我正在使用Java Ready 1.4。 我已经提到为从JTextField获取值而发布的代码并尝试了它们，但是我得到了这个compliation错误： 没有名为＆＃34; getText＆＃34;在类型＆＃34; java.lang.String。＆＃34;
中找到我的节目：
import java.awt.*; //for Dimension
import javax.swing.*; //for GUI components
import java.awt.event.*; //for MessageListener
public class MortgageCalculator extends JFrame implements ActionListener
{
public String nameField, ageField, incomeField, priceField, downPayField, interestRateField, paymentField, amortField;
public MortgageCalculator ()
{
//Frame
JFrame frame = new JFrame ();
frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
frame.setSize (new Dimension (300, 250));
frame.setTitle ("Mortgage Calculator");
frame.getContentPane ().setLayout (new BorderLayout ());
//User Information (Input) - Center Panel
JPanel centerPanel = new JPanel (new GridLayout (16, 1));
//Personal Information
centerPanel.add (new JLabel ("Personal Information", SwingConstants.CENTER));
centerPanel.add (new JLabel ("Full Name:"));
final JTextField nameField = new JTextField ();
centerPanel.add (nameField);
centerPanel.add (new JLabel ("Your Age:"));
final JTextField ageField = new JTextField ();
centerPanel.add (ageField);
centerPanel.add (new JLabel ("Yearly Income:"));
final JTextField incomeField = new JTextField ();
centerPanel.add (incomeField);
centerPanel.add (new JLabel ());
//Mortgage Information
centerPanel.add (new JLabel ("Mortgage Information", SwingConstants.CENTER));
centerPanel.add (new JLabel ("Price of Property:"));
final JTextField priceField = new JTextField ();
centerPanel.add (priceField);
centerPanel.add (new JLabel ("Down Payment:"));
final JTextField downPayField = new JTextField ();
centerPanel.add (downPayField);
centerPanel.add (new JLabel ("Interest Rate (%):"));
final JTextField interestRateField = new JTextField ();
centerPanel.add (interestRateField);
centerPanel.add (new JLabel ("Amortization Period (Years):"));
frame.getContentPane ().add (centerPanel, BorderLayout.CENTER);
//User Options (Input) - South Panel
JPanel southPanel = new JPanel (new GridLayout (8, 3));
//Payment Option
southPanel.add (new JLabel ("Payment:"));
southPanel.add (new JLabel ("Type in 1, 2 or 3"));
southPanel.add (new JLabel ());
southPanel.add (new JLabel ("1. Weekly"));
southPanel.add (new JLabel ("2. Biweekly"));
southPanel.add (new JLabel ("3. Monthly"));
final JTextField paymentField = new JTextField ();
southPanel.add (paymentField);
southPanel.add (new JLabel ());
southPanel.add (new JLabel ());
//Amortization Period Option
southPanel.add (new JLabel ("Amortization Period:"));
southPanel.add (new JLabel ("Type in 1, 2 or 3"));
southPanel.add (new JLabel ());
southPanel.add (new JLabel ("1. 20 years"));
southPanel.add (new JLabel ("2. 25 years"));
southPanel.add (new JLabel ("3. 30 years"));
final JTextField amortField = new JTextField ();
southPanel.add (amortField);
southPanel.add (new JLabel ());
southPanel.add (new JLabel ());
//To add a blank line in frame, added three blank JLabels because it is 3 horiontal for grid layout
southPanel.add (new JLabel ());
southPanel.add (new JLabel ());
southPanel.add (new JLabel ());
southPanel.add (new JButton ("Clear Information"));
southPanel.add (new JLabel ());
JButton nextButton = new JButton ("Next");
southPanel.add (nextButton);
frame.getContentPane ().add (southPanel, BorderLayout.SOUTH);
frame.pack ();
frame.setVisible (true);
nextButton.addActionListener (this);
}
public static void main (String[] args)
{
MortgageCalculator mainApp = new MortgageCalculator ();
}
public void actionPerformed (ActionEvent e)
{
//Gets the personal information from the text fields
String name;
int age, payment, amort;
double income, price, downPay, interestRate;
name = nameField.getText ();
age = Integer.parseInt (ageField.getText ());
income = Double.parseDouble (incomeField.getText ());
price = Double.parseDouble (priceField.getText ());
downPay = Double.parseDouble (downPayField.getText ());
interestRate = Double.parseDouble (interestRateField.getText ());
payment = Integer.parseInt (paymentField.getText ());
amort = Integer.parseInt (amortField.getText ());
interestRate = interestRate / 100;
//Output frame
JFrame frame2 = new JFrame ();
frame2.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
