[netCDFJava #SXF-400193]: NetcdfFileWriter's global Attributes

Hi Jin,

first, make sure you have the latest Netcdf-JAVA library and your directory 
"data" is already created.
Then, I think you are trying to set the root group for the file and you don't 
need to do that. 
You just need: 
writer.addGroupAttribute(null, new Attribute("lat", 100));
so, when you want to get the root group of a file you can either look for a 
null group:
Group root1 = file.findGroup(null);
or an empty String:     
Group root1 = file.findGroup("");
And for getting the global attributes you can also use: 
file.getGlobalAttributes();
If this is the case your code could be:

        NetcdfFileWriter writer = NetcdfFileWriter.createNew(Version.netcdf4, 
"data/foo.nc");
         writer.addGroupAttribute(null, new Attribute("lat", 100));
         writer.create();
         writer.flush();
         writer.close();
         
         NetcdfFile file = NetcdfFile.open("data/foo.nc");
         List<Attribute> attr = file.getGlobalAttributes();

However, if you want to add a group to the root group, I'd suggest not calling 
it "root" (it's pretty confusing) and then your code could be something like 
this:

        NetcdfFileWriter writer = NetcdfFileWriter.createNew(Version.netcdf4, 
"data/foo.nc");
        Group root = writer.addGroup(null, ""); //Gets the root group
        Group newGroup = writer.addGroup(root, "new_group");