本程序的结构原理如下： 对于每一个用户的请求（Internet 请求，由浏览器发出），本程序将启动两个线程，一个把本地用户的请求数据发送到远程的Internet主机，另一个线程把远程主机的回应数据发送到本地请求用户。 -Structural principle of this procedure are as follows: For each user s request (Internet request, issued by the browser), this procedure will start two threads, a local user s request data is sent to a remote Internet host, another thread the remote host to respond to data requests sent to local users.