addtocarservlet.java

用java+Ajax做的图书商城

package shoppcart;

import java.io.IOException;
import java.io.PrintWriter;

import java.util.ArrayList;

import java.util.Iterator;

import java.util.List;

import javax.servlet.*;
import javax.servlet.http.*;

public class AddToCarServlet extends HttpServlet {
    private static final String CONTENT_TYPE = "text/html; charset=UTF-8";

    public void init(ServletConfig config) throws ServletException {
        super.init(config);
    }

    public void doGet(HttpServletRequest request, 
                      HttpServletResponse response) throws ServletException, IOException {
        response.setContentType(CONTENT_TYPE);
        String id=request.getParameter("id");
        HttpSession session=request.getSession(true);
        ArrayList<BookCount> counts = (ArrayList<BookCount>)session.getAttribute("counts");
        if(counts==null){
            counts = new ArrayList<BookCount>();
            session.setAttribute("counts",counts);
        }        
        
        ArrayList<Product> list = (ArrayList<Product>)session.getAttribute("list");
        if(list==null){
            list = new ArrayList<Product>();
            session.setAttribute("list",list);
            
            Product product=new Product(id);
            list.add(product);
            BookCount bookcount=new BookCount();
            bookcount.setProductID(product.getID());
            bookcount.setCount(1);
            counts.add(bookcount);
        }
        else{
                if(isExist(id,list)){
                    updateProductCount(id,counts);
            }
            else{
                Product product=new Product(id);
                list.add(product);
                BookCount bookcount=new BookCount();
                bookcount.setProductID(product.getID());
                bookcount.setCount(1);
                counts.add(bookcount);
            }
        }
        response.sendRedirect("ShoppingCar.htm");
    }
    private boolean isExist(String id,List<Product>list){
        int listSize=list.size();
        boolean result=false;
        for(int j=0;j<listSize;j++){//鏌ユ壘璐