purchase.java

一个简单的JSP的网络书店系统

package org.pan.web;

import java.util.*;
import java.sql.*;
import java.util.Vector;
import org.pan.util.*;
import javax.servlet.http.*;
import org.pan.web.book.books;
import org.pan.web.book.indentlist;
import org.pan.web.book.indent;

/**
 * Title:        定购图书类
 * Description:
 * Copyright:    Copyright (c) 2008
 * @author:		linlin
 * @version 1.0
 */

public class purchase extends DataBase {
	private javax.servlet.http.HttpServletRequest request; //建立页面请求
	private HttpSession session;				//页面的session;
	private boolean sqlflag = true ;			//对接收到的数据是否正确
	private Vector purchaselist;				//显示图书列表向量数组
	private Vector my_indent;						//订购单列表
	private Vector indent_list;						//订单清单列表
	private int booknumber=0;						//购书总数量
	private float all_price=0;						//购书总价钱
	private boolean isEmpty=false;					//库中的书数量是否够购买的数
	private int leaveBook=0;						//库存数量
	private String IndentNo = "";					//用户订单号
	private boolean isLogin = true;					//用户是否登录！
	private int page = 1;					//显示的页码
	private int pageSize=15;				//每页显示的订单数
	private int pageCount =0;				//页面总数
	private long recordCount =0;			//查询的记录总数
	public String errorMessage = "";  //保存错误信息


	
	public purchase() throws Exception{
		super();
	}

	public Vector getPurchaselist() {
		return purchaselist;
	}

	public Vector getIndent_list() {
		return indent_list;
	}

	public Vector getMy_indent() {
		return my_indent;
	}

	public boolean getSqlflag() {
		return sqlflag;
	}

	public void setIsEmpty(boolean flag){
		isEmpty = flag;
	}
	public boolean getIsEmpty() {
		return isEmpty;
	}

	public void setLeaveBook(int bknum) {
		leaveBook = bknum;
	}
	public int getLeaveBook() {
		return leaveBook;
	}
	
	public void setIndentNo(String newIndentNo) {
		IndentNo = newIndentNo;
	}

	public String getIndentNo() {
		return IndentNo;
	}

	public void setIsLogin(boolean flag){
		isLogin = flag;
	}
	public boolean getIsLogin() {
		return isLogin;
	}

	public int getPage() {				//显示的页码
		return page;
	}
	public void setPage(int newpage) {
		page = newpage;
	}

	public int getPageSize(){			//每页显示的图书数
		return pageSize;
	}
	public void setPageSize(int newpsize) {
		pageSize = newpsize;
	}

	public int getPageCount() {				//页面总数
		return pageCount;
	}
	public void setPageCount(int newpcount) {
		pageCount = newpcount;
	}

	public long getRecordCount() {
		return recordCount;
	}
	public void setRecordCount(long newrcount) {
		recordCount= newrcount;
	}

	public String getGbk( String str) {
		try
		{
			return new String(str.getBytes("ISO8859-1"));
		}
		catch (Exception e)
		{
			return str;
		}
	}
	
  //构造得到图书类别号,图书类别名称的sql语句
	public String getSql() {
		sqlStr = "select id,classname from My_BookClass order by id";
		return sqlStr;
	}

  //根据用户提交的图书编号,数量向购物车中添加信息
	public boolean addnew(HttpServletRequest newrequest){
		request = newrequest;
		String ID = request.getParameter("bookid");
		String Amount = request.getParameter("amount");
		long bookid = 0;
		int amount = 0;
		try
		{
			bookid = Long.parseLong(ID);
			amount = Integer.parseInt(Amount);
		}
		catch (Exception e)
		{
			return false;
		}
		if (amount<1) return false; //用户购买数量必须是正整数
		session = request.getSession(false);
		if (session == null)
		{
			return false;
		}
		purchaselist = (Vector)session.getAttribute("shopcar");
		sqlStr = "select leav_number from My_book where id=" + bookid;
		try
		{
			rs = stmt.executeQuery(sqlStr);
			if (rs.next())
			{
				if (amount > rs.getInt(1)) //如果用户要购买的数量比库存还要大
				{
					leaveBook = rs.getInt(1); //设置库存数量
					isEmpty = true; //设置表示库存中的书不够买
					return false;   //购买失败返回
				}
			}
			rs.close();
		}
		catch (SQLException e)
		{
			return false;
		}

