEFT);
contentPane.add(subTotalJLabel);
subTotalJTextField = new JTextField();
subTotalJTextField.setBounds(230, 170, 100, 20);
subTotalJTextField.setFont(new Font("Default", Font.PLAIN, 12));
subTotalJTextField.setHorizontalAlignment(JTextField.CENTER);
subTotalJTextField.setForeground(black);
subTotalJTextField.setBackground(white);
subTotalJTextField.setEditable(false);
contentPane.add(subTotalJTextField);
salesTaxJLabel = new JLabel();
salesTaxJLabel.setBounds(50, 220, 150, 20);
salesTaxJLabel.setFont(new Font("Default", Font.PLAIN, 12));
salesTaxJLabel.setText("Sales Tax (6%):");
salesTaxJLabel.setForeground(black);
salesTaxJLabel.setHorizontalAlignment(JLabel.LEFT);
contentPane.add(salesTaxJLabel);
salesTaxJTextField = new JTextField();
salesTaxJTextField.setBounds(230, 220, 100, 20);
salesTaxJTextField.setFont(new Font("Default", Font.PLAIN, 12));
salesTaxJTextField.setHorizontalAlignment(JTextField.CENTER);
salesTaxJTextField.setForeground(black);
salesTaxJTextField.setBackground(white);
salesTaxJTextField.setEditable(false);
contentPane.add(salesTaxJTextField);
totalAmountJLabel = new JLabel();
totalAmountJLabel.setBounds(50, 270, 150, 20);
totalAmountJLabel.setFont(new Font("Default", Font.PLAIN, 12));
totalAmountJLabel.setText("Total Sales:");
totalAmountJLabel.setForeground(black);
totalAmountJLabel.setHorizontalAlignment(JLabel.LEFT);
contentPane.add(totalAmountJLabel);
totalAmountJTextField = new JTextField();
totalAmountJTextField.setBounds(230, 270, 100, 20);
totalAmountJTextField.setFont(new Font("Default", Font.PLAIN, 12));
totalAmountJTextField.setHorizontalAlignment(JTextField.CENTER);
totalAmountJTextField.setForeground(black);
totalAmountJTextField.setBackground(white);
totalAmountJTextField.setEditable(false);
contentPane.add(totalAmountJTextField);
// control
enterJButton = new JButton();
enterJButton.setBounds(50, 320, 100, 30);
enterJButton.setFont(new Font("Default", Font.BOLD, 12));
enterJButton.setText("Enter");
enterJButton.setForeground(black);
enterJButton.setBackground(white);
contentPane.add(enterJButton);
enterJButton.addActionListener(
new ActionListener()
{
public void actionPerformed(ActionEvent event)
{
enterJButtonActionPerformed(event);
}
}
);
clearJButton = new JButton();
clearJButton.setBounds(230, 320, 100, 30);
clearJButton.setFont(new Font("Default", Font.BOLD, 12));
clearJButton.setText("Clear");
clearJButton.setForeground(black);
clearJButton.setBackground(white);
contentPane.add(clearJButton);
clearJButton.addActionListener(
new ActionListener()
{
public void actionPerformed(ActionEvent event)
{
enterJButtonActionPerformed(event);
}
}
);
// set properties of application’s window
setTitle("Paint Calculator"); // set title
setSize( 400, 400 ); // set window size
setVisible(true); // display window
}
// main method
public static void main(String[] args)
{
PaintCalculator application = new PaintCalculator();
application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public void enterJButtonActionPerformed(ActionEvent event)
{
getRoomWidthInput();
}
/* Try-Catch Method */
public void getRoomWidthInput()
{
try
{
roomWidth = Double.parseDouble(roomWidthJTextField.getText());
getRoomLengthInput();
}
catch(NumberFormatException exception)
{
JOptionPane.showMessageDialog(this,
"Please enter Room Width!",
"Number Format Error", JOptionPane.ERROR_MESSAGE );
roomWidthJTextField.setText("");
roomWidthJTextField.requestFocusInWindow();
}
}
public void getRoomLengthInput()
{
try
{
roomLength = Double.parseDouble(roomLengthJTextField.getText());
calculateNumberofGallons();
}
catch(NumberFormatException exception)
{
JOptionPane.showMessageDialog(this,
"Please enter Room Length!",
"Number Format Error", JOptionPane.ERROR_MESSAGE );
roomLengthJTextField.setText("");
roomLengthJTextField.requestFocusInWindow();
}
}
public void calculateNumberofGallons()
{ //process data
final double Tax_Rate = .07;
final double priceperGallon = 24.95;
numberofGallons = (roomWidth * roomLength)/ 400;
subTotal = numberofGallons * priceperGallon;
salesTax = subTotal * Tax_Rate;
totalAmount = subTotal + salesTax;
//display results
currency = new DecimalFormat("$0.00");
numberofGallonsJTextField.setText("" + numberofGallons);
subTotalJTextField.setText("" + currency.format(subTotal));
salesTaxJTextField.setText("" + currency.format(salesTax));
totalAmountJTextField.setText("" + currency.format(totalAmount));
}
}