为啥输出值是null？请老师帮忙检查下

package com.imooc.servlet.context;

import java.io.IOException;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class ServletContextInitServlet
 */
@WebServlet("/context/initcontext")
public class ServletContextInitServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public ServletContextInitServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		ServletContext context= request.getServletContext();
		context.setAttribute("copyright", "©2020 imooc.com All Rights Reserved 京ICP备 12003892号-11");
		context.setAttribute("title", "慕课网，程序员的梦工厂");
		response.getWriter().print("int sccuess");
	}

}

**************************************************************

package com.imooc.servlet.context;

import java.io.IOException;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class ServletContextDefualtServlet
 */
@WebServlet("/context/defulat")
public class ServletContextDefualtServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public ServletContextDefualtServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		ServletContext context= (ServletContext)request.getServletContext();
		String copyright= (String) context.getAttribute("copyright");
		String title = (String) context.getAttribute("title");
		response.setContentType("text/html;charset=utf-8");
		response.getWriter().println("<h1>"+copyright+"</h1>"+title);
		
	}

}