frame2.setSize (new Dimension (300, 250));
frame2.setTitle ("Mortgage Calculator");
frame2.getContentPane ().setLayout (new BorderLayout ());
JPanel westPanel2 = new JPanel (new GridLayout (3, 1));
JLabel nameLabel = new JLabel ("Name: " + name);
westPanel2.add (nameLabel);
JLabel ageLabel = new JLabel ("Age: " + age);
westPanel2.add (ageLabel);
JLabel incomeLabel = new JLabel ("Yearly Income: $" + income);
westPanel2.add (incomeLabel);
frame2.getContentPane ().add (westPanel2, BorderLayout.WEST);
JPanel centerPanel2 = new JPanel (new GridLayout (3, 1));
JLabel priceLabel = new JLabel (" Price of property: $" + price);
centerPanel2.add (priceLabel);
JLabel downPayLabel = new JLabel (" Down Payment: $" + downPay);
centerPanel2.add (downPayLabel);
JLabel interestRateLabel = new JLabel (" Interest Rate: " + income);
centerPanel2.add (interestRateLabel);
frame2.getContentPane ().add (centerPanel2, BorderLayout.CENTER);
double interest, numerator, l, denominator, payPerPeriod, initialP, mortgageYearly;
if (payment == 1)
{
interest = 1 + interestRate / 52;
if (amort == 1)
{
l = Math.pow (interest, 20 * 52);
numerator = l * interest;
denominator = l - 1;
initialP = price - downPay;
payPerPeriod = (numerator / denominator) * initialP;
}
else if (amort == 2)
{
l = Math.pow (interest, 25 * 52);
numerator = l * interest;
denominator = l - 1;
initialP = price - downPay;
payPerPeriod = (numerator / denominator) * initialP;
}
else // 3. amort30
{
l = Math.pow (interest, 30 * 52);
numerator = l * interest;
denominator = l - 1;
initialP = price - downPay;
payPerPeriod = (numerator / denominator) * initialP;
}
mortgageYearly = payPerPeriod * 52;
}
else if (payment == 2)
{
interest = 1 + interestRate / 26;
if (amort == 1)
{
l = Math.pow (interest, 20 * 26);
numerator = l * interest;
denominator = l - 1;
initialP = price - downPay;
payPerPeriod = (numerator / denominator) * initialP;
}
else if (amort == 2)
{
l = Math.pow (interest, 25 * 26);
numerator = l * interest;
denominator = l - 1;
initialP = price - downPay;
payPerPeriod = (numerator / denominator) * initialP;
}
else // 3. amort30
{
l = Math.pow (interest, 30 * 26);
numerator = l * interest;
denominator = l - 1;
initialP = price - downPay;
payPerPeriod = (numerator / denominator) * initialP;
}
mortgageYearly = payPerPeriod * 26;
}
else //3. monthly payment
{
interest = 1 + interestRate / 12;
if (amort == 1)
{
l = Math.pow (interest, 20 * 12);
numerator = l * interest;
denominator = l - 1;
initialP = price - downPay;
payPerPeriod = (numerator / denominator) * initialP;
}
else if (amort == 2)
{
l = Math.pow (interest, 25 * 12);
numerator = l * interest;
denominator = l - 1;
initialP = price - downPay;
payPerPeriod = (numerator / denominator) * initialP;
}
else // 2. amort30
{
l = Math.pow (interest, 30 * 12);
numerator = l * interest;
denominator = l - 1;
initialP = price - downPay;
payPerPeriod = (numerator / denominator) * initialP;
}
mortgageYearly = payPerPeriod * 12;
}
JPanel eastPanel2 = new JPanel (new GridLayout (3, 1));
JLabel payTotalLabel = new JLabel (" Payment Total: $" + initialP);
eastPanel2.add (priceLabel);
JLabel payPerPeriodLabel = new JLabel (" Payment per period: $" + payPerPeriod);
eastPanel2.add (payPerPeriodLabel);
frame2.getContentPane ().add (eastPanel2, BorderLayout.EAST);
JPanel southPanel2 = new JPanel (new GridLayout (2, 1));
double minimumIncome = mortgageYearly / 0.28;
JLabel minimumLabel = new JLabel (" Minimum Yearly Income: $" + minimumIncome);
eastPanel2.add (priceLabel);
if (minimumIncome > income)
{
JLabel qualifiedLabel = new JLabel ("You are not qualified for the mortgage");
eastPanel2.add (qualifiedLabel);
}
else
{
JLabel qualifiedLabel = new JLabel ("You are qualified for the mortgage");
eastPanel2.add (qualifiedLabel);
}
frame2.getContentPane ().add (eastPanel2, BorderLayout.EAST);
frame2.pack ();
frame2.setVisible (true);
}
}
答案 0 :(得分：0)
这个错误很简单，但我可以看出它为什么会让你失望。基本上，您的所有field变量（例如nameField和ageField）都定义为班级顶部的String。更改此行中的String：
public String nameField, ageField, incomeField, priceField, downPayField, interestRateField, paymentField, amortField;
致JTextField。然后，在main方法内部，而不是像这样定义每个字段：
final JTextField incomeField = new JTextField（）;
请改为：incomeField = new JTextField ();