用java写的一个网络蜘蛛，他可以从指定的URL开始解析抓取网页上的URL，对于抓取到的URL自动分成站内外URL，并可以设置抓取的深度。-Using java to write a Web Spider, he can from the specified URL to start crawling on the page to resolve URL, the URL for the crawler to automatically divided into stations inside and outside the URL, and can set the crawling depth.