使用GlassFish，您可以定义替代文档根目录来提供战争以外的文件。从文档：

替代文档根

替代文档根（docroot）
基于
，Web应用程序可以为自己的docroot之外的
服务
的某些资源的请求提供服务，无论这些请求是否匹配网站的URI模式中的一个（或
多）
应用程序的备用docroots。

要为
web应用程序或虚拟服务器指定一个备用docroot，
使用 alternatedocroot_n 属性，
其中 n 是一个正整数，
允许指定多个。
此属性可以是
sun-web中
sun-web-app 元素的子元素.xml 文件或虚拟服务器
属性。有关
这些元素的更多信息，请参阅 sun-web-app in
Oracle GlassFish Server 3.0.1
应用程序部署指南 。

所以你可以像这样配置：

 < property name =alternatedocroot_1value =from = / ext / * dir = / path / to / ext/> 
 

请参阅文档以获取完整详情。

I am a bit of a GlassFish beginner, so please forgive my ingnorance on the subject.

Basically we are serving a game website, and to make the client downloadable by our web app we copy it into a directory within domain1. The problem with this is that when redeploying the web app the client downloadable is lost and we have to copy it across again.

I'd like to be able to store the client downloadable in some external location and have GlassFish provide access to it.

I could just hardcode the link into the web app, but then we would lose portability so that's the reason for having GlassFish handle it.

I could also put the client downloadable into our database but that seems like poor use of a database and could also result in poor database performance.

The third option I have found is to add a custom resource mapping from some name to the file location, and then provide a method in one of my beans to retrieve the file location. This seems like a lot of work just to have an external resource, I feel like there must be an easier way.

So what should I do?

With GlassFish you can define an alternate document root to serve files from outside the war. From the documentation:

Alternate Document Roots

An alternate document root (docroot) allows a web application to serve requests for certain resources from outside its own docroot, based on whether those requests match one (or more) of the URI patterns of the web application's alternate docroots.

To specify an alternate docroot for a web application or a virtual server, use the alternatedocroot_n property, where n is a positive integer that allows specification of more than one. This property can be a subelement of a sun-web-app element in the sun-web.xml file or a virtual server property. For more information about these elements, see sun-web-app in Oracle GlassFish Server 3.0.1 Application Deployment Guide.

So you could configure something like this:

<property name="alternatedocroot_1" value="from=/ext/* dir=/path/to/ext"/>

Refer to the documentation for full details.