cart.java

《jsp网站开发技术》中的源代码(清华大学出版社)

/*
 * Copyright (c) 2000 Javacat. All Rights Reserved.
 *
 * @(#)Cart.java 12/10/2000
 */

package com.javacat.jsp.beans.ebiz;

import javax.servlet.http.*;
import java.util.Vector;
import java.util.Enumeration;
/**
*The Cart bean is used as a dummy cart for client
*to hold their goods when they're shopping online.
*/
public class Cart{
    Vector goods= new Vector();

    String submit = null;
    int ablumID = -1;
    String item=null;
    //add new goods
    private void add(String id) {
    if(!goods.contains(id))
	    goods.addElement(id);
    }
    //remove the specified goods
    private void remove(String[] ids) {
     for(int i=0;i<ids.length;i++){
	       goods.removeElement(ids[i]);
     }
    }

    public void setItem(String id) {
	item = id;
    }

    public void setSubmit(String s) {
    if(s==null||s.equals(""))
      return;
    else submit=s;
    }

    public String[] getAllGoods() {
	String[] sg = new String[goods.size()];
	goods.copyInto(sg);
	return sg;
    }

    public void processRequest(HttpServletRequest request) {
	// null value for submit - user hit enter instead of clicking on
	// "add" or "remove"
	if (submit == null&&request.getParameter("remove")==null){
	    reset();
      return;
  }
	if (submit.equals("add")){
	    add(item);
      this.setAlbumID(item);
  }
	else if (request.getParameter("remove")!=null){
      java.util.Enumeration pns=request.getParameterNames();
	    String pn;
	    String p;
      Vector vid=new Vector();
	    while(pns.hasMoreElements()){
		    pn=(String)pns.nextElement();
		    p=request.getParameter(pn);
        if(pn.startsWith("c")&&p.equals("on")){
          vid.add(pn.substring(1));
        }
      }
      if(vid.size()>0){
      String[] ids=new String[vid.size()];
      vid.copyInto(ids);
	    remove(ids);
      }
  }
	// reset at the end of the request
	reset();
    }

    // reset
    private void reset() {
	submit = null;
	item = null;
    }
    public synchronized void setAlbumID(String ite)
    {
      this.ablumID=Integer.parseInt(ite);
    }
    public synchronized int getAlbumID()
    {
      return this.ablumID;
    }
    public Album[] getOrderedAlbums()
    {
      String[] items=this.getAllGoods();
      Album[] albums=new Album[items.length];
      for(int i=0;i<albums.length;i++)
      {
        albums[i]=new Album(Integer.parseInt(items[i]));
      }
      return albums;
    }
}