如何使用javascript更新web服务器中的文件

I need to know, is it possible to find a file in web server is updated using javascript. In my java application i am updating one file using java if any error occurs say, like logger.. By using javascript i need to read that file immediately if any updates occured and show it in a web page... First i need to know is it possible to do that ??? If so, Can u come up with a idea to do that??? If possible with a clear code or example.... Thanx in advance..I need to know, is it possible to find a file i