wang2/src/com/mathlearning/util/FileStorage.java

package com.mathlearning.util;

import com.mathlearning.model.User;

import java.io.*;
import java.util.HashMap;
import java.util.Map;

public class FileStorage {
    private static final String USER_DATA_EMAIL_FILE = "users_email.dat";
    private static final String USER_DATA_USERNAME_FILE = "users_username.dat";
    
    @SuppressWarnings("unchecked")
    public static Map<String, User> loadUsersByEmail() {
        try (ObjectInputStream ois = new ObjectInputStream(new FileInputStream(USER_DATA_EMAIL_FILE))) {
            return (Map<String, User>) ois.readObject();
        } catch (FileNotFoundException e) {
            // 文件不存在，返回空Map
            return new HashMap<>();
        } catch (IOException | ClassNotFoundException e) {
            System.err.println("加载用户数据失败: " + e.getMessage());
            return new HashMap<>();
        }
    }
    
    @SuppressWarnings("unchecked")
    public static Map<String, User> loadUsersByUsername() {
        try (ObjectInputStream ois = new ObjectInputStream(new FileInputStream(USER_DATA_USERNAME_FILE))) {
            return (Map<String, User>) ois.readObject();
        } catch (FileNotFoundException e) {
            // 文件不存在，返回空Map
            return new HashMap<>();
        } catch (IOException | ClassNotFoundException e) {
            System.err.println("加载用户数据失败: " + e.getMessage());
            return new HashMap<>();
        }
    }
    
    public static void saveUsers(Map<String, User> usersByEmail, Map<String, User> usersByUsername) {
        try (ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(USER_DATA_EMAIL_FILE))) {
            oos.writeObject(usersByEmail);
        } catch (IOException e) {
            System.err.println("保存用户数据失败: " + e.getMessage());
        }
        
        try (ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(USER_DATA_USERNAME_FILE))) {
            oos.writeObject(usersByUsername);
        } catch (IOException e) {
            System.err.println("保存用户数据失败: " + e.getMessage());
        }
    }
}