Is it possible to determine if a given URL represents an SPListItem?

Question

I am wondering if there is some sort of way to check a URL to see if it represents a list item before calling SPWeb.GetListItem that I haven't found.

I have code that needs to retrieve a list item for a given URL, and do something if it is a list item, but that URL may well not be a list item. SPWeb.GetListItem throws exceptions that even when caught mess things up at the SharePoint level in certain circumstances (log shows <nativehr>0x80070002</nativehr><nativestack></nativestack>, user gets "Cannot complete this action"). I tried using SPWeb.GetFile as well, that causes even more exceptions in the log and the same error message.

            using (SPSite spSite = new SPSite(url))
            {
                using (SPWeb spWeb = spSite.OpenWeb())
                {
                    try
                    {
                         m_spListItem = spWeb.GetListItem(url);
                         if (m_spListItem != null)
                         {
                             return true;
                         }                            
                    }
                    catch (Exception e)
                    {
                        // Expected when not a list item
                    }
                    return false;
               }
        }

Edit: I've been thinking of CAML, but the following comes back with no results (for a known good URL in SP CAML Query Helper). Perhaps the Type needs to be different? But URL doesn't work either.

<Where>
  <Eq>
    <FieldRef Name="EncodedAbsUrl" />
    <Value Type="Text">http://site/List/docName.docx</Value>
  </Eq>
</Where>

Edit - Sept 26: Looks like you can query on EncodedAbsUrl - by giving it an UNENCODED URL. I was testing in Shared Documents and using "Shared%20Documents" in the path, which found nothing, but "Shared Documents" works.

Answer 1

In the examples I have seen of this it is usually done in a very dirty way similar to how you are attempting to do it there.

However it is designed to throw System.IO.FileNotFoundException in which case look here.

Answer 2

While I can't quite determine why your exception handling is not working for SPWeb.GetListItem there are two things you should note:

• For at least SPWeb.GetListItem (this may apply to GetFile as well - the MSDN page I looked at doesn't specify for that method), make sure that your URL is server relative or absolute. Other types including web relative likely will not work here.
• When you use SPWeb.GetFile is that you can't simply check for null. There is an Exists property of SPFile that you need to check for.