Author | Topic: LoadFromUrl returns NIL | |
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Jose Adriano Baltieri | LoadFromUrl returns NIL on Tue, 12 Mar 2013 08:40:30 -0300 Hello ! I have a kind of a server of my own, that is a multi-threaded app written in XPP. I accepts connections via TCP/IP from OUTSIDE and issues a LoadFromURL to INSIDE, that is, to localhost (127.0.0.1). I then gets a url and returns it to OUTSIDE as as string. It happens that sometimes LoadFromURL returns NIL and I don't know WHY , that is, if it is a timeout problem or a TCP/IP exhaustion one. Say that Windows (2003 R2) is running out of some resource or whatever. The question is : when LoadFromURL returns NIL , I need to know why it happened... tHanXs ! | |
Thomas Braun | Re: LoadFromUrl returns NIL on Wed, 13 Mar 2013 08:54:31 +0100 Jose Adriano Baltieri wrote: > > The question is : when LoadFromURL returns NIL , I need to know why it happened... I think you don't have any finer control at all, this is what teh docs say: > The return value NIL indicates a connection failure which can have > several reasons: The URL does not exist, illegal parameters are passed, > the HTTP server is offline or there is no TCP/IP connection at all. If > there is no TCP/IP connection but the computer is configured for a > dial-up connection via modem, the operating system will open the dial-up > dialog to establish a connection. So either you use the low-level socket functions and create your own HTTP client function or you save yourself a lot of time and get xb2net from Boris and use xbHTTPClient class: > Execute(xURI, [cCommand], [xPostContent], [aHTTPHeaders], [xRecvFile]) -> oHTTPResponse | NIL > Send a request to a remote HTTP server and receive response. If > successful, the method returns a reference to an xbHTTPResponse instance > containing the deserialized response returned by the remote HTTP server. > If an error occurs, the method returns NIL. The cause of the error can > be determined by inspecting values saved in the :ErrorCode, :ErrorMessage > and :ErrorSource instance variables. HTH Thomas |