Re: [netcdfgroup] How to read grib2 files using Netcdf Java API?

• To: John Caron <caron@xxxxxxxxxxxxxxxx>
• Subject: Re: [netcdfgroup] How to read grib2 files using Netcdf Java API?
• From: Valliappa Lakshmanan <valliappa.lakshmanan@xxxxxxxx>
• Date: Tue, 20 Jan 2009 14:32:01 -0600

John,

I downloaded the latest netcdf-4.0.jar and tried it.  I still get the same
problem.  Here's the stacktrace, in case the line numbers help isolate the
issue:

    [java] 2009-01-20 14:26:46,867 [main] WARN
org.wdssii.ncingest.Grib2Ingest - java.io.IOException: Cant read
/scratch2/lakshman/modelmining/WRFPRS_GrbF21.grib2: not a valid NetCDF file.
     [java]     at ucar.nc2.NetcdfFile.open(NetcdfFile.java:628)
     [java]     at ucar.nc2.NetcdfFile.open(NetcdfFile.java:335)
     [java]     at ucar.nc2.NetcdfFile.open(NetcdfFile.java:305)
     [java]     at ucar.nc2.NetcdfFile.open(NetcdfFile.java:292)
     [java]     at ucar.nc2.NetcdfFile.open(NetcdfFile.java:280)

The code that throws the exception is simply:
     NetcdfDataset.open("/scratch2/..../filename.grib2");

My classpath consists of the following jar files (netcdf dependencies in
bold):

commons-logging.jar
*jdom_1.1.jar*
jnotify-0.91.jar
jstl.jar
junit.jar
*log4j-1.2.14.jar*
*netcdf-4.0.jar*
servlet-api.jar
*slf4j-api-1.1.0.jar
slf4j-log4j12-1.1.0.jar*
spring.jar
standard.jar

thanks
Lak


On Fri, Dec 12, 2008 at 6:06 PM, John Caron <caron@xxxxxxxxxxxxxxxx> wrote:

> Hi Lak:
>
> Im not having any trouble opening from either 4.0 or latest 2.2. Can you
> recheck your classpath? Also 4.0 has got less bugs in it at this point, so
> you might try it.
>
> Valliappa Lakshmanan wrote:
> > John, thanks for looking at this. The file (74MB) is now at:
> >
> >
http://cimms.ou.edu/~lakshman/data/WRFPRS_GrbF21.grib2<http://cimms.ou.edu/%7Elakshman/data/WRFPRS_GrbF21.grib2>
> >
> > Lak
> >
> >
> > On Fri, Dec 12, 2008 at 1:28 PM, John Caron <caron@xxxxxxxxxxxxxxxx
> > <mailto:caron@xxxxxxxxxxxxxxxx>> wrote:
> >
> >     Hi Lak:
> >
> >     NetcdfDataset.open() should have worked.
> >
> >     Can you send us the file, and we'll check why its not working.
> >
> >     Valliappa Lakshmanan wrote:
> >     > I know there must be a very simple way to do this, but I can't seem
> to
> >     > find any example or documentation.
> >     >
> >     > I want to read a Grib2 file using the Java Netcdf API and tried:
> >     >
> >     > File file = new File("/tmp/WRFPRS_GrbF21.grib2");  // a grib2 file
> >     > NetcdfFile ncfile = NetcdfDataset.open(file.getAbsolutePath());
> >     >
> >     > but get an IOException stating: Cant read
> >     /tmp/WRFPRS_GrbF21.grib2: not
> >     > a valid NetCDF file.
> >     >
> >     > I tried using ucar.dt.grid.GridDataSet.open() and got the same
> result.
> >     >
> >     > In case it was a classpath/jar problem, I added toolsUI.jar from
> >     netcdf
> >     > 2.2.22 to my classpath (has grib.jar).
> >     > Same result.  What am I missing?
> >     >
> >     > thanks
> >     > Lak
> >     >
> >     >
> >     >
> >     >
> >
> ------------------------------------------------------------------------
> >     >
> >     > _______________________________________________
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> >
> >
>

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