在一个文本文件中保存的是一系列网址，本代码就是将该文本本件中的链接所对应网站的源代码获取出来并且保存成txt格式，每个链接都有自己的txt文件-Saved in a text file is a series of URLs, the code is the text of the link to the corresponding parts of the site s source code to get out and save as txt format, each link has its own txt file