使用Integer.parseInt将字符串输入从JTextField转换为Integer，但仍然收到错误消息

• // textSeventh是一个JTextField

• 我正在使用带有动作监听器的提交按钮

String amountInput = textSeventh.getText（）;的System.out.println（amountInput）;

import java.awt.GridBagLayout; import java.awt.GridLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener;

import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.JTextField;

公共类UI2实现ActionListener {

public static void main(String[] args) {
//Dont use the static context. Make an instance variable and call your method.
    UI ui = new UI();
    ui.makeUI();
}

static String questionFirst = "What is your first name?";
static String questionSecond = "What is your last name?";
static String questionThird = "What month were you born? Enter one     number.";
static String questionFourth = "What year were you born?";
static String questionFifth = "What day were you born?";
static String questionSixth = "What is your bank account number";
static String questionSeventh = "How much is in your bank account?   Include decimals.";

public void makeUI() {
    makeBox(questionFirst, questionSecond, questionThird, questionFourth, questionFifth, questionSixth,
        questionSeventh);

}

static JFrame frame = new JFrame("FortuneTeller");
static JPanel panel = new JPanel(new GridBagLayout());

static JLabel labelFirst = new JLabel();
static JTextField textFirst = new JTextField(50);

static JLabel labelSecond = new JLabel();
static JTextField textSecond = new JTextField(50);

static JLabel labelThird = new JLabel();
static JTextField textThird = new JTextField(50);

static JLabel labelFourth = new JLabel();
static JTextField textFourth = new JTextField(50);

static JLabel labelFifth = new JLabel();
static JTextField textFifth = new JTextField(50);

static JLabel labelSixth = new JLabel();
static JTextField textSixth = new JTextField(50);

static JLabel labelSeventh = new JLabel();
static JTextField textSeventh = new JTextField(50);

static JButton submitButton = new JButton("Submit");

static String firstName;
static String lastName;
static String month;
static String year;
static String day;
static String bankNum;
static String amount;

static char favoriteLetter;
static String both;
static String reverse;
static String favoritePalindrome;
static String favoriteColor; // red or blue
static String favoriteAnimal; // cat or dog
static String favoriteCar; // F150 or Minivan
static String favoriteNum;
static int intDollars;
static String math;

public void makeBox（String questionFirst，String questionSecond，String questionThird，String questionFourth，String questionFifth，String questionSixth，String questionSeventh）{frame.add（panel）; frame.setVisible（真）; frame.setSize（700,200）; frame.setDefaultCloseOperation（JFrame.EXIT_ON_CLOSE）; panel.setLayout（new GridLayout（8,1））; //现在我只是尝试从第一个box panel.add（labelFirst）获取输入; labelFirst.setText（questionFirst）; panel.add（textFirst）;

// This is the advice from my school's computer science teacher when we thought
// that
// the program was printing the initial value inside the textfield, nothing.
// Enter text
// Wait for submit button
// Then getText();
// I was still unable to get it to work

panel.add(labelSecond);
labelSecond.setText(questionSecond);
panel.add(textSecond);

//get text will be empty here. You should be calling this after the user enters text and clicks submit.
lastName = textSecond.getText();

panel.add(labelThird);
labelThird.setText(questionThird);
panel.add(textThird);

//get text will be empty here. You should be calling this after the user enters text and clicks submit.
month = textThird.getText();

panel.add(labelFourth);
labelFourth.setText(questionFourth);
panel.add(textFourth);

//get text will be empty here. You should be calling this after the user enters text and clicks submit.
year = textFourth.getText();

panel.add(labelFifth);
labelFifth.setText(questionFifth);
panel.add(textFifth);

//get text will be empty here. You should be calling this after the user enters text and clicks submit.
day = textFifth.getText();

panel.add(labelSixth);
labelSixth.setText(questionSixth);
panel.add(textSixth);
//get text will be empty here. You should be calling this after the user enters text and clicks submit.
bankNum = textSixth.getText();

panel.add(labelSeventh);
labelSeventh.setText(questionSeventh);
panel.add(textSeventh);
//get text will be empty here. You should be calling this after the user enters text and clicks submit.
amount = textSeventh.getText();

//need to add an actionListener to the button
submitButton.addActionListener(this);

panel.add(submitButton);
frame.pack();

}

@Override public void actionPerformed（ActionEvent e）{

// TODO Auto-generated method stub

//You need to get the source of the button. (JButton) e.getSource();
JButton buttonPressed = (JButton) e.getSource();
if (buttonPressed == submitButton) {
    String firstNameInput = textFirst.getText();
    System.out.println(firstNameInput);
}

}}