additem.java

servlet学习代码

package jsp.servlet.chapter8.session;

import java.io.IOException;
import java.util.List;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import jsp.servlet.util.ServletUtil;

@SuppressWarnings("serial")
public class AddItem extends HttpServlet {
	public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException{
		
		String bookId = request.getParameter("bookId");
		String numStr = request.getParameter(bookId);
		response.setCharacterEncoding("utf-8");
		
		int num = 0;
		try{
			num = Integer.parseInt(numStr);
		}catch(NumberFormatException e){
			response.sendError(response.SC_NOT_FOUND, "订购数量应为数字");
		}
		
		if(num > 0){
			HttpSession session = request.getSession();
			ItemOrder itemOder = new ItemOrder();
			List<CatalogItem> itemList = (List<CatalogItem>) session.getAttribute("itemList");
			for(int i=0; i<itemList.size(); i++){
				CatalogItem item = itemList.get(i);
				if(item.getId().equals(bookId)){
					Cookie customCookie = ServletUtil.getCookie(request, "custom", "");
					String custom = customCookie.getValue();
					Orders oder = (Orders)session.getAttribute(custom);
					if(oder==null){
						oder = new Orders();
					}
					itemOder.setItem(item);
					itemOder.setNumItem(num);
					oder.addItem(itemOder);
					session.setAttribute(custom, oder);
				}
			}
		}
		
		response.sendRedirect("ShopForm");
		
	}
}