01、ServletContext上下文

 

 

package com.ivan.web;

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;

@WebServlet("/Servlet1")
public class Servlet1 extends HttpServlet{
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // TODO Auto-generated method stub
        ServletContext context = this.getServletContext();
        System.out.println(context);
        context.setAttribute("name", "Ivan it edu studio");
    }
}

package com.ivan.web;

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;

@WebServlet("/Servlet2")
public class Servlet2 extends HttpServlet{
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // TODO Auto-generated method stub
        ServletContext context = this.getServletContext();
        String name = (String)context.getAttribute("name");
        System.out.println(context);
        System.out.println(name);
    }
}

 

@WebServlet("/Servlet3")
public class Servlet3 extends HttpServlet{
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // TODO Auto-generated method stub
        ServletContext context = this.getServletContext();
        context.removeAttribute("name");
    }
}