addcartservlet.java

该项目为网上书店

package org.myrose.servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Vector;

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

import org.myrose.beans.BookCart;
import org.myrose.beans.BookInfo;
import org.myrose.dao.BookInfoDAO;

public class AddCartServlet extends HttpServlet {

	/**
	 * Constructor of the object.
	 */
	public AddCartServlet() {
		super();
	}

	/**
	 * Destruction of the servlet. <br>
	 */
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	/**
	 * The doGet method of the servlet. <br>
	 *
	 * 此方法用来添加购物车
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		response.setContentType("text/html;charset=GBK");
		request.setCharacterEncoding("GBK");
		
		String isbn=request.getParameter("ISBN");
		BookInfoDAO dao = new BookInfoDAO();
		
		HttpSession session = request.getSession();
		
		BookInfo b = new BookInfo();
		b.setIsbn(isbn);
		try {
			b = (BookInfo)dao.getBookByIsbn(b);
		} catch (Exception e) {
			e.printStackTrace();
		}
		BookCart bookcart = new BookCart();
		bookcart.setIsbn(isbn);
		bookcart.setPrice(b.getPrice());
		bookcart.setNum(1);
		bookcart.setBookName(b.getBookName());
		boolean flag = true;
		
		Vector cart = (Vector)session.getAttribute("cart");
		if(cart == null){
			cart = new Vector();
		}else{
			for(int i = 0;i < cart.size(); i++){
				BookCart book = (BookCart)cart.elementAt(i);
				if(book.getIsbn().equals(bookcart.getIsbn())){
					book.setNum(book.getNum()+1);
					cart.setElementAt(book, i);
					flag = false;
				}
			}
		}
		if(flag){
			cart.addElement(bookcart);
		}
		session.setAttribute("cart", cart);
		response.sendRedirect("cart_see.jsp");

	}

	/**
	 * The doPost method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to post.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		response.setContentType("text/html;charset=GBK");
		request.setCharacterEncoding("GBK");
		
	}

	/**
	 * Initialization of the servlet. <br>
	 *
	 * @throws ServletException if an error occure
	 */
	public void init() throws ServletException {
		// Put your code here
	}

}