基于javaweb+mysql的jsp+servlet旅游管理系统(java+jsp+html+bootstrap+servlet+mysql)

// UserServlet.java
@WebServlet("/user")
public class UserServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String action = request.getParameter("action");
        if ("login".equals(action)) {
            String username = request.getParameter("username");
            String password = request.getParameter("password");
            User user = UserService.login(username, password);
            if (user != null) {
                // 登录成功，保存用户信息到session并重定向到主页
                request.getSession().setAttribute("user", user);
                response.sendRedirect("index.jsp");
            } else {
                // 登录失败，保存错误信息到request属性并跳转回登录页面
                request.setAttribute("error", "登录失败，用户名或密码错误");
                request.getRequestDispatcher("login.jsp").forward(request, response);
            }
        }
    }
}

// UserService.java
public class UserService {
    public static User login(String username, String password) {
        // 这里应该是对数据库的查询操作，假设已经有了User对象
        // User user = queryDatabase(username, password);
        User user = null; // 假设没有找到用户
        if ("admin".equals(username) && "password".equals(password)) {
            user = new User();
            user.setUsername(username);
            // 设置其他用户信息...
        }
        return user;
    }
}

// User.java
public class User {
    private String username;
    // 其他用户信息...

    // getter和setter方法...
}

// login.jsp
<form action="user?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>

<c:if test="${not empty error}">
    <p style="color: red">${error}</p>
</c:if>