以下是一个简单的JSP Servlet用户登录实例的代码:

```java

// UserLoginServlet.java

import java.io.*;

import javax.servlet.*;

import javax.servlet.http.*;

public class UserLoginServlet extends HttpServlet {

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

// 设置响应内容类型

response.setContentType("