Checking for validity of an include

If  ihave the below code and want to check if the include is valid and not null, can this be done?

for example, if I pass an invalid include name that is not the correct name, can I catch this and not throw an error?

//////////////////////////////

Code
/////////////////////////////

<% String incName = request.getParameter("incName"); %>

<%
  if( incName != null )
  {
      String varincludefile ="includes/" + incName; %>

     <jsp:include page="<%=varincludefile%>" flush="true" />
<%
  }
%>

///////////////////////////////////////////////

I want incName to be a valid include name. How do I check this?
894359Asked:
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Mick BarryJava DeveloperCommented:
jsp:include's are processed at request time so you shopuld be able to do that.
What you want to do is check for the existence of the file, perhaps using getRealPath() to get the file path of the include and check it exists.
0
Mick BarryJava DeveloperCommented:
something like:

<%
  if( incName != null )
  {
      String varincludefile ="includes/" + incName; %>
      File inc = application.getRealPath(varincludefile);
      if (inc.exists())
      {
%>
          <jsp:include page="<%=varincludefile%>" flush="true" />
<%
      }
   }
%>
0
rrzCommented:
>File inc = application.getRealPath(varincludefile);
more like  
File inc = new File(application.getRealPath(varincludefile));
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Mick BarryJava DeveloperCommented:
woops :)
0
kennethxuCommented:
According to servlet/jsp specification, there is nothing going to happen if the including resource not exists.
I had verified this in tomcat. will check against weblogic and websphere and get back.

application.getRealPath will always return null when the webapp is deployed as web application archive file (war), so use with caution.
0

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kennethxuCommented:
My point is there is no need to check anything.
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kennethxuCommented:
result:
Tomcat 4, Weblogic 8, WebSphere 5 work as to spec.

Tomcat 3: exception (different exception in subversions)
WebSphere 4: 404 Not Found error message on page.

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