bookdao.java

项目名称eShop

/*
 * 创建日期：2006-7-22 17:07:00
 *
 * 代码作者：万星 
 * 
 * 项目名称：eShop
 * 
 * Copyright 2006 北京交通大学信息管理与信息系统系. All right reserved.
 */
package eshop.dataaccess;

import java.sql.*;
import java.util.*;

import eshop.common.*;

/**
 * <h5>功能说明:</h5>
 *
 * <h5>对应需求:</h5>
 * 
 *
 * @version 1.0
 * @author Administrator
 */
public class BookDAO
{
    public BookPO getBookInfoFromDB(int intBookID)throws Exception
    {
        BookPO book=new BookPO();        
        Connection conn=DBConnection.getConnection();        
        Statement stmt=conn.createStatement();
        ResultSet rs=null;
        try
        {   
                       
            String strSQL="select * from T_BOOK,T_CATEGORY where " +
            		" T_CATEGORY.F_CATEGORYID=T_BOOK.F_CATEGORYID and" +
            		" F_BOOKID="+String.valueOf(intBookID);
                        
            rs=stmt.executeQuery(strSQL);            
            
            if(rs.next())
            {
                String strBookName=rs.getString("F_BOOKNAME");
                String strAuthor=rs.getString("F_AUTHOR");
                String strDesc=rs.getString("F_DESC");
                String strPubDate=rs.getString("F_PUBDATE");
                float flPrice=rs.getFloat("F_PRICE");
                float flDisCount=rs.getFloat("F_DISCOUNT");
                String  strCategory=rs.getString("F_CATEGORY");
                String  strPress=rs.getString("F_PRESS");
                String  strPicture=rs.getString("F_PICTURE");
                
                if(strAuthor==null) strAuthor="";
                if(strDesc==null) strDesc="";
                if(strPubDate==null) strPubDate="";
                if(strPress==null) strPress="";
                
                book.setBookName(strBookName);
                book.setBookAuthor(strAuthor);
                book.setBookDesc(strDesc);
                book.setBookPubDate(strPubDate);
                book.setBookPrice(flPrice);
                book.setBookDisCount(flDisCount);
                book.setBookCategory(strCategory);
                book.setBookPress(strPress);
                book.setBookPicture(strPicture);
            }
            else
            {
               book=null;
            }
           
            		
        }
        catch(SQLException e)
        {
            e.printStackTrace();
            throw e;
            
        }
        finally
        {
            conn.close();             
        }
       
        return book;  
    }
    
    public Iterator getBookInfoFromDB()throws Exception
    {
        Collection clnBooks=new ArrayList(); 
        Iterator itrBook=null;               
        Connection conn=DBConnection.getConnection();        
        Statement stmt=conn.createStatement();
        ResultSet rs=null;
        try
        {   
            
           
            String strSQL="select top 4 * from T_BOOK,T_CATEGORY where " +
            		" T_CATEGORY.F_CATEGORYID=T_BOOK.F_CATEGORYID order by F_BOOKID desc";
                        
            rs=stmt.executeQuery(strSQL);            
            
             while(rs.next())
                {                    

                       int    intBookID=rs.getInt("F_BOOKID");
                       String strBookName=rs.getString("F_BOOKNAME");
                       String strAuthor=rs.getString("F_AUTHOR");
                       String strDesc=rs.getString("F_DESC");
                       String strPubDate=rs.getString("F_PUBDATE");
                       float flPrice=rs.getFloat("F_PRICE");
                       float flDisCount=rs.getFloat("F_DISCOUNT");
                       String  strCategory=rs.getString("F_CATEGORY");
                       String  strPress=rs.getString("F_PRESS");
                       String  strPicture=rs.getString("F_PICTURE");
                    
                       if(strAuthor==null) strAuthor="";
                       if(strDesc==null) strDesc="";
                       if(strPubDate==null) strPubDate="";
                       if(strPress==null) strPress="";
                       
                       BookPO book=new BookPO(); 
                       
                       book.setBookID(intBookID);
                       book.setBookName(strBookName);
                       book.setBookAuthor(strAuthor);
                       book.setBookDesc(strDesc);
                       book.setBookPubDate(strPubDate);
                       book.setBookPrice(flPrice);
                       book.setBookDisCount(flDisCount);
                       book.setBookCategory(strCategory);
                       book.setBookPress(strPress);
                       book.setBookPicture(strPicture);
                    
                       clnBooks.add(book);                        
                }
               itrBook=clnBooks.iterator();
          
                                  		
        }
        catch(SQLException e)
        {
            e.printStackTrace();
            throw e;
            
        }
        finally
        {
            conn.close();             
        }
       
        return itrBook;  
    }
    
    public Iterator getBookInfoFromDB(int intBookNum,String returnMethod)throws Exception
    {
        Collection clnBooks=new ArrayList();
        Iterator itrBook;          
        Connection conn=DBConnection.getConnection();        
        Statement stmt=conn.createStatement();
        ResultSet rs=null;
        try
        {   
            String strOrderBy=null;
            if(returnMethod.equals("Method1"))
               {
                  strOrderBy="ORDER BY F_PRICE*(1-F_DISCOUNT) DESC";   
               }
            else if
            (returnMethod.equals("Method2"))
            {
               strOrderBy="ORDER BY F_DISCOUNT DESC";   
            }
                   
            String strSQL="select top "+String.valueOf(intBookNum)+" * from T_BOOK " +strOrderBy;
             
            rs=stmt.executeQuery(strSQL);            
            
            int intNum=0;        
            
                while(rs.next())
                {  
                    int intBookID=rs.getInt("F_BOOKID");  
                    String strBookName=rs.getString("F_BOOKNAME");                                       
                    float flPrice=rs.getFloat("F_PRICE");
                    float flDisCount=rs.getFloat("F_DISCOUNT");                                          
                    BookPO book=new BookPO();   
                    
                    book.setBookID(intBookID);
                    book.setBookName(strBookName);                 
                    book.setBookPrice(flPrice);
                    book.setBookDisCount(flDisCount);
                    intNum++;
                    
                    if(intNum>intBookNum)
                    {
                        break;
                    }
                    
                    clnBooks.add(book);
                      
                                     
                }            
               
            
            itrBook=clnBooks.iterator();           
           
            		
        }
        catch(SQLException e)
        {
            e.printStackTrace();
            throw e;
            
        }
        finally
        {
            conn.close();             
        }
       
        return itrBook;  
    }
}