HTML登錄頁面代碼Java

public class LoginServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
private UserDao userDao = new UserDaoImpl();
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String username = request.getParameter("username");
String password = request.getParameter("password");
User user = userDao.getUserByUsernameAndPassword(username, password);
if(user == null) {
response.sendRedirect("login.jsp");
return;
}
HttpSession session = request.getSession();
session.setAttribute("user", user);
response.sendRedirect("index.jsp");
}
}

上述代碼是一個Java Servlet，用來處理HTML登錄頁面的表單提交。在表單提交之前，先獲取頁面傳遞的用戶名和密碼，通過UserDaoImpl來查詢數據庫中是否有匹配的用戶名和密碼。如果匹配不到，就跳轉回登錄頁面；否則，將用戶信息存在session中，同時將頁面跳轉到主頁。