[IDV #TSR-658482]: IDV - Loading most recent HRV images from EUMETSAT ADDE server 193.17.19.4

Hi HansPeter-

> Institution: EUMETSAT
> Package Version: 1.3b2
> Operating System: os.name:Windows XP; os.arch:x86; os.version:5.1;
> Hardware Information: java.vendor:Sun Microsystems Inc.; 
> java.version:1.4.2_08; java.home:C:\\Program Files\\IDV_1.3B2\\jre; 
> j3d.version:1.3.2 fcs (build12); j3d.vendor:Sun Microsystems, Inc.; 
> j3d.renderer:OpenGL;
> Inquiry: If the most recent  HRV image is incomplete (load to EUMETSAT ADDE 
> server not fiinished)
> any laoding of an image sequnece aborts with the following message
> 
> An error has occurred:
> Loading image data
> java.lang.NullPointerException
> 
> This occurs with version 1.3b2 and is appears to be  independent of the 
> platform (XP and SuSE Linux 9.3).
> There is an obvious problem with the handling of the most recent image either 
> at the source or in IDV.

I would say it's both, but mostly with the IDV. ;-)  The server responds with 
"Could not open an image file" which to me seems odd because I would think
it should always be able to return the latest available image (position 0).
However, for the user experience, the IDV is not handling this gracefully.
First, you found a bug in 1.3B2 which is throwing the NullPointerException.
This was fixed and is in the latest release candidate.  However, even
with the fix, there is still an issue if any one of the requested images
cannot be retrieved.

> What could be the solution that would not abort also in case the most recent 
> image is not yet complete?

Right now, the IDV will abort the load if the first (or only) image requested
is not available.  I recently made a change to account for subsequent images
not being available, but it still aborts if the first is not.  Today, I
made a change to account for any of the images not being available with the
behavior being that it will still load the images it can retrieve.  If
no images can be loaded, a message will pop up indicating this.  This solution
gets around the issue your server presents as well as problems if subsequent
images in the time series are not accessible.  How does this solution sound
to you?

> ******************
> Stack trace:
> java.lang.NullPointerException
> at 
> ucar.unidata.idv.control.DisplayControlImpl.updateLegendLabel(DisplayControlImpl.java:2940)
> at 
> ucar.unidata.idv.control.ImageSequenceControl.loadDataInner(ImageSequenceControl.java:595)
> at 
> ucar.unidata.idv.control.ImageSequenceControl.loadData(ImageSequenceControl.java:369)
> at 
> ucar.unidata.idv.control.ImageSequenceControl.loadData(ImageSequenceControl.java:358)
> at 
> ucar.unidata.idv.control.ImageSequenceControl.access$000(ImageSequenceControl.java:98)
> at 
> ucar.unidata.idv.control.ImageSequenceControl$1.run(ImageSequenceControl.java:218)
> at ucar.unidata.util.Misc$2.run(Misc.java:895)
> 
> 
> 
> 


Ticket Details
===================
Ticket ID: TSR-658482
Department: Support IDV
Priority: Normal
Status: Open