下面是一个简单的Servlet和JSP实现登录功能的例子。
创建一个名为`LoginServlet.java`的Servlet类:

```java
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.IOException;
public class LoginServlet extends HttpServlet {
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 获取用户名和密码
String username = request.getParameter("









