使用MVC+DAO模式完成修改密码功能的完整代码

这是一个简单的基于Java的MVC+DAO模式的修改密码功能的完整代码：

Model类：

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

    public User(String username, String password) {
        this.username = username;
        this.password = password;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getUsername() {
        return username;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getPassword() {
        return password;
    }
}

DAO接口：

public interface UserDAO {
    public boolean updatePassword(User user, String newPassword);
}

DAO实现类：

public class UserDAOImpl implements UserDAO {
    public boolean updatePassword(User user, String newPassword) {
        // 连接数据库
        Connection conn = null;
        PreparedStatement pstmt = null;
        try {
            Class.forName("com.mysql.jdbc.Driver");
            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "123456");
            String sql = "UPDATE user SET password = ? WHERE username = ?";
            pstmt = conn.prepareStatement(sql);
            pstmt.setString(1, newPassword);
            pstmt.setString(2, user.getUsername());
            pstmt.executeUpdate();
            return true;
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
            return false;
        } catch (SQLException e) {
            e.printStackTrace();
            return false;
        } finally {
            try {
                pstmt.close();
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}

Controller类：

public class UserController {
    private UserDAO userDAO;

    public UserController() {
        userDAO = new UserDAOImpl();
    }

    public boolean updatePassword(User user, String newPassword) {
        return userDAO.updatePassword(user, newPassword);
    }
}

View类：

public class ChangePasswordView {
    private UserController userController;

    public ChangePasswordView() {
        userController = new UserController();
    }

    public void onChangePassword(User user, String newPassword) {
        boolean result = userController.updatePassword(user, newPassword);
        if (result) {
            System.out.println("密码修改成功！");
        } else {
            System.out.println("密码修改失败！");
        }
    }
}

使用时，可以这样调用：

User user = new User("example", "oldpassword");
ChangePasswordView view = new ChangePasswordView();
view.onChangePassword(user, "newpassword");

以上就是一个简单的MVC+DAO模式的修改密码功能的完整代码。