cartservlet.java

此文件有状态会话Bean 大家体验下合无状态会话Bean的区别

package wyf;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
import javax.naming.*;
import javax.rmi.*;
import javax.ejb.*;


public class CartServlet extends HttpServlet {

	ShoppingCart shoppingCart;

    public void doGet(HttpServletRequest request, HttpServletResponse response) 
                                                throws ServletException, IOException 
    {

		//能处理中文参数乱码问题
		request.setCharacterEncoding("GBK");
        
		//得到参数a的数值
		String action = (String)request.getParameter("a");
		
		System.out.println("---------------------Action------------------------------");
		
		System.out.println(action);
		
		System.out.println("---------------------Action------------------------------");

		HttpSession session = request.getSession(true);
		
		//如果用户不是第一次访问，通过Session让用户使用已有的实例，否则建一个新的
			
        if(session.getAttribute("cart") == null)
        {			 
			try
			{				
				Hashtable<String,String> env = new Hashtable<String,String>();
				env.put(Context.INITIAL_CONTEXT_FACTORY,"weblogic.jndi.WLInitialContextFactory");
				env.put(Context.PROVIDER_URL, "t3://localhost:7001");	
	   		    Context initial = new InitialContext();
	   		    
				shoppingCart=(ShoppingCart)initial.lookup("java:comp/env/ejb/CartRemote");				
	 			session.setAttribute("cart",shoppingCart);
		 	}
		 	catch(Exception ce)
		 	{		    
				ce.printStackTrace();
			}
		}
		else
		{
		    shoppingCart = (ShoppingCart)session.getAttribute("cart");
		}		
                
        //处理各种请求
        if(action.equals("get"))
        {//处理请求购物车的请求
		    //跳转页面
			forward (request,response,"/cart.jsp");
        }
        else if (action.equals("remove")) 
        {//处理删除购物车中商品的请求
		    String id = (String) request.getParameter("id");
            shoppingCart.removeFromCart(id);
			forward(request,response,"/cart.jsp");
        }
        else if(action.equals("add"))
        {//处理往购物车中加商品的请求
			String id = (String) request.getParameter("id");
			String title = (String) request.getParameter("title");
			double price = Double.parseDouble(request.getParameter("price"));
            shoppingCart.addToCart(id,title,price,1);
			forward(request,response,"/video.jsp");
		}
    }


	protected void forward(HttpServletRequest request,HttpServletResponse response,String url)    
	                                                     throws ServletException,IOException 
    {
		RequestDispatcher dispatcher = request.getRequestDispatcher(url);
		dispatcher.forward(request, response);
    }
}