Question

I know the request object has a function to get the server name. (i.e. HttpServletRequest.getServerName() )

What if I need the same functionality inside the initialization of a servlet? How do I do this?

Answer 1

This information is request based and not strictly application based. It can namely change per request. All you have at hands during servlet initialization is the ServletContext instance which in turn offers methods like getInitParameter(). You could make use of it to access application wide settings.

So your best bet is to manually set the server name as a context parameter in web.xml

<context-param>
    <param-name>serverName</param-name>
    <param-value>foo</param-value>
<context-param>

so that you can obtain it as follows in servlet’s init() method:

String serverName = getServletContext().getInitParameter("serverName");

Another (not recommended) alternative is to set it as display name in web.xml

<display-name>foo</display-name>

so that you can obtain it as follows:

String serverName = getServletContext().getServletContextName();