Java 为什么我的JFrame用户名/密码程序声明每次登录都成功？

每当我在用户名/密码字段中输入任何内容时，我总是获得成功。我尝试用一个额外的1来重命名变量，看看问题是不是我意外地使它们彼此相等。我认为情况并非如此。我知道一个简单的程序，但我找不到哪里出错了

package guiPack;

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class LoginFrame extends JFrame implements ActionListener {

    Container container = getContentPane(); // If the code is part of a JFrame, you must use getContentPane
    JLabel userLabel = new JLabel("Username"); // I believe that this part is pretty self-explanatory 
    JLabel passwordLabel = new JLabel("Password");
    JTextField userTextField = new JTextField();
    JPasswordField passwordField = new JPasswordField();
    JButton loginButton = new JButton("LOGIN");
    JCheckBox showPassword = new JCheckBox("Show Password");
    JButton rulesButton = new JButton("Rules");
    JButton createAccButton = new JButton("Register Account");

    LoginFrame() {
        setLayoutManager();
        setLocationAndSize();
        addComponentsToContainer();
        addActionEvent();
    }

    public void setLayoutManager() {
        container.setLayout(null);
    }

    public void setLocationAndSize() {
        userLabel.setBounds(50, 150, 100, 30);
        passwordLabel.setBounds(50, 220, 100, 30);
        userTextField.setBounds(150, 150, 150, 30);
        passwordField.setBounds(150, 220, 150, 30);
        showPassword.setBounds(150, 250, 150, 30);
        loginButton.setBounds(80, 300, 200, 30);
        rulesButton.setBounds(130, 50, 100, 30);
        createAccButton.setBounds(80, 350, 200, 30);    
    }

    public void addComponentsToContainer() {
        container.add(userLabel);
        container.add(passwordLabel);
        container.add(userTextField);
        container.add(passwordField);
        container.add(showPassword);
        container.add(loginButton);
        container.add(rulesButton);
        container.add(createAccButton);
    }

    public void addActionEvent() {
        loginButton.addActionListener(this);
        showPassword.addActionListener(this);
        rulesButton.addActionListener(this);
        createAccButton.addActionListener(this);
    }    

    @Override
    public void actionPerformed(ActionEvent myactionevent) {
        if (myactionevent.getSource() == loginButton) {
            String usernameText;
            // String passwordText; THIS DOES NOT WORK (PART OF THE BELOW COMMENT CODE)
            usernameText = userTextField.getText();
            // passwordText = passwordField.getText(); THIS DOES NOT WORK OR HAS A WARNING BECAUSE THE PASSWORD IS STORED AS A STRING AND IS NOT IN MEMORY. ALTERNATIVE IS USING THE BELOW
            String passwordText=String.valueOf(passwordField.getPassword());
            if (usernameText.equalsIgnoreCase(usernameText) && passwordText.equalsIgnoreCase(passwordText)) // In order to get this part to work you must remove the pre-set password and set it to the string you got from the register below
            {
                JOptionPane.showMessageDialog(this, "Login Successful");
            } 
            
            else 
            {
                JOptionPane.showMessageDialog(this, "Invalid Username or Password");
                userTextField.setText("");
                passwordField.setText("");
            }    
        }
        
        if (myactionevent.getSource() == showPassword) {
            if (showPassword.isSelected()) {
                passwordField.setEchoChar((char) 0);
            } else {
                passwordField.setEchoChar('*'); //this will hide all the characters in the password field
            }
        }
        if (myactionevent.getSource() == rulesButton) {
        //  if (rulesButton.isSelected()) THIS DOES NOT WORK!
            {
                JOptionPane.showMessageDialog(this, "Here are the rules!"
                        + "1. If username and password are correct, success!"
                        +"2. If username and password do not match, incorrect!" + "3. Password must include a special character"); // I am not sure why this is not working. I wanted it to be a row. 
            }
        }
        
        if (myactionevent.getSource() == createAccButton) {
            String usernameText = JOptionPane.showInputDialog("Enter a username!"); // Option to input a username
            String passwordText = JOptionPane.showInputDialog("Enter a password!"); // Option to input a password
        }
    }    
}


    class Login // This is the general windows frame
    {
    public static void main(String[] a) 
    {
        LoginFrame frame = new LoginFrame();
        frame.setTitle("Login Form!");
        frame.setVisible(true);
        frame.setBounds(600, 100, 360, 450);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setResizable(true);

    }
    }

这就是你的问题：

您将usernameText与自身进行比较，而不是与passwordText相同的值进行比较

首先在类中添加硬编码值：

private static final String username="USER";
private static final String password="pAssw0rd";

然后，将该行更改为：

if (username.equals(usernameText) 
  && password.equals(passwordText))

不要在此处使用

equalsIgnoreCase

，如果您使用它，也不要将其用作密码。“密码”与“密码”不同，也不应视为相同

如果您这样做，您将看到，现在您的输入已根据这些字段进行验证，任何其他输入都将导致登录无效

编辑： 关于这一部分：

if (myactionevent.getSource() == createAccButton) // This section of code adds functionality to my Register button
        {
            String usernameText = JOptionPane.showInputDialog("Enter a username!"); // Option to input a username
            String passwordText = JOptionPane.showInputDialog("Enter a password!"); // Option to input a password
        }

这些是局部变量，只存在于这个if块的范围内，所以不能在这个if块之外使用它们

编辑2：

//  if (rulesButton.isSelected()) THIS DOES NOT WORK!

事实上，这很好，但是仅仅因为你点击了一个按钮，并不能使它被选中

---

既然您已经知道该按钮已被单击，您还需要什么？

您如何期望该按钮返回除true以外的任何结果？如果（usernameText.equalsIgnoreCase（usernameText）&&passwordText.equalsIgnoreCase（passwordText）），您的代码确实执行了它应该执行的操作，但没有意义。您正在比较两个字段本身，它们应该通过硬编码值或DB中的值进行比较，或者，更好的是，这些字段的哈希代码应该与DB中的哈希代码进行比较谢谢，我现在明白了，我使用IgnoreCase并将变量=设置为彼此，并期望其他任何东西是多么愚蠢。我忘记了局部变量，也忘记了为什么因为if而不能调用它们block@markinator你能做的就是让JOptionPane设置实例或静态变量，这些是类级别的，所以你可以使用它们；唯一的决赛是permitted@markinator这很可能是因为您将它放在了一个方法中，我希望它位于类级别。在方法中使用private或static确实是不可能的，但在切换到UI编程之前，您应该已经了解了这一点。

//  if (rulesButton.isSelected()) THIS DOES NOT WORK!