Check Record or FileName in a SPDocument Library

In this post I discussed how we can check whether a particular record / filename exist in a SPDocumentLibrary (SharePoint's document library) or not.

In the following method, first I discussed the 4 approaches suggested in following blog/forum, then the 5th apporach (in which I used SPQuery).

According to me the 5th and last approach is good-one because it would't raise an Exception.

    /// <summary>
    /// Check FileName/Records in SPDocumentLibrary
    /// </summary>
    void docLibFileExits()
    {
        SPWeb currentSite = SPContext.Current.Web;
        SPDocumentLibrary docLib 
            = (SPDocumentLibrary)currentSite.GetList(currentSite.Url + "/Documents");

        //APPROACH 1
        if (docLib.RootFolder.Files[fileName] != null)
        {
            // do something 
            //This throws an Argument Exception
        }

        //APPROACH 2
        if (docLib.RootFolder.Files[fileName].Exists == true)
        {
            // do something 
            //Again this throws a Argument Exception
        }

        //APPROACH 3
        if (currentSite.GetFile(fileName).Exists == true)
        {
            // do something
            //work
        }

        //APPROACH 4
        bool fileExist = true;

        try { docLib.RootFolder.Files[fileName]; }
        catch (ArgumentException) { fileExist = false; }

        if (fileExists)
        {
            //...
        }

        

        //APPROACH 5
        SPSite oWebsite = SPContext.Current.Web;
        SPList docLib = oWebsite.Lists["docLib"] as SPDocumentLibrary;
        SPListItemCollection itemcolCVs = null;
        SPQuery oQueryFileCheck = new SPQuery();

        string FILENAME = ""; //FileName that you want to search.

        //You can use EQUALS or CONTAINS operation as per your requirement.
        //
        /*
        StringBuilder strBFileCheckQuery = new StringBuilder(
            "<Where>" +
                "<Eq>" +
                    "<FieldRef Name='FileLeafRef' />" +
                    "<Value Type='Text'>FILENAME</Value>" +
                "</Eq>" +
            "</Where>");
        */

        StringBuilder strBFileCheckQuery = new StringBuilder(
            "<Where>" +
                "<Contains>" +
                    "<FieldRef Name='FileLeafRef' />" +
                    "<Value Type='Text'>FILENAME</Value>" +
                "</Contains>" +
            "</Where>");

        oQueryFileCheck.Query = strBFileCheckQuery.ToString();
        if (docLib.GetItems(oQueryFileCheck).Count > 0)
        {
            //To do
        }
        
    }

P.S. Here CAML Query Builder helped me a lot to identify and build above SPQuery.