[thredds] XML question for WCS THREDDS catalogs

• To: Ethan Davis <edavis@xxxxxxxxxxxxxxxx>, John Caron <caron@xxxxxxxxxxxxxxxx>, thredds@xxxxxxxxxxxxxxxx
• Subject: [thredds] XML question for WCS THREDDS catalogs
• From: Nathan Potter <ndp@xxxxxxxxxxx>
• Date: Wed, 24 Oct 2007 09:50:53 -0700

Ethan and John,

The catalog entry is:


    <dataset name="CCEXTTAU-INTEX.Organic+Black.Carbon.Aerosol"

        <property name="returnType" value="netCDF" />
        <property name="cacheTime" value="600" />
        <serviceName>OPeNDAP-Hyrax</serviceName>
   </dataset>



The stack trace that I get is:

java.lang.NullPointerException

        at opendap.coreServlet.DispatchServlet.doGet(DispatchServlet.java:437)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

Any ideas?


N








Begin forwarded message:

From: Daniel Holloway <d.holloway@xxxxxxxxxxx>
Date: October 23, 2007 11:01:37 AM PDT
To: Nathan Potter <ndp@xxxxxxxxxxx>
Subject: Re: XML question for WCS THREDDS catalogs


On Oct 23, 2007, at 1:53 PM, Nathan Potter wrote:

On Oct 23, 2007, at 10:01 AM, Daniel Holloway wrote:

On Oct 23, 2007, at 12:21 PM, Nathan Potter wrote:

Dan,

Several things strike me as potential problems:

1) The Exception is being thrown deep in the THREDDS code. Disturbingly, it appears to be in a servlert implmentation that I am not running in Hyrax. Are you running a TDS too?

   Hi Nathan,

Thanks for the quick reply. No, I'm not running a TDS on this platform as well.

2) A plus sign in a URL (outside of the constraint expression) mught get filtered by the new security features in the PLFS, and this would cause trouble!

It's not a big problem for me, I was more interested in knowing where the problem existed and why. If these characters aren't allowable in XML, or THREDDS, then I need to document that in the configuration guide for the handler. It seems to me that these are valid characters, or at least should be able to be replaced with '&plus' without it causing these problems.

    Anyway, welcome back and thanks for the reply.

       Dan

p.s. Should we enter a ticket on this to keep track of the problem?

I think so. I am still pretty non functional from jet lag.... I'll be on my game tomorrow and I'll try to tack it down. Will you send me the THREDDS catalog entry that caused the error?

   Nathan,

Here's the dataset element that is causing the problem. The best bet is to replace the element in your example catalog.xml with this one. The problem seems to be the '+' sign in the ID attribute. I've experimented and found that it only fails when the '+' sign is in the ID attribute, no idea why.

--------

<dataset name="CCEXTTAU-INTEX.Organic +Black.Carbon.Aerosol" urlPath="wcs/DataFed/NetCDF/CCEXTTAU- INTEX.Organic+Black.Carbon.Aerosol" ID="wcs/DataFed/NetCDF/CCEXTTAU-INTEX.Organic +Black.Carbon.Aerosol" > <property name="wcs-request" value="http:// webapps.datafed.net/ogc_NASA.wsfl? SERVICE=WCS&amp;REQUEST=GetCoverage&amp;VERSION=1.0.0&amp;CRS=EPSG: 4326&amp;COVERAGE=GOCART_G_OL.CCEXTTAU&amp;TIME=2007-06-24T23:00:00&am p;BBOX=-180,-90,\ 180,90,0,0&amp;WIDTH=-1&amp;HEIGHT=-1&amp;DEPTH=-1&amp;FORMAT=NetCDF" />

                <property name="returnType" value="netCDF" />
                <property name="cacheTime" value="600" />
                <serviceName>OPeNDAP-Hyrax</serviceName>
           </dataset>

-------

   Dan

N

N






On Oct 23, 2007, at 8:52 AM, Daniel Holloway wrote:

Nathan,

I've been playing with the configuration of a Hyrax server using the latest OLFS/BES code. There is/was a dataset that has a '+' sign in the name. I get an error from the OLFS when using this string in the ID attribute of the dataset element. As follows:

------

<dataset name="CCEXTTAU-INTEX.Organic +Black.Carbon.Aerosol" urlPath="wcs/DataFed/NetCDF/CCEXTTAU- INTEX.Organic+Black.Carbon.Aerosol" ID="wcs/DataFed/NetCDF/CCEXTTAU- INTEX.Organic+Black.Carbon.Aerosol" > <property name="wcs-request" value="http:// webapps.datafed.net/ogc_NASA.wsfl? SERVICE=WCS&amp;REQUEST=GetCoverage&amp;VERSION=1.0.0&amp;CRS=EPSG : 4326&amp;COVERAGE=GOCART_G_OL.CCEXTTAU&amp;TIME=2007-06-24T23:00:0 0&amp;BBOX=-180,-90,\ 180,90,0,0&amp;WIDTH=-1&amp;HEIGHT=-1&amp;DEPTH=-1&amp;FORMAT=NetC DF" />

                <property name="returnType" value="netCDF" />
                <property name="cacheTime" value="600" />
                <serviceName>OPeNDAP-Hyrax</serviceName>
           </dataset>
-------

   The error is:
-------

Error { code = -1; message = "java.lang.NullPointerException: null [CatalogServicesServlet.java - line 226]"; };

-------

I only get an error if the '+' sign is used in the 'ID' attribute, the others don't seem to make any difference. I've tried replacing the '+' with a &plus; but that breaks the server's access to the catalog completely. Not exactly sure why but if I use a &plus; in the XML I get a 'Resource Not Found' response from the server when trying to open the catalog.

  Anyway, figured I'd ask before submitting a Trac ticket.

  Dan

= = =
Nathan Potter                        ndp at opendap.org
OPeNDAP, Inc.                        541.752.1852

= = =
Nathan Potter                        ndp at opendap.org
OPeNDAP, Inc.                        541.752.1852

= = =
Nathan Potter                        ndp at opendap.org
OPeNDAP, Inc.                        541.752.1852

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  • Re: [thredds] XML question for WCS THREDDS catalogs
    • From: Ethan Davis