student_studying/src/model/User.java

package model;

public class User {
    private String email;
    private String password;
    private String username;

    // 修改构造函数，添加 username 参数
    public User(String email, String password, String username) {
        this.email = email;
        this.password = password;
        this.username = username;
    }

    // 保留原有无参数构造函数，用于旧数据兼容
    public User(String email, String password) {
        this(email, password, email); // 默认用户名为邮箱
    }

    public String getEmail() { return email; }
    public String getPassword() { return password; }
    public String getUsername() { return username; }
}