Servlet 共享变量

package test.demo1;

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;
import javax.servlet.http.HttpSession;

/**
* Servlet implementation class SetShareVar
*/
@WebServlet("/SetShareVar")
public class SetShareVar extends HttpServlet {
private static final long serialVersionUID = 1L;

/**
* @see HttpServlet#HttpServlet()
*/
public SetShareVar() {
super();
// TODO Auto-generated constructor stub
}

/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub

//设置共享变量
//1.ServletContext
//2.HttpSession
//3.HttpServletRequest

ServletContext ctx=this.getServletContext();
ctx.setAttribute("ctx_name", "ctx_value");

HttpSession session=request.getSession();
session.setAttribute("session_name", "session_value");

request.setAttribute("request_name", "request_value");

request.getRequestDispatcher("GetSharedRequest").forward(request, response);

}

/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}

}

package test.demo1;

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;
import javax.servlet.http.HttpSession;

/**
* Servlet implementation class GetSharedRequest
*/
@WebServlet("/GetSharedRequest")
public class GetSharedRequest extends HttpServlet {
private static final long serialVersionUID = 1L;

/**
* @see HttpServlet#HttpServlet()
*/
public GetSharedRequest() {
super();
// TODO Auto-generated constructor stub
}

/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub

ServletContext ctx=this.getServletContext();
HttpSession session=request.getSession();

String ctx_name=(String)ctx.getAttribute("ctx_name");
String session_name=(String)session.getAttribute("session_name");
String request_name=(String)request.getAttribute("request_name");

System.out.println("ctx:"+ctx_name);
System.out.println("session:"+session_name);
System.out.println("request:"+request_name);

}

/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}

}