java - 如何解决我的登录/创建帐户程序中的这个序列化错误？

Question

我正在编写一个简单的 GUI 程序，它使用文本文件中的登录信息。它从另一个创建用户帐户的 GUI 程序获取登录信息。我不确定如何轻松有效地序列化它，因为这只是我最近学到的东西。我应该怎么办？我该如何解决这个序列化错误，我可以做些什么来改进它并使其发挥作用。

用户类:

package passwordProgram;

import java.util.ArrayList;
import java.util.Arrays;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import java.io.Serializable;

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

public class User implements Serializable, ActionListener {

    public static ArrayList<String> allUsernames = new ArrayList<String>();

    String username;
    String password;

    public static void main(String[] args) {
        try {
            UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
        } catch (Exception e) {
            e.printStackTrace();
        }
        User user = new User();
        user.mainGUI();
    }



    JFrame frame;
    JPanel panel;
    JTextField createUsername;
    JPasswordField createPassword;
    JPasswordField confirmPassword;
    JButton createAccount;
    JLabel noValid;

    public void mainGUI() {
        noValid = new JLabel();
        frame = new JFrame("Create a new account!");
        panel = new JPanel();
        panel.setBackground(Color.ORANGE);
        createPassword = new JPasswordField(10);
        confirmPassword = new JPasswordField(10);
        createUsername = new JTextField(10);
        JLabel userTxt = new JLabel("New Username: ");
        JLabel userPass = new JLabel("New Password: ");
        JLabel confirmPass = new JLabel("Confirm Password: ");
        createAccount = new JButton("Create your account!");

        panel.setLayout(new GridBagLayout());
        GridBagConstraints left = new GridBagConstraints();
        left.anchor = GridBagConstraints.WEST;
        GridBagConstraints right = new GridBagConstraints();
        right.anchor = GridBagConstraints.EAST;
        right.weightx = 2.0;
        right.fill = GridBagConstraints.HORIZONTAL;
        right.gridwidth = GridBagConstraints.REMAINDER;

        frame.getContentPane().add(BorderLayout.NORTH, noValid);
        frame.getContentPane().add(BorderLayout.CENTER, panel);
        panel.add(userTxt, left);
        panel.add(createUsername, right);
        panel.add(userPass, left);
        panel.add(createPassword, right);
        panel.add(confirmPass, left);
        panel.add(confirmPassword, right);

        frame.getContentPane().add(BorderLayout.SOUTH, createAccount);
        frame.setVisible(true);
        frame.setSize(500, 300);

        createAccount.addActionListener(this);
    }

    public void actionPerformed(ActionEvent event) {
        if (createUsername.getText().length() <= 0 ) {
            noValid.setText("That is not a valid username. Please try again.");
            frame.getContentPane().add(BorderLayout.NORTH, noValid);
        }

        else if (allUsernames.contains(createUsername.getText())) {
            noValid.setText("That username is already taken. Please try again.");
            frame.getContentPane().add(BorderLayout.NORTH, noValid);
        }

        else if (!(Arrays.equals(createPassword.getPassword(), confirmPassword.getPassword()))) {
            noValid.setText("Your passwords do not match!");
            frame.getContentPane().add(BorderLayout.NORTH, noValid);
        } else {    
            SaveUser sUser = new SaveUser();
            sUser.createAccount(this);
            noValid.setText("Account created successfully");
            frame.getContentPane().add(BorderLayout.NORTH, noValid);
        }
    }
}

SaveUser类(序列化)

package passwordProgram;

import java.io.FileOutputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

public class SaveUser implements Serializable{
    public void createAccount(User u) {
        try {
            FileOutputStream fileOS = new FileOutputStream("userInfo.ser");
            ObjectOutputStream objectOS = new ObjectOutputStream(fileOS);
            objectOS.writeObject(u);
            objectOS.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

