JDBC访问数据库最佳代码

package reusing;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
//注册驱动程序常量
class Constant{
	public static final String URL="jdbc:oracle:thin:@127.0.0.1:1521:sid";
	public static final String USERNAME="username";
	public static final String PASSWORD="password";
}
@SuppressWarnings("serial")
class DAOException extends Exception{
	public DAOException(){
		super();
	}
	public DAOException(String msd){
		super(msd);
	}
}

public class jdbcConnect {
		public void printProducts() throws DAOException{
			Connection c=null;
			Statement s=null;
			ResultSet r=null;
			try{
				//建立连接
				c=DriverManager.getConnection(Constant.URL,Constant.USERNAME,Constant.PASSWORD);
				s=c.createStatement();
				r=s.executeQuery("select id,name,price from t_product");
				System.out.println("ID\tNAME\tPRICE");
				while(r.next()){
					int x=r.getInt("id");
					String y=r.getString("name");
					float z=r.getFloat("price");
					System.out.println(x+"\t"+y+"\t"+z);
				}
			}catch(SQLException e){
				throw new DAOException("数据库异常");
			}finally{
				try{
					//关闭连接
					r.close();
					s.close();
					c.close();
				}catch(SQLException e){
					e.printStackTrace();
				}
			}
		}
}