shoppingcartimpl.java

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package com.tarena.dao.ipml;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;

import com.tarena.util.*;

import com.tarena.dao.ShoppingCartDao;
import com.tarena.entity.Item;
import com.tarena.entity.Order;
import com.tarena.entity.Product;

public class ShoppingCartImpl implements ShoppingCartDao{
	
	/*
	 * 生成帐单,返回帐单号
	 * */
	public long generateOrder(Order order) {
		Connection con=null;
		Statement st=null;
		ResultSet rs=null;
		con=JdbcUtil.getConnection();
		try {
			st=con.createStatement();
			/*
			 * 帐单存入数据库,得到帐单号
			 * 帐单号在数据表中为主键,设为auto_increment,自动插入记录
			 * */
		
			Long orderId=null;
			double orderCost=order.getCost();
			Long uid=order.getUser().getOid();
			String sql="insert into orders(cost,uid) values('"+orderCost+"','"+uid+"')";
			st.executeUpdate(sql,Statement.RETURN_GENERATED_KEYS);
			/*
			 * 设置Statement的executeUpdate方法参数,使其能返回刚才插入数据库
			 * 的内容的主键值,即帐单号
			 * */
			rs=st.getGeneratedKeys();
			if(rs.next()){
				orderId=rs.getLong(1);
			}
			/*
			 * 将帐单中的条目存入数据库
			 * */
			List items=order.getItems();
			Iterator it=items.iterator();
			while(it.hasNext()){
				Item item=(Item) it.next();
				Integer pid=item.getProduct().getId();
				int number=item.getNumber();
				double cost=item.getCost();
				String sql1="insert into item(pid,number,cost,orderid) values('"+pid+"','"+number+"','"+cost+"','"+orderId+"')";
				st.executeUpdate(sql1);
			}
			return orderId;
		} catch (SQLException e) {
			e.printStackTrace();
		}finally{
			JdbcUtil.release(rs, st, con);
		}
		return 0;
	}
	/*
	 * 列出商品
	 * */
	public List listProduct() {
		List<Product> list=new ArrayList();
		Connection con=null;
		Statement st=null;
		ResultSet rs=null;
		con=JdbcUtil.getConnection();
		String sql="select * from product_bo";
		try {
			st=con.createStatement();
			rs=st.executeQuery(sql);
			while(rs.next()){
				Product p=new Product();
				p.setId(rs.getInt(1));
				p.setName(rs.getString(2));
				p.setDescription(rs.getString(3));
				p.setPrice(rs.getDouble(4));
				list.add(p);
			}
			return list;
		} catch (SQLException e) {
			e.printStackTrace();
			return null;
		}finally{
			JdbcUtil.release(rs, st, con);
		}
		
	/*
	 * 根据商品号得到商品
	 * */
	}
	public Product getProduct(int productId) {
		Connection con=null;
		Statement st=null;
		ResultSet rs=null;
		
		con=JdbcUtil.getConnection();
		try {
			st=con.createStatement();
			String sql="select * from product_bo where id="+productId;
			rs=st.executeQuery(sql);
			Product p=new Product();
			if(rs.next()){
				p.setId(rs.getInt(1));
				p.setName(rs.getString(2));
				p.setDescription(rs.getString(3));
				p.setPrice(rs.getDouble(4));
				return p;
			}
		} catch (SQLException e) {
			e.printStackTrace();
			return null;
		}finally{
			JdbcUtil.release(rs, st, con);
		}
		return null;
	}
	
}