bagbean.java

网上书店 一个在线购物的完整例子-网上书店JSP系统。

package com.bitc.store;
//定义Bean所属的套件

//指定欲使用的套件
import java.sql.*;
import java.util.Date;

public class BagBean
{
	private String BookList = "";	
	//起始设定BookList属性

	public BagBean()  //建构子
	{ }		

	//以下为设定Bean的方法	

	//判断BookList中是否有资料, 是则代表购物袋中有购买的书籍
	public boolean HaveBook() 
	{ 
		boolean result = false;

		if (!BookList.equals(""))
			result = true; 

		return result;			
	}

	//清除购物袋
	public void ClearBag ()
	{ 
		BookList  = "";
	}

	//判断某书籍是否已置入购物袋
	public boolean InBag(String BookID)
	{ 
		boolean result = true;

		if(BookList.indexOf(BookID) == -1)
			result = false;		
		
		return result;
	}
	
	//取得某书籍的订购数量
	public String getQty(String BookID)
	{ 
		String result = null;
		int index = 0, start = 0, end = 0;
		
		index = BookList.indexOf(BookID);
			
		if(index != -1)
		{
			start = BookList.indexOf(':', index);
			end = BookList.indexOf('&', index);

			result = BookList.substring(start + 1, end);			
		}		
		
		return result;
	}
	
	//将预定订购的书籍与数量置入购物袋
	public void AddBook(String BookID, String Qty)
	{ 
		BookList = BookList + BookID + ":" + Qty + "&";
	}
	
	//设定某书籍的购买数量
	public void setQty(String BookID, String Qty)
	{ 
		int index = 0;
				
		index = BookList.indexOf(BookID);
		//寻找某书籍在BookList字串中的位置

		if(index != -1)
		{
			String str1 = "", str2 = "";
			int start = BookList.indexOf(':', index);
			int end = BookList.indexOf('&', index);
			//寻找 : 与 & 符号的位置, 找出原储存价格资料的位置

			str1 = BookList.substring(0, start - 1);
			str2 = BookList.substring(end);
			BookList = str1 + Qty + str2;
			//将新价格置入BookList
		}		
	}

	//与资料库连结有关的Bean属性
	Connection con = null;
	Statement stmt = null;
	ResultSet BagRs = null;

	//起始取得购物袋中已选购书籍的查询字串
	public void InitBagRs(Connection con)
	{
		if(this.con != con)
			this.con = con;

		String BookID = BookID(); 
		//取得购物袋中所有订购书籍的编号		
		
		try{
			stmt = con.createStatement(
					ResultSet.TYPE_SCROLL_INSENSITIVE,
					ResultSet.CONCUR_READ_ONLY);
			//建立Statement物件		
			
			String strSQL = "SELECT * FROM Book " + 
				"WHERE BookID IN (" +	BookID + ")";
			//建立SQL字串

			BagRs = stmt.executeQuery(strSQL);
			//执行SQL叙述
		}
		catch(SQLException sex)
		{
			System.out.println(sex.toString());
		}						
	}

	//关闭ResultSet物件与Statement物件
	public void CloseBagRs ()
	{ 
		try{
			if(BagRs != null)
			{
				BagRs.close();				
				BagRs = null;
			}

			if(stmt != null)
			{
				stmt.close();
				stmt = null;
			}
		}
		catch(SQLException sex)
		{
			System.out.println(sex.toString());
		}
	}

	//将ResultSet物件的指标向後移动
	public boolean next()
	{ 
		boolean result = false;

		try{
			result = BagRs.next();
		}
		catch(SQLException sex)
		{
			System.out.println(sex.toString());
		}
		return result;
	}
	
	//取得记录集中的ID栏位
	public String getBookID()
	{ 
		String result = null;
		try{
			result = BagRs.getString("BookID");
		}
		catch(SQLException sex)
		{
			System.out.println(sex.toString());
		}		
		return result;
	}

