代理服务器打开一个端口接收浏览器发来的访问某个站点的请求，从请求的字符串中解析出用户想访问哪个网页，让后通过URL对象建立输入流读取相应的网页内容，最后按照web服务器的工作方式将网页内容发送给用户浏览器 -Proxy server to open a port to receive the browser sent a request to visit a site, from the request to resolve a string which the user would like