如何在Servlet中使用"应用程序"对象？

import java.io.IOException;
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("/MyServlet")
public class MyServlet extends HttpServlet {

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // 获取ServletContext对象
        ServletContext context = getServletContext();

        // 设置一个属性
        context.setAttribute("myAttribute", "myValue");

        // 获取一个初始化参数
        String myParam = context.getInitParameter("myParam");

        // 输出属性和初始化参数
        response.getWriter().println("My Attribute: " + context.getAttribute("myAttribute"));
        response.getWriter().println("My Param: " + myParam);
    }
}