	//取得记录集中的BookNm栏位
	public String getBookNm()
	{ 
		String result = null;
		try{
			result = BagRs.getString("BookNm");
		}
		catch(SQLException sex)
		{
			System.out.println(sex.toString());
		}		
		return result;
	}
	
	//取得记录集中的Price栏位
	public double getPrice()
	{ 
		double result = 0.0;
		try{
			result = BagRs.getDouble("Price");
		}
		catch(SQLException sex)
		{
			System.out.println(sex.toString());
		}		
		return result;
	}

	//将订单资料新增至资料库中
	public void InsertOrder(Connection con, String Name, 
				String Address, String Phone, String E_Mail)
	{
		if(this.con != con)
			this.con = con;

		String BookID = BookID(); 
		//取得购物袋中所有订购书籍的编号
		
		try{
			String Time = Now();

			stmt = con.createStatement(
					ResultSet.TYPE_SCROLL_INSENSITIVE,
					ResultSet.CONCUR_READ_ONLY);
			//建立Statement物件		
			
			String strSQL = "INSERT INTO BookOrder " + 
			       "(OrderTime, Name, Phone, E_Mail, Address)" + 
			       " VALUES ('" + Time + "','" + Name + "','" + 
			       Phone  + "','" + E_Mail + "','" + Address + "')";
			//建立将资料新增至资料库的SQL叙述

			stmt.executeUpdate(strSQL); //执行SQL叙述
		
			strSQL = "SELECT ID FROM BookOrder " + 
				 "WHERE OrderTime = '" + Time + "'";
			//从BookOrder资料表取得上次新增资料的SQL叙述

			ResultSet IDRs = stmt.executeQuery(strSQL);
			//执行SQL叙述取得ResultSet物件

			IDRs.next(); //移至第一笔记录

			String OrdID = IDRs.getString("ID");
			//取得ID栏位
		
			IDRs.close(); //关闭ResultSet物件
	
			int num = 0, i = 0, end = 0, start = 0;
			
			end = BookList.indexOf(':'); 
			//在BookList字串中寻找':'字元
			
			//利用while回圈将BookList中的书籍编号串接成BookID字串		
			while(end != -1)
			{
				String BID = BookList.substring(start, end);

				strSQL = "INSERT INTO OrderDetail " +
     				  "(OrderID, BookID, Quity) VALUES " +
				  "(" + OrdID + ",'" + BID + "'," + 
				  getQty(BID) + ")";
				//建立将订购明细资料新增至OrderDetail资料表的SQL叙述
			
				stmt.executeUpdate(strSQL);
				//执行新增订购明细资料的SQL叙述			
				
				end = BookList.indexOf(':', end + 1);			
				start = BookList.indexOf('&', start);
				start = start + 1;			
			}		
		}
		catch(SQLException sex)
		{
			System.out.println(sex.toString());
		}
		
	}

	//建立符合资料库格式要求的系统时间
	public String Now()
	{
		Date Now = new Date(); //取得目前的系统时间
		String year = String.valueOf(Now.getYear() + 1900);
		String month = String.valueOf(Now.getMonth() + 1);
		String day = String.valueOf(Now.getDate());
		String hour = String.valueOf(Now.getHours());
		String minute = String.valueOf(Now.getMinutes());
		String second = String.valueOf(Now.getSeconds());

		return year + "/" + month + "/" + day + " "
			+ hour + ":" + minute + ":" + second;
		//取得目前的日期与时间
	}

	//将BookList中的书籍编号, 建立为以 , 以及 ' 串连的字串
	public String BookID()
	{
		String BookID = "";		
		int start = 0;
		int end = 0;
		int num = 0;

		end = BookList.indexOf(':'); //在BookList字串中寻找':'字元

		//利用while回圈将BookList中的书籍编号串接成BookID字串		
		while(end != -1)
		{
			BookID = BookID + "'" + 
				 BookList.substring(start, end) + "', ";
			//在书籍编号前後加上 ' 并以 , 分隔
			
			end = BookList.indexOf(':', end + 1);			
			start = BookList.indexOf('&', start);
			start = start + 1;			
		}

		return BookID;
	}		
}