JSP+Servlet+Css+Mysql实现网页简单的登录注册功能

以下是实现简单登录注册功能的代码示例。

1. User.java (实体类):

public class User {
    private String username;
    private String password;
 
    // 构造函数、getter和setter省略
}

2. UserDAO.java (数据访问对象):

public class UserDAO {
    public boolean isUserValid(String username, String password) {
        // 连接数据库并验证用户凭据
        // 返回true如果用户有效
    }
 
    public boolean registerUser(User user) {
        // 连接数据库并注册新用户
        // 返回true如果注册成功
    }
}

3. LoginServlet.java (处理登录请求):

@WebServlet("/login")
public class LoginServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String username = request.getParameter("username");
        String password = request.getParameter("password");
 
        UserDAO userDAO = new UserDAO();
        if (userDAO.isUserValid(username, password)) {
            // 登录成功，重定向到主页或其他页面
        } else {
            // 登录失败，返回错误信息或重定向到登录页面
        }
    }
}

4. RegisterServlet.java (处理注册请求):

@WebServlet("/register")
public class RegisterServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String username = request.getParameter("username");
        String password = request.getParameter("password");
 
        User user = new User();
        user.setUsername(username);
        user.setPassword(password);
 
        UserDAO userDAO = new UserDAO();
        if (userDAO.registerUser(user)) {
            // 注册成功，重定向到登录页面
        } else {
            // 注册失败，返回错误信息或重定向到注册页面
        }
    }
}

5. login.jsp (登录页面):

<form action="login" method="post">
    用户名: <input type="text" name="username" /><br />
    密码: <input type="password" name="password" /><br />
    <input type="submit" value="登录" />
</form>

6. register.jsp (注册页面):

<form action="register" method="post">
    用户名: <input type="text" name="username" /><br />
    密码: <input type="password" name="password" /><br />
    <input type="submit" value="