我现在有两个问题。我的第一个问题是当我点击确认按钮时，它会将数据插入ms访问数据库两次。我的第二个问题是为什么joptionpane也弹出两次。
打开程序时我有主登录页面。当我单击注册按钮时，它将删除中心jpanel内的所有组件。然后它将再次添加组件用于注册表单，如jtextfield，jlabel，用户名，密码，tel no等图标。我已经检查过，执行insert语句和joptionpanes的语句只有一次。
这是我的程序的完整代码
package userForm;
import java.sql.*;
import java.util.logging.Handler;
import javax.swing.*;
import javax.swing.border.Border;
import javax.swing.border.EmptyBorder;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class loginForm extends JFrame implements ActionListener{
private JPanel centerPanel,bottomPanel;
private JLabel titleLabel, descriptionLabel;
private JLabel usernameLabel, passwordLabel, signInLabel, iconUsername, iconPassword;
private JLabel signUpLabel, fullNameLabel, staffIDLabel, usernameRegLabel, passwordRegLabel, telNoLabel, emailLabel;
private JLabel iconFullName, iconStaffID, iconUsernameReg, iconPasswordReg, iconTelNo, iconEmail;
private JTextField usernameField, fullNameField, staffIDField, usernameRegField, telNoField, emailField;
private JPasswordField passwordField, passwordRegField;
private JButton loginButton, signUpButton,confirmButton,exitButton;
private String username;
private String password;
userDatabase db;
userDatabase db1;
handler handle;
public loginForm(String title) {
db=new userDatabase();
handle =new handler();
//create label to use in topPanel
titleLabel = new JLabel("ABC Burger Inventory System");
titleLabel.setFont(new Font("Calibri", Font.TRUETYPE_FONT, 23));
titleLabel.setForeground(Color.white);
Border empty = new EmptyBorder(30, 20, 0, 0);
titleLabel.setBorder(empty);
descriptionLabel = new JLabel("Please Login To Use This System");
Border empty1 = new EmptyBorder(-30, 20, 0, 0);
descriptionLabel.setBorder(empty1);
descriptionLabel.setFont(new Font("Calibri", Font.HANGING_BASELINE, 14));
descriptionLabel.setForeground(Color.white);
//create label to use in centerPanel
signInLabel = new JLabel("SIGN IN");
usernameLabel = new JLabel("Username:");
passwordLabel = new JLabel("Password");
//create textfield to use in center Panel
usernameField = new JTextField("Required");
passwordField = new JPasswordField("Required");
//create label to use in registration form
signUpLabel = new JLabel("SIGN UP");
fullNameLabel = new JLabel("Full Name:");
staffIDLabel = new JLabel("Staff ID:");
usernameRegLabel = new JLabel("Username:");
passwordRegLabel = new JLabel("Password");
telNoLabel = new JLabel("Tel No:");
emailLabel = new JLabel("Email:");
//create textfield to use in registration form
fullNameField = new JTextField(30);
staffIDField = new JTextField(30);
usernameRegField = new JTextField(30);
passwordRegField = new JPasswordField(30);
telNoField = new JTextField(30);
emailField = new JTextField(30);
//create button to use in bottom Panel
loginButton = new JButton("Login");
signUpButton = new JButton("Sign Up");
confirmButton = new JButton("Confirm");
confirmButton.addActionListener(this);
exitButton = new JButton("Exit");
exitButton.addActionListener(this);
//create panel to use in frame
topPanelWithBackground topPanel = new topPanelWithBackground();
topPanel.setLayout(new GridLayout(2,1));
centerPanel = new JPanel();
centerPanel.setLayout(null);
bottomPanel = new JPanel();
bottomPanel.setLayout(new FlowLayout(FlowLayout.CENTER, 40, 10));
//add component to top panel
topPanel.add(titleLabel);
topPanel.add(descriptionLabel);
//add component to center panel
signInLabel.setBounds(270, 30, 100, 20);
signInLabel.setFont(new Font("Calibri", Font.TRUETYPE_FONT, 20));
centerPanel.add(signInLabel);
usernameLabel.setBounds(200, 60, 100, 20);
usernameLabel.setFont(new Font("Calibri", Font.BOLD, 14));
centerPanel.add(usernameLabel);
ImageIcon imageUser = new ImageIcon("user.png");
iconUsername = new JLabel(imageUser, JLabel.CENTER);
iconUsername.setBounds(160, 90, 32, 32);