这是我在尝试运行 User 类时遇到的错误。

java.io.NotSerializableException: passwordProgram.User
    at java.io.ObjectOutputStream.writeObject0(Unknown Source)
    at java.io.ObjectOutputStream.writeObject(Unknown Source)
    at passwordProgram.SaveUser.createAccount(SaveUser.java:12)
    at passwordProgram.User.actionPerformed(User.java:104)
    at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
    at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
    at javax.swing.AbstractButton.doClick(Unknown Source)
    at javax.swing.plaf.basic.BasicRootPaneUI$Actions.actionPerformed(Unknown Source)
    at javax.swing.SwingUtilities.notifyAction(Unknown Source)
    at javax.swing.JComponent.processKeyBinding(Unknown Source)
    at javax.swing.KeyboardManager.fireBinding(Unknown Source)
    at javax.swing.KeyboardManager.fireKeyboardAction(Unknown Source)
    at javax.swing.JComponent.processKeyBindingsForAllComponents(Unknown Source)
    at javax.swing.JComponent.processKeyBindings(Unknown Source)
    at javax.swing.JComponent.processKeyEvent(Unknown Source)
    at java.awt.Component.processEvent(Unknown Source)
    at java.awt.Container.processEvent(Unknown Source)
    at java.awt.Component.dispatchEventImpl(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.KeyboardFocusManager.redispatchEvent(Unknown Source)
    at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(Unknown Source)
    at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(Unknown Source)
    at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(Unknown Source)
    at java.awt.DefaultKeyboardFocusManager.dispatchEvent(Unknown Source)
    at java.awt.Component.dispatchEventImpl(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Window.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
    at java.awt.EventQueue.access$000(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue$4.run(Unknown Source)
    at java.awt.EventQueue$4.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue.dispatchEvent(Unknown Source)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.run(Unknown Source)

这是我的类登录:

封装密码程序；

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.FileInputStream;
import java.io.ObjectInputStream;

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


public class LogInScreen implements ActionListener {


    public static void main(String[] args) {
        try {
        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
        } 
        catch (Exception e) {
        }
        LogInScreen logger = new LogInScreen();
        logger.start();
    }

Answer 1

就我个人而言，我认为对象序列化在这种情况下已经结束了。

您可以简单地将详细信息写入文本文件...

public TestFileIO() {
    try {
        writeUser(new File("User.inf"), "Test", "Password".toCharArray());
    } catch (IOException ex) {
        ex.printStackTrace();
    }
}

public void writeUser(File file, String name, char[] password) throws IOException {
    BufferedWriter bw = null;
    try {
        bw = new BufferedWriter(new FileWriter(file));
        bw.write(name);
        bw.newLine();
        bw.write(password);
        bw.flush();
    } finally {
        try {
            bw.close();
        } catch (Exception e) {
        }
    }
}

这将简单地将用户名和密码写入文件，并用新行分隔。

如果您在文件中需要不止一个用户，您可以简单地将用户名密码写在同一行上，使用预定义的分隔符...

public TestFileIO() {
    try {
        writeUser(new File("User.inf"), "Test", "Password".toCharArray());
    } catch (IOException ex) {
        ex.printStackTrace();
    }
}

public void writeUser(File file, String name, char[] password) throws IOException {
    BufferedWriter bw = null;
    try {
        bw = new BufferedWriter(new FileWriter(file));
        bw.write(name);
        bw.write(";");
        bw.write(password);
        bw.flush();
    } finally {
        try {
            bw.close();
        } catch (Exception e) {
        }
    }
}

现在，如果您担心将密码保存为纯文本，您可以(个人世界)将密码保存为 MD5 哈希...

public TestFileIO() {
    try {
        writeUser(new File("User.inf"), "Test", "Password".toCharArray());
    } catch (Exception ex) {
        ex.printStackTrace();
    }
}

public void writeUser(File file, String name, char[] password) throws IOException, NoSuchAlgorithmException {

    BufferedWriter bw = null;

    try {
        MessageDigest md = MessageDigest.getInstance("MD5");
        byte[] bytes = new byte[password.length];
        for (int i = 0; i < bytes.length; i++) {
            bytes[i] = (byte) password[i];
        }
        md.update(bytes);
        byte[] mdbytes = md.digest();

        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < mdbytes.length; i++) {
            sb.append(Integer.toString((mdbytes[i] & 0xff) + 0x100, 16).substring(1));
        }

        bw = new BufferedWriter(new FileWriter(file));
        bw.write(name);
        bw.newLine();
        bw.write(sb.toString());
        bw.flush();
    } finally {
        try {
            bw.close();
        } catch (Exception e) {
        }
    }
}