keepbook.java

一个简单实用的网上书城,可当作原型使用

/*
 * Keepbook.java
 *
 * Created on 2007年7月26日, 上午9:28
 *
 * To change this template, choose Tools | Template Manager
 * and open the template in the editor.
 */

package czm;

import java.sql.*;
import java.sql.Connection;

/**
 *
 * @author Administrator
 */
public class Keepbook {
    public String userID;//用户帐号
    public String bookid;//书本isbn
    public String keepdate;//收藏日期
       
    public String bookname;//
    public String price;//
    
    private static String strDBDriver = "sun.jdbc.odbc.JdbcOdbcDriver";  //JDBC驱动
    private static String strDBUrl = "jdbc:odbc:bookstore";   //数据源 ，
    private Connection conn =null;             //连接
    private ResultSet rs = null;
    
    
    
    /** Creates a new instance of Keepbook */
    public Keepbook() {
        //加载JDBC-ODBC驱动
        try {
                Class.forName(strDBDriver );
                conn = DriverManager.getConnection(strDBUrl);
        }
        //捕获异常
        catch(java.lang.ClassNotFoundException cnfe){
                System.err.println("Keepbook():" + cnfe.getMessage());
        }catch(java.lang.Exception e){
                System.err.println("Keepbook():" + e.getMessage());
        }
    }
    
    
  
       private ResultSet sqlExecuteQuery(String sql){
        try{
        //创建可滚动的结果集。
        Statement stmt = conn.createStatement();
        rs = stmt.executeQuery(sql);
        return rs;
        }catch(Exception ex){
            return null;
        }        
    }
   
    
   private boolean Isexist(String userID,String bookid) {//检查是否有相同的藏书
        try {
            if(userID == null || bookid == null || userID.equals("") || bookid.equals(""))
                return true;
            String sql="select BookISBN from Keepbook where memberID='"+userID+"'";
            ResultSet rs=sqlExecuteQuery(sql);
            while(rs.next()){
                String tempbookid = rs.getString("BookISBN");
                if(tempbookid.equals(bookid))
                    return true;
            }
            return false;
        } catch(Exception exc) {
            return true;
        }
    }
    
   private void sqlExecuteUpdate(String sql)throws Exception{
               Statement stmt = conn.createStatement();             
                stmt.executeUpdate(sql);
                stmt.close();
    }
   
    public boolean Deletebook(String userID,String bookid) {/**删除*/
        try {
            if(userID == null || bookid == null || userID.equals("") || bookid.equals(""))
                return false;            
            String sql="delete from Keepbook where memberID='"+userID+"' and BookISBN='"+bookid+"'";
            sqlExecuteUpdate(sql);
            return true;
        } catch(Exception exc) {
            return false;
        }
    }
    
    public boolean DeleteAllBook(String userID) {/**删除所有*/
        try {
            if(userID == null || userID.equals(""))
                return false;      
            String sql="delete from Keepbook where memberID='"+userID+"'";
            sqlExecuteUpdate(sql);
            return true;
        } catch(Exception exc) {
            return false;
        }
    }
    
    
     public boolean Inserbook(String userID,String bookid) {/**插入 */
        try {           
            //检查是否有相同的用户
            if(Isexist(userID,bookid)) return false;
            System.out.println((new java.util.Date()).toLocaleString());
            String sql = "insert into Keepbook values('"+userID+"','"+bookid+"',#"+(new java.util.Date()).toLocaleString()+"#)";
            sqlExecuteUpdate(sql);
            return true;
        } catch(Exception exc) {
            System.out.println((new java.util.Date()).toLocaleString());
            return false;
        }
    }
    
    public ResultSet Showbook(String userID) {/**显示*/
        try {
            if(userID == null || userID.equals(""))
                return null;
            String sql = "select Keepbook.BookISBN,bookinfo.bookName,Keepbook.keepdate,bookinfo.price  from Keepbook,bookinfo where Keepbook.memberID='"+userID+"' and bookinfo.bookISBN=Keepbook.BookISBN  order by Keepbook.keepdate desc";
            return sqlExecuteQuery(sql);
          } catch(Exception Exc) {
            return null;
        }
    }    
}