centerPanel.add(iconUsername);
usernameField.setBounds(200, 90, 200, 32);
usernameField.setFont(new Font("Calibri", Font.BOLD, 14));
centerPanel.add(usernameField);
passwordLabel.setBounds(200, 140, 100, 20);
passwordLabel.setFont(new Font("Calibri", Font.BOLD, 14));
centerPanel.add(passwordLabel);
ImageIcon imagePassword = new ImageIcon("password.png");
iconUsername = new JLabel(imagePassword, JLabel.CENTER);
iconUsername.setBounds(160, 170, 32, 32);
centerPanel.add(iconUsername);
passwordField.setBounds(200, 170, 200, 32);
passwordField.setFont(new Font("Calibri", Font.BOLD, 14));
centerPanel.add(passwordField);
loginButton.setFont(new Font("Calibri", Font.BOLD, 14));
loginButton.addActionListener(handle);
bottomPanel.add(loginButton);
signUpButton.setFont(new Font("Calibri", Font.BOLD, 14));
signUpButton.addActionListener(this);
bottomPanel.add(signUpButton);
//add confirm button
exitButton.setFont(new Font("Calibri", Font.BOLD, 14));
exitButton.addActionListener(this);
bottomPanel.add(exitButton);
getContentPane().setLayout(new BorderLayout());
getContentPane().add(topPanel, BorderLayout.NORTH );
getContentPane().add(centerPanel, BorderLayout.CENTER);
getContentPane().add(bottomPanel, BorderLayout.SOUTH);
//frame behaviour
super.setTitle(title);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//exit
setSize(600,500);
}
class handler implements ActionListener{
public void actionPerformed(ActionEvent as) {
if(as.getSource()==loginButton){
centerPanel.removeAll();
centerPanel.revalidate();
centerPanel.repaint();
//add component to center panel
signInLabel.setBounds(270, 30, 100, 20);
signInLabel.setFont(new Font("Calibri", Font.TRUETYPE_FONT, 20));
centerPanel.add(signInLabel);
usernameLabel.setBounds(200, 60, 100, 20);
usernameLabel.setFont(new Font("Calibri", Font.BOLD, 14));
centerPanel.add(usernameLabel);
ImageIcon imageUser = new ImageIcon("user.png");
iconUsername = new JLabel(imageUser, JLabel.CENTER);
iconUsername.setBounds(160, 90, 32, 32);
centerPanel.add(iconUsername);
usernameField.setBounds(200, 90, 200, 32);
usernameField.setFont(new Font("Calibri", Font.BOLD, 14));
centerPanel.add(usernameField);
passwordLabel.setBounds(200, 140, 100, 20);
passwordLabel.setFont(new Font("Calibri", Font.BOLD, 14));
centerPanel.add(passwordLabel);
ImageIcon imagePassword = new ImageIcon("password.png");
iconUsername = new JLabel(imagePassword, JLabel.CENTER);
iconUsername.setBounds(160, 170, 32, 32);
centerPanel.add(iconUsername);
passwordField.setBounds(200, 170, 200, 32);
passwordField.setFont(new Font("Calibri", Font.BOLD, 14));
centerPanel.add(passwordField);
char[] temp_pwd=passwordField.getPassword();
String pwd=null;
pwd=String.copyValueOf(temp_pwd);
System.out.println("Username,Pwd:"+usernameField.getText()+","+pwd);
//The entered username and password are sent via "checkLogin()" which return boolean
if(db.checkLogin(usernameField.getText(), pwd))
{
newFrame regFace =new newFrame();
regFace.setVisible(true);
dispose();
}
else if(usernameField.getText().equals("") || passwordField.getText().equals("")){
JOptionPane.showMessageDialog(null, "Please fill out the form","Error!!",
JOptionPane.ERROR_MESSAGE);
}
else
{
//a pop-up box
JOptionPane.showMessageDialog(null, "Login failed!","Failed!!",
JOptionPane.ERROR_MESSAGE);
}
}
}
}
@Override
public void actionPerformed(ActionEvent ae) {
if(ae.getSource()==signUpButton){
centerPanel.removeAll();
//sign up label
signUpLabel.setBounds(270, 30, 100, 20);
signUpLabel.setFont(new Font("Calibri", Font.TRUETYPE_FONT, 20));
centerPanel.add(signUpLabel);
//fullname label,icon and field
fullNameLabel.setBounds(80, 60, 100, 20);
fullNameLabel.setFont(new Font("Calibri", Font.BOLD, 14));
centerPanel.add(fullNameLabel);
ImageIcon imageFullname = new ImageIcon("fullname.png");
iconUsernameReg = new JLabel(imageFullname, JLabel.CENTER);
iconUsernameReg.setBounds(40, 90, 32, 32);
centerPanel.add(iconUsernameReg);
fullNameField.setBounds(80, 90, 200, 32);
fullNameField.setFont(new Font("Calibri", Font.BOLD, 14));
centerPanel.add(fullNameField);
//staffID label,icon and field
staffIDLabel.setBounds(80, 140, 100, 20);
staffIDLabel.setFont(new Font("Calibri", Font.BOLD, 14));
centerPanel.add(staffIDLabel);
ImageIcon imageStaffID = new ImageIcon("staffID.png");
iconStaffID = new JLabel(imageStaffID, JLabel.CENTER);
iconStaffID.setBounds(40, 170, 32, 32);
centerPanel.add(iconStaffID);
staffIDField.setBounds(80, 170, 200, 32);
staffIDField.setFont(new Font("Calibri", Font.BOLD, 14));
centerPanel.add(staffIDField);
//usernameReg label,icon and field
usernameRegLabel.setBounds(80, 220, 100, 20);
usernameRegLabel.setFont(new Font("Calibri", Font.BOLD, 14));
centerPanel.add(usernameRegLabel);
ImageIcon imageUsernameReg = new ImageIcon("user.png");
iconUsernameReg = new JLabel(imageUsernameReg, JLabel.CENTER);
iconUsernameReg.setBounds(40, 250, 32, 32);
centerPanel.add(iconUsernameReg);
usernameRegField.setBounds(80, 250, 200, 32);
usernameRegField.setFont(new Font("Calibri", Font.BOLD, 14));
centerPanel.add(usernameRegField);
//passwordReg label,icon and field
passwordRegLabel.setBounds(350, 60, 100, 20);
passwordRegLabel.setFont(new Font("Calibri", Font.BOLD, 14));
centerPanel.add(passwordRegLabel);
ImageIcon imagePasswordReg = new ImageIcon("password.png");
iconPasswordReg = new JLabel(imagePasswordReg, JLabel.CENTER);
iconPasswordReg.setBounds(310, 90, 32, 32);
centerPanel.add(iconPasswordReg);
passwordRegField.setBounds(350, 90, 200, 32);
passwordRegField.setFont(new Font("Calibri", Font.BOLD, 14));
centerPanel.add(passwordRegField);
//telNo label,icon and field
telNoLabel.setBounds(350, 140, 100, 20);
telNoLabel.setFont(new Font("Calibri", Font.BOLD, 14));
centerPanel.add(telNoLabel);
ImageIcon imagetelNo = new ImageIcon("phone.png");
iconTelNo = new JLabel(imagetelNo, JLabel.CENTER);
iconTelNo.setBounds(310, 170, 32, 32);
centerPanel.add(iconTelNo);
telNoField.setBounds(350, 170, 200, 32);
telNoField.setFont(new Font("Calibri", Font.BOLD, 14));
centerPanel.add(telNoField);
//Email label,icon and field
emailLabel.setBounds(350, 220, 100, 20);
emailLabel.setFont(new Font("Calibri", Font.BOLD, 14));
centerPanel.add(emailLabel);
ImageIcon imageEmail = new ImageIcon("mail.png");
iconEmail = new JLabel(imageEmail , JLabel.CENTER);
iconEmail .setBounds(310, 250, 32, 32);
centerPanel.add(iconEmail );
emailField.setBounds(350, 250, 200, 32);
emailField.setFont(new Font("Calibri", Font.BOLD, 14));
centerPanel.add(emailField);
//add confirm button
confirmButton.setFont(new Font("Calibri", Font.BOLD, 14));
confirmButton.addActionListener(this);
bottomPanel.add(confirmButton);
centerPanel.revalidate();
centerPanel.repaint();
}
else if(ae.getSource()==confirmButton){
char[] temp_pwd1=passwordRegField.getPassword();
String pwd=null;
pwd=String.copyValueOf(temp_pwd1);
if(fullNameField.getText().equals("") || staffIDField.getText().equals("") || usernameRegField.getText().equals("") || passwordRegField.getPassword().length == 0 || telNoField.getText().equals("") || emailField.getText().equals("")){
JOptionPane.showMessageDialog(null, "Please Fill Out Any Field", "Error",
JOptionPane.ERROR_MESSAGE);
}
else {
db1 = new userDatabase();
try {
db1.insertData(fullNameField.getText(), staffIDField.getText(), usernameRegField.getText(), pwd, telNoField.getText(), emailField.getText());
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
else if(ae.getSource()==exitButton){
System.exit(0);
}
}
}
单击注册按钮时，您将再次将侦听器添加到确认按钮。因此，当您单击确认按钮时，它将执行两次。
删除LoginForm的actionPerformed方法中的以下行
confirmButton.addActionListener(this);