old_contents: # -*- coding:utf-8 -*-
  import os,time,asyncio,json
  import logging
  logging.basicConfig(level=logging.ERROR)
  try:
  	from aiohttp import web
  except ImportError:
  	logging.error("Can't import module aiohttp")
  from tools.log import Log
  from tools.httptools import Middleware,Route
  from tools.template  import Template
  from tools.config import Config
  from tools.database import create_pool
  logging.basicConfig(level=logging.INFO)
  class Application(web.Application):
  	def __init__(self):
  		self._loop=asyncio.get_event_loop()
  		super(Application,self).__init__(loop=self._loop,middlewares=Middleware.allmiddlewares())
  	def run(self,addr='127.0.0.1',port='8000'):
  		self._loop.run_until_complete(self.get_server(addr,port))
  		self._loop.run_forever()
  	@asyncio.coroutine
  	def get_server(self,addr,port):	
  		Template.init(self)
  		Route.register_route(self)
  		pool=yield from create_pool(self._loop)
  		srv=yield from self._loop.create_server(self.make_handler(),addr,port)
  		logging.info("server start at http://%s:%s"%(addr,port))
  		Log.info("server start at http://%s:%s"%(addr,port))
  		print("server start at http://%s:%s"%(addr,port))
  		return srv
  
new_contents: # -*- coding:utf-8 -*-
  import os,time,asyncio,json
  import logging
  logging.basicConfig(level=logging.ERROR)
  try:
  	from aiohttp import web
  except ImportError:
  	logging.error("Can't import module aiohttp")
  from tools.log import Log
  from tools.httptools import Middleware,Route
  from tools.template  import Template
  from tools.config import Config
  from tools.database import create_pool,DB
  logging.basicConfig(level=logging.INFO)
  class Application(web.Application):
  	def __init__(self):
  		self._loop=asyncio.get_event_loop()
  		super(Application,self).__init__(loop=self._loop,middlewares=Middleware.allmiddlewares())
  	def run(self,addr='127.0.0.1',port='8000'):
  		self._loop.run_until_complete(self.get_server(addr,port))
  		self._loop.run_forever()
  	@asyncio.coroutine
  	def get_server(self,addr,port):	
  		Template.init(self)
  		Route.register_route(self)
  		yield from DB.createpool(self._loop)
  		#pool=yield from create_pool(self._loop)
  		srv=yield from self._loop.create_server(self.make_handler(),addr,port)
  		logging.info("server start at http://%s:%s"%(addr,port))
  		Log.info("server start at http://%s:%s"%(addr,port))
  		print("server start at http://%s:%s"%(addr,port))
  		return srv
  
subject: Change the way of creating database's connection pool