问题：resp cannot be resolved

问题遇到的现象和发生背景

报错提示resp cannot be resolved

问题相关代码，请勿粘贴截图

package note;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Enumeration;

import javax.servlet.GenericServlet;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebServlet;

@WebServlet(description = "TheServlet", urlPatterns = { "/TheServlet" })
public class TheServlet extends GenericServlet {
    public void service(ServletRequest req, ServletResponse res) throws ServletException, IOException {
        ServletContext servletContext = getServletContext(); // 获取Servlet上下文
        resp.setCharacterEncoding("UTF-8");// 设置响应编码类型为UTF-8
        PrintWriter out = res.getWriter(); // 获取输出对象
        out.println("<h2>服务器端信息列表</h2>");
        out.println("<table border='1'>");
        out.println("<tr>");
        out.println("<td>服务器名</td>");
        out.println("<td>" + req.getServerName() + "</td>");
        out.println("</tr>");
        out.println("<tr>");
        out.println("<td>服务器端口号</td>");
        out.println("<td>" + req.getServerPort() + "</td>");
        out.println("</tr>");
        out.println("<tr>");
        out.println("<td>服务器信息</td>");
        out.println("<td>" + servletContext.getServerInfo() + "</td>");
        out.println("</tr>");
        out.println("<tr>");
        out.println("<td>主版本号</td>");
        out.println("<td>" + servletContext.getMajorVersion() + "</td>");
        out.println("</tr>");
        out.println("<tr>");
        out.println("<td>次版本号</td>");
        out.println("<td>" + servletContext.getMinorVersion() + "</td>");
        out.println("</tr>");
        out.println("<tr>");
        out.println("<td>服务器属性</td>");
        Enumeration<String> params = servletContext.getAttributeNames();
        String param = "";
        while (params.hasMoreElements()) {
            param += (String) params.nextElement() + "</br>";
        }
        out.println("<td>" + param + "</td>");
        out.println("</tr>");
        out.println("</table>");
        out.close(); // 关闭输出对象
    }
}

运行结果及报错内容

我想要达到的结果

想要解决这个报错，请问如何解决，毫无头绪

resp cannot be resolved
第18行 resp 改成 res