NullPointerException during aggregation

• To: netcdf-java <netcdf-java@xxxxxxxxxxxxxxxx>
• Subject: NullPointerException during aggregation
• From: "Jon Blower" <jdb@xxxxxxxxxxxxxxxxxxxx>
• Date: Fri, 3 Nov 2006 14:26:13 +0000

Hi all,

I'm having problems working with NcML aggregations and the 2.2.16
version of the Java NetCDF libraries.  I would like to aggregate
files:

NATL_1_28082006.nc
NATL_1_29082006.nc
NATL_1_30082006.nc
...

along the time dimension.  I tried an NcML file like this:

<netcdf xmlns="http://www.unidata.ucar.edu/namespaces/netcdf/ncml-2.2";>
  <aggregation dimName="time" type="joinNew">
    <variableAgg name="temperature"/>
    <variableAgg name="salinity"/>
    <scan location="/path/to/files/" suffix=".nc"
dateFormatMark="NATL_1_#ddMMyyyy" />
  </aggregation>
</netcdf>

This gave me a NullPointerException:

java.lang.NullPointerException
        java.util.Calendar.setTime(Calendar.java:1032)
        java.text.SimpleDateFormat.format(SimpleDateFormat.java:785)
        java.text.SimpleDateFormat.format(SimpleDateFormat.java:778)
        java.text.DateFormat.format(DateFormat.java:314)
        ucar.nc2.units.DateFormatter.toDateTimeStringISO(DateFormatter.java:184)
        ucar.nc2.ncml.Aggregation.crawlDirectory(Aggregation.java:817)

I think I know why this is.  There are other files in the same
directory of the form "NATL_120_28082006.nc" and I think the
aggregator is trying to match these.  Can I arrange it so that only
files that match the pattern "NATL_1_#ddMMyyyy.nc" are aggregated, and
all others are simply ignored?

I am reluctant to change the directory structure of my data because
other applications may depend on it.

Thanks in advance,
Jon

--
--------------------------------------------------------------
Dr Jon Blower              Tel: +44 118 378 5213 (direct line)
Technical Director         Tel: +44 118 378 8741 (ESSC)
Reading e-Science Centre   Fax: +44 118 378 6413
ESSC                       Email: jdb@xxxxxxxxxxxxxxxxxxxx
University of Reading
3 Earley Gate
Reading RG6 6AL, UK
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