Re: NetCDF java libraries: versions 1 and 2

Scott Neu wrote:
> Hello,
>
> I know I'm somewhat behind the times, but a while ago I downloaded the
> NetCDF java library version 1 and integrated that into my code. 
> Everything has been great up until last July, when I started to receive
> reports that my code was no longer able to parse certain NetCDF files.
>
> The obvious solution is to upgrade to version 2, but the class library
> has changed too much for me to do this quickly (and I just don't have
> the time right now).
>
> My question is:  is there a quick patch I can write to parse these newer
> NetCDF files using the version 1 library? 

no, im afraid version 1 is no longer maintained.

Did a substantial change
> occur in the definition of NetCDF files?

one  possibility is that you are seeing truncated files. double check with the 
C library ncdump program, and dump the values of the last variable in the file. 
if that fails, you have a truncated file.

otherwise, maybe you are seeing the "truncated netcdf problem" where the writer 
doesnt write all the bytes to the file. this has always been there and i guess you are 
just seeing these now (??).

there has been a change to allow files > 2 GB, but those files are not in wide 
circulation. dump out the first 4 bytes of your file, old version has CDF1 and new 
has CDF2 (where the 4th byte is numeric, not character)

> I get end-of-file errors as the offsets to the variable data are larger
> than the file lengths themselves.
>
> thanks for any helpful advice,
> Scott
>
> java.io.EOFException
>         at
> javax.imageio.stream.ImageInputStreamImpl.readInt(ImageInputStreamImpl.java:235)
>         at
> ucar.netcdf.NetcdfStream$V1IntegerIo.readArray(NetcdfStream.java:1090)
>         at ucar.netcdf.NetcdfStream$V1Io.toArray(NetcdfStream.java:757)
>         at ucar.netcdf.NetcdfStream$V1Io.toArray(NetcdfStream.java:721)
>         at ucar.netcdf.Variable.toArray(Variable.java:296)
>         at ucar.nc2.Variable.read(Variable.java:229)
>         at ucar.nc2.NetcdfStream.cacheData(NetcdfStream.java:102)