    //如果购买就设置定单的信息(包括图书编号和购买数量)
		indentlist iList = new indentlist();
		iList.setBookNo(bookid);
		iList.setAmount(amount);
		boolean match = false;		//购买车中是否有相同商品,初始化为没有
		if (purchaselist==null)  //第一次向购物车中添加商品
		{
			purchaselist = new Vector(); //所以第一次要构造购物车向量数组
			purchaselist.addElement(iList); //将定单加入到购物车中
		}
		
		else { // 不是第一次向购物车中添加商品		
			//首先在购物车中查询是否有相同的商品,如果有就把数量改变下就行了		
			for (int i=0; i< purchaselist.size(); i++) { 
				indentlist itList= (indentlist) purchaselist.elementAt(i); 
				if ( iList.getBookNo() == itList.getBookNo() ) { 
					itList.setAmount(itList.getAmount() + iList.getAmount()); //如果购买相同的书就把数量增加
					purchaselist.setElementAt(itList,i); //如果购买的是相同的书就修改元素的属性
					match = true; 
					break;
				} //if name matches结束 				
			} // for循环结束 
			if (!match)  //如果是购买车中没有相同商品,就将该定单加入购物车
				purchaselist.addElement(iList); 
		}
		session.setAttribute("shopcar", purchaselist); //将购物车保存到session变量中
		return true;
		
	}

  //修改购物车中图书编号为bookid的购买数量
	public boolean modiShoper(HttpServletRequest newrequest) {
		request = newrequest;
		String ID = request.getParameter("bookid");
		String Amount = request.getParameter("amount");
		long bookid = 0;
		int amount = 0;
		try
		{
			bookid = Long.parseLong(ID);
			amount = Integer.parseInt(Amount);
		}
		catch (Exception e)
		{
			return false;
		}
		if (amount<1) return false;
		session = request.getSession(false);
		if (session == null)
		{
			return false;
		}
		purchaselist = (Vector)session.getAttribute("shopcar");
		if (purchaselist==null)
		{
			return false;
		}
		sqlStr = "select leav_number from My_book where id=" + bookid;
		try
		{
			rs = stmt.executeQuery(sqlStr);
			if (rs.next())
			{
				if (amount > rs.getInt(1))
				{
					leaveBook = rs.getInt(1);
					isEmpty = true;
					return false;
				}
			}
			rs.close();
		}
		catch (SQLException e)
		{
			return false;
		}
		for (int i=0; i< purchaselist.size(); i++) { 
			indentlist itList= (indentlist) purchaselist.elementAt(i); 
			if ( bookid == itList.getBookNo() ) { 
				itList.setAmount(amount); 
				purchaselist.setElementAt(itList,i); 
				break;
			} //if name matches结束 				
		} // for循环结束 
		return true;
	}


  //从购物车中删除图书编号为bookid的定单
	public boolean delShoper(HttpServletRequest newrequest) {
		request = newrequest;
		String ID = request.getParameter("bookid");
		long bookid = 0;
		try
		{
			bookid = Long.parseLong(ID);
		}
		catch (Exception e)
		{
			return false;
		}
		session = request.getSession(false);
		if (session == null)
		{
			return false;
		}
		purchaselist = (Vector)session.getAttribute("shopcar");
		if (purchaselist==null)
		{
			return false;
		}

		for (int i=0; i< purchaselist.size(); i++) { 
			indentlist itList= (indentlist) purchaselist.elementAt(i); 
			if ( bookid == itList.getBookNo() ) { 
				purchaselist.removeElementAt(i); 
				break;
			} //if name matches结束 				
		} // for循环结束 
		return true;
	}

	public boolean payout(HttpServletRequest newrequest) throws Exception {
		request = newrequest;
		session = request.getSession(false);
		if (session == null)
		{