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| Author | Forum: PowerWEB LiveControls for ASP.NET Topic: Strange Recurring Null Reference Exception |
| edltech From: hoboken, NJ USA Posts: 3 Member Since: 04/06/06 |
posted October 12, 2006 10:55 PM We are on the latest version in our production environment. We have seen a fair amount of traffic with the following error: ---- System.NullReferenceException: Object reference not set to an instance of an object. at Dart.PowerWEB.LiveControls.ResourceHttpHandler.ProcessRequest(HttpContext hc) at System.Web.CallHandlerExecutionStep.System.Web.HttpApplication+IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) ---- We cannot explain it or catch the error because it is happening in your library. Can you tell us if you've seen this before. The detailed error report below tells us what we can gather from our logs. We cannot recreate it; our site gets a fair amount of traffic from a variety of human traffic, search engines, spiders, etc. We really appreciate your help to help us resolve this. Also, if you could trap the error and maybe throw a custom exception with more info, we could probably deal with this gracefully at our end. Thanks! Ed xyzcorpWEB02 :: ERROR :: Error Caught in Application_Error event Error in: /Dart.PowerWEB.LiveControls.GetResource.aspx Key: ALL_HTTP Value HTTP_CONNECTION:Close HTTP_PRAGMA:no-cache HTTP_ACCEPT:*/* HTTP_HOST:www.xyzcorp.com HTTP_USER_AGENT:Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.5) Gecko/20041107 Firefox/1.0 Key: ALL_RAW Value Connection: Close Pragma: no-cache Accept: */* Host: www.xyzcorp.com User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.5) Gecko/20041107 Firefox/1.0 Key: APPL_MD_PATH Value /LM/W3SVC/570034579/ROOT Key: APPL_PHYSICAL_PATH Value E:\WebSites\Prod\Public\ Key: AUTH_TYPE Value Key: AUTH_USER Value Key: AUTH_PASSWORD Value Key: LOGON_USER Value Key: REMOTE_USER Value Key: CERT_COOKIE Value Key: CERT_FLAGS Value Key: CERT_ISSUER Value Key: CERT_KEYSIZE Value Key: CERT_SECRETKEYSIZE Value Key: CERT_SERIALNUMBER Value Key: CERT_SERVER_ISSUER Value Key: CERT_SERVER_SUBJECT Value Key: CERT_SUBJECT Value Key: CONTENT_LENGTH Value 0 Key: CONTENT_TYPE Value Key: GATEWAY_INTERFACE Value CGI/1.1 Key: HTTPS Value off Key: HTTPS_KEYSIZE Value Key: HTTPS_SECRETKEYSIZE Value Key: HTTPS_SERVER_ISSUER Value Key: HTTPS_SERVER_SUBJECT Value Key: INSTANCE_ID Value 570034579 Key: INSTANCE_META_PATH Value /LM/W3SVC/570034579 Key: LOCAL_ADDR Value 555.212.555.212 Key: PATH_INFO Value /Dart.PowerWEB.LiveControls.GetResource.aspx Key: PATH_TRANSLATED Value E:\WebSites\Prod\Public\Dart.PowerWEB.LiveControls.GetResource.aspx Key: QUERY_STRING Value Key: REMOTE_ADDR Value 66.207.120.227 Key: REMOTE_HOST Value 66.207.120.227 Key: REMOTE_PORT Value 33962 Key: REQUEST_METHOD Value GET Key: SCRIPT_NAME Value /Dart.PowerWEB.LiveControls.GetResource.aspx Key: SERVER_NAME Value www.xyzcorp.com Key: SERVER_PORT Value 80 Key: SERVER_PORT_SECURE Value 0 Key: SERVER_PROTOCOL Value HTTP/1.0 Key: SERVER_SOFTWARE Value Microsoft-IIS/6.0 Key: URL Value /Dart.PowerWEB.LiveControls.GetResource.aspx Key: HTTP_CONNECTION Value Close Key: HTTP_PRAGMA Value no-cache Key: HTTP_ACCEPT Value */* Key: HTTP_HOST Value www.xyzcorp.com Key: HTTP_USER_AGENT Value Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.5) Gecko/20041107 Firefox/1.0 Logger: xyzcorp.Apps.Web.Public.Global Thread: 1044 Date: 2006-10-12 09:16:06,768 NDC: (null) System.NullReferenceException: Object reference not set to an instance of an object. at Dart.PowerWEB.LiveControls.ResourceHttpHandler.ProcessRequest(HttpContext hc) at System.Web.CallHandlerExecutionStep.System.Web.HttpApplication+IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) |
Jeff Cranford From: Rome, NY USA Posts: 586 Member Since: 05/30/01 |
posted October 13, 2006 4:04 PM The problem is occurring in our resource HttpHandler. This handler acts as the endpoint for any external resource used by LiveControls (which are embedded in our dll). This could include JavaScript files, images, or other web resources. The resource is specified in a query string following "GetResource.aspx". It appears from your log below that querystring is null (where normally it would look like "GetResource.aspx?Res=[resource name]". I don't know of any case where our product would make a request like this....we would always include the "Res" variable. It is possible that something/someone else (perhaps a person scanning the source of the HTML and loading the url just to see what it does?) is making this request. You may be able to tell something from your logfiles by examining requests for GetResource.aspx. Also, if this continues to be a problem for you, you can use the resource seperation technique to eliminate the HttpHandler from the process. This technique is described in the readme file installed with the product. |
| edltech From: hoboken, NJ USA Posts: 3 Member Since: 04/06/06 |
posted April 13, 2007 1:35 PM I am revisting this because it looks like v1.6 still throws annoying Null Reference exceptions when it doesn't need to. To your point: I don't know of any case where our product would make a request like this....we would always include the "Res" variable ---- Our web application is high-performance, high-traffic. We are CONSTANTLY being pounded by spiders and hackers. This is why /GetResource is being called without whatever expected values you might need to process without throwing an exception. PLEASE do not throw a null reference exception if this isn't passed in. AT LEAST throw a specific exception (like ArgumentException) so we can catch for that, or eat it. I'd like to see this fixed in the next version. It is making our application diagnostics very difficult. |
K M Drake From: Utica, NY USA Posts: 3406 Member Since: 07/14/00 |
posted April 16, 2007 9:43 AM Hi, I've reported this request to development as issue #4300. For info on the status of this issue, please contact Jamie Powell (jamie.powell@dart.com). Thanks, -ken |
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