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[netCDF #ORC-296912]: Issue Opening HDF5 database

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  • Subject: [netCDF #ORC-296912]: Issue Opening HDF5 database
  • Date: Mon, 23 Apr 2018 13:09:09 -0600
> Hello,
> 
> I have an HDF5 database supplied by an external party that I am trying to 
> read in Java using version 4.6.11 of the NetCDF library. When I open the file 
> using NetcdfFile.open (path) using a path returned from a JFileChooser and 
> for which File.exists() returns true, I get a NullPointerException as follows:
> 
> Java.io.IOException : Java.lang.NullPointerException
> NetcdfFile.java : 427, open ()
> NetcdfFile.java : 394, open ()
> NetcdfFile.java : 381, open ()
> NetcdfFile.java : 369, open ()
> 
> And when I do System.out.println (except.getMessage()); with the caught 
> exception, I get "null".
> 
> I am not sure if the database has a field value that the NetCDF library is 
> not expecting. I was able to open the database using a validation tool, so 
> that Windows-specific application does not seem to have a problem opening the 
> HDF5 file.
> 
> Is there any way that I can figure out what is causing this problem as the 
> information from the exception is particularly unenlightening?  I did not 
> know if the source code for NetcdfFile.java was available for review anywhere 
> or whether this might be a bug in the library that is not checking to see if 
> a field is defined before accessing it?  Any help would be most appreciated.
> 
> Thank You,
> -Creig Donnald

Greetings Creig!

The netCDF-Java library is on github, and can be found here:

https://github.com/unidata/thredds

Version 4.6.x is the master branch. Specifically, the code for NetcdfFile is 
here:

https://github.com/Unidata/thredds/blob/master/cdm/src/main/java/ucar/nc2/NetcdfFile.java

However, most likely, the error is occurring at the HDF5 IOSP layer:

https://github.com/Unidata/thredds/tree/master/cdm/src/main/java/ucar/nc2/iosp/hdf5

It's hard to diagnose the exact problem without the file that is causing the 
error - is
there any chance we could get a copy of it to take a look locally?

Thank you!

Sean

Ticket Details
===================
Ticket ID: ORC-296912
Department: Support netCDF Java
Priority: Normal
Status: Open
===================
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