def updateInfo(self, item, newlinks, oldlinks):
		'''爬虫爬完之后对数据库内容进行更新'''
		cur = self.conn.cursor()
		cur.execute("SELECT wid,did FROM Websites WHERE url=?", (item['url'],))
		wid, did = cur.fetchone()
		# website记录更新
		cur.execute("UPDATE Websites SET title=?,visited=1 WHERE wid=?", (item['title'], wid,))
		# 对应的domain记录中出度也需要更新
		cur.execute("UPDATE Domains SET outdegree=outdegree+? WHERE did=?", (len(item['links']), did,))

		# 对该网页中所有链接涉及的记录进行更新
		# 外部判断未出现过的链接
		for link,domain in newlinks:
			self.insertWebsite(link, domain)

		# 外部判断出现过的链接
		for link,domain in oldlinks:
			# 对对应的domain记录入度增加
			cur.execute("UPDATE Domains SET outdegree=outdegree+1 WHERE domain=?", (domain,))
		# 写入到文件
		self.conn.commit()
def request_message_txt(self):
        """
        This is the body of the request we send across. This is never actually
        used in the code, but exists for debugging purposes -- you can call
        `print attempt.request_message_txt()` on the console and get a readable
        rendering of the request that would be sent across, without actually
        sending anything.
        """
        headers, body = self.create_request()

        header_txt = "\n".join(
            u"{}: {}".format(h, v) for h, v in sorted(headers.items())
        )
        body_txt = json.dumps(body, indent=2, sort_keys=True, ensure_ascii=False).encode('utf-8')

        return header_txt + "\n\n" + body_txt