request实现数据共享的代码

package cn.itcast.servlet.request;

import java.io.BufferedReader;
import java.io.IOException;
import java.util.Enumeration;
import java.util.Map;
import java.util.Set;

import javax.servlet.RequestDispatcher;
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 RequestDemo6
 */
@WebServlet("/requestDemo9")
public class RequestDemo9 extends HttpServlet {
    private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public RequestDemo9() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("demo9被访问了");
        //转发到demo9资源
//        RequestDispatcher requestDispatcher = request.getRequestDispatcher("/requestDemo10");
//        requestDispatcher.forward(request, response);
        
        //在转发之前存储数据到request域中
        request.setAttribute("msg", "hello");
        
        
        request.getRequestDispatcher("/requestDemo10").forward(request, response);
        
        
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doGet(request, response);
    }

}

package cn.itcast.servlet.request;

import java.io.BufferedReader;
import java.io.IOException;
import java.util.Enumeration;
import java.util.Map;
import java.util.Set;

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 RequestDemo6
 */
@WebServlet("/requestDemo10")
public class RequestDemo10 extends HttpServlet {
    private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public RequestDemo10() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //获取数据
        Object msg = request.getAttribute("msg");
        System.out.println(msg);
        
        System.out.println("demo10被访问了");
        
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doGet(request, response);
    }

}