老师，请检查我的代码？出现500错误

package com.imooc.servletproj;

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet("/SecondServlet")
public class ShopServlet extends HttpServlet{

	@Override
	protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		String name=request.getParameter("category");
		String html = "<h1 style='color:blue'>"+name+"!</h1>";
		  PrintWriter out = response.getWriter(); 
		  out.println(html);
	}
   
}

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  <display-name>SecondServlet</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  
  <servlet>
    <servlet-name>Second</servlet-name>
    <servlet-class>com.imooc.servletproject/SecondServlet</servlet-class>
  </servlet>
  
  <servlet-mapping>
   <servlet-name>Second</servlet-name>
   <url-pattern>/ShopServlet</url-pattern>
   </servlet-mapping>
</web-app>