changeorder.java

书店实现用struts实现的一个系统 采用mysql数据库

/**
 * 该Servlet接受来自myCart.jsp的请求
 * 用于修改用户订单
 */
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
import bean.StrClass;
import bean.CartInf;

public class ChangeOrder extends HttpServlet{
	public void doGet(HttpServletRequest request, HttpServletResponse response)
	throws ServletException, IOException{
		HttpSession session=request.getSession();
		Vector list=(Vector)session.getAttribute("cartList");
   		String errInf=" ";
   		String address="";
   		int n=list.size();
		for(int i=0;i<n;i++) {
			
			/* 判断购物车中哪种图书的数量要修改 */
			CartInf cart=(CartInf)list.elementAt(i);
			String id=cart.getBookId();
			if(request.getParameter(id)!=null) {  
				
				StrClass str = new StrClass(request.getParameter(id));
				if(str.isNum()){
					int num=Integer.parseInt(request.getParameter(id)); 
					if(num==0){
				    	list.removeElementAt(i);   // 如果图书的数量为0,则从购物车中删去该种图书
					} else {
				    	cart.setBookNum(num);      // 更新购物车中该种图书的数量
				    	list.setElementAt(cart,i);
					}
				} else {
					errInf="请在修改预定的数量时输入自然数！";
				}
				break;
			}
		}
		session.removeAttribute("cartList");
    	if(list.size()!=0) {
	    	session.setAttribute("cartList",list);
		}	
        request.setAttribute("errInf",errInf);
		RequestDispatcher dispatcher = 
		                  request.getRequestDispatcher("/myCart.jsp");		            
		dispatcher.forward(request, response);
	}
	public void doPost(HttpServletRequest request, HttpServletResponse response)
	throws ServletException, IOException {
		doGet(request,response);
	}
}