userdao.java

实现基本的购物车功能。 eclipse+sqlserver2005 1.主要强调了购物车的业务逻辑。 2

package com.svse.DAO;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;

import com.svse.DBConnection.DBConnection;
import com.svse.bean.Spbean;


public class UserDAO
{
	  Connection conn=null;
	  DBConnection b=new DBConnection();
	  PreparedStatement pre=null;
	  ResultSet rs=null;
	  public UserDAO()
	  {
		  conn=b.getConnection();
	  }

	  
	  public List  getallsp()
	  {
		  List ar=new ArrayList();
		  String sql="select * from t_sp";
		  try
		  {
			  pre=conn.prepareStatement(sql);
			  rs=pre.executeQuery();
			  while(rs.next())
			  {
				  Spbean sp=new Spbean();
				  sp.setS_id(rs.getInt("s_id"));
				  sp.setS_name(rs.getString("s_name"));
				  sp.setS_price(rs.getDouble("s_price"));
				  ar.add(sp);
			  }
		  }
		  catch(Exception e)
		  {
			  e.printStackTrace();
		  }
		  finally
		  {
			  try
			  {
				  if(rs!=null)
				  {
					  rs.close();
				  }
				  if(pre!=null)
				  {
					  pre.close();
				  }
			  }
			  catch(Exception e)
			  {
				  e.printStackTrace();
			  }
		  }
		  return ar;
		  
	  }
	  
	  //
	  public Spbean  getonlysp(int s_id)
	  {
		  Spbean bc=new Spbean();
		  String sql="select * from t_sp where s_id=?";
		  try
		  {
			  pre=conn.prepareStatement(sql);
			  pre.setInt(1,s_id);
			  rs=pre.executeQuery();
			  while(rs.next())
			  {
				 
				  bc.setS_id(rs.getInt("s_id"));
				  bc.setS_name(rs.getString("s_name"));
				  bc.setS_price(rs.getDouble("s_price"));
				  
			  }
		  }
		  catch(Exception e)
		  {
			  e.printStackTrace();
		  }
		  finally
		  {
			  try
			  {
				  if(rs!=null)
				  {
					  rs.close();
				  }
				  if(pre!=null)
				  {
					  pre.close();
				  }
			  }
			  catch(Exception e)
			  {
				  e.printStackTrace();
			  }
		  }
		  return bc;
		  
	  }
	  
	  
	  
}