jsp购物车 servlet实现的

package shopping; import java.io.IOException; import java.util.StringTokenizer; import java.util.Vector; import javax.servlet.RequestDispatcher; import javax.servlet.ServletConfig; import javax.servlet.ServletContext; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; public class ShoppingServlet extends HttpServlet { public void init(ServletConfig conf)throws ServletException{ super.init(conf); } public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request,response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html;charset=UTF-8"); request.setCharacterEncoding("UTF-8"); HttpSession session=request.getSession(false); if(session==null){ response.sendRedirect("http://localhost:8080/error.html"); } session.putValue("shoppingcart",null); Vector buylist=(Vector)session.getValue("shopping.shoppingcart"); String action =request.getParameter("action"); if(!action.equals("CHECKOUT")){ if(action.equals("DELETE")){ //int d=Integer.parseInt(del); String del=request.getParameter("delindex"); int d=(new Integer(del)).intValue(); buylist.removeElementAt(d); } else if(action.equals("ADD")){ boolean match=false; Books aBook=getBook(request); if(buylist==null){ buylist=new Vector(); buylist.addElement(aBook); } else { for(int i=0;i<buylist.size();i++){ Books book=(Books)buylist.elementAt(i); if(book.getName().equals(aBook.getName())){ book.setQuantity(book.getQuantity()+aBook.getQuantity()); buylist.setElementAt(book, i); match=true; } } if(!match) { buylist.addElement(aBook); } } } session.putValue("shopping.shoppingcart", buylist); String url="/EShop.jsp"; ServletContext sc=getServletContext(); RequestDispatcher rd=sc.getRequestDispatcher(url); rd.forward(request,response); } else if(action.equals("CHECKOUT")){ float total=0; for(int i=0;i<buylist.size();i++){ Books book=(Books)buylist.elementAt(i); float price=book.getPrice(); int qty=book.getQuantity(); total+=(price*qty); } total+=0.005; String amount=String.valueOf(total); int n=amount.indexOf('.'); amount=amount.substring(0,n+3); request.setAttribute("amount", amount); String url="/Checkout.jsp"; ServletContext sc=getServletContext(); RequestDispatcher rd=sc.getRequestDispatcher(url); rd.forward(request, response); } } private Books getBook(HttpServletRequest req){ String myBook=req.getParameter("Book"); String qty=req.getParameter("qty"); StringTokenizer t=new StringTokenizer(myBook,"/"); String artist=t.nextToken(); String name=t.nextToken(); String price=t.nextToken(); Books book=new Books(); book.setArtist(artist); book.setName(name); book.setPrice(Float.parseFloat(price)); book.setQuantity(Integer.parseInt(qty)); return book; } }