public class LoginServlet extends HttpServlet { @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //处理POST请求 String username = request.getParameter("username"); String password = request.getParameter("password"); boolean rememberMe = "on".equals(request.getParameter("remember-me")); try { if (username != null && !username.trim().isEmpty() && password != null && !password.trim().isEmpty()) { String hashedPasswd = hashPassword(password); if (authenticate(username, hashedPasswd)) { HttpSession session = request.getSession(); session.setAttribute("username", username); response.sendRedirect("mean1"); } else { response.sendRedirect("/login.html?error=1"); } } else { response.sendRedirect("/login.html?error=2"); } } catch (SQLException e) { throw new ServletException("Cannot connect to DB", e); } catch (NoSuchAlgorithmException e) { throw new ServletException("Cannot encrypt password", e); }如何修改代码，将其变为根据两个不同用户进入两个不同的页面代码

可以在 `authenticate()` 方法中增加根据用户名判断跳转到不同页面的逻辑，具体代码如下：

public class LoginServlet extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //处理POST请求
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        boolean rememberMe = "on".equals(request.getParameter("remember-me"));
        try {
            if (username != null && !username.trim().isEmpty() &&
                    password != null && !password.trim().isEmpty()) {
                String hashedPasswd = hashPassword(password);
                if (authenticate(username, hashedPasswd)) {
                    HttpSession session = request.getSession();
                    session.setAttribute("username", username);
                    if (username.equals("user1")) {
                        response.sendRedirect("page1.jsp");
                    } else if (username.equals("user2")) {
                        response.sendRedirect("page2.jsp");
                    } else {
                        response.sendRedirect("default.jsp");
                    }
                } else {
                    response.sendRedirect("/login.html?error=1");
                }
            } else {
                response.sendRedirect("/login.html?error=2");
            }
        } catch (SQLException e) {
            throw new ServletException("Cannot connect to DB", e);
        } catch (NoSuchAlgorithmException e) {
            throw new ServletException("Cannot encrypt password", e);
        }
    }
}

在上述代码中，我们增加了根据用户名判断跳转到不同页面的逻辑。当用户名为 `user1` 时，跳转到 `page1.jsp` 页面；当用户名为 `user2` 时，跳转到 `page2.jsp` 页面；否则跳转到 `default.jsp` 页面。您需要根据实际需求修改页面名称和判断逻辑。