Set_Data.java

package cn.web.servlet_context;

import javax.servlet.Servlet;
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;
import java.io.IOException;

@WebServlet("/set_data")
public class Set_Data extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    /*
    ServletContext功能：
       1. 获取MIME类型：

        2. 域对象：共享数据
        3. 获取文件的真实(服务器)路径
     */
        //2. 通过HttpServlet获取
        ServletContext context = this.getServletContext();
        //设置数据
        context.setAttribute("msg", "hehehe");
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doGet(req, resp);
    }
}