基于JAVA技术的网页内容抓取抓取http://www.tianyabook.com/sanguo/上的三国演义的所有章节内容（要求纯文本），写入sgyy.txt中。-Web page content based on JAVA technology crawl crawl all chapters on the Three Kingdoms of http://www.tianyabook.com/sanguo/ (requires plain text), written sgyy.txt