说明：  从一个网页中提取主要内容，如从新闻网页中提取新闻内容，是web抽取的一项工作。本程序对于有主内容的网页，提取它的主要内容。 程序用java编写，需要jdk5.0。需要用户将网页另存在上面程序所在的test目录下
(From a web page to extract the main content, such as extracted from the news page news content is taken from a work web. This procedure has the main content for web pages, extract its main content. Procedures used to prepare java need jdk5.0. The need for users to another page where the existence of the above procedures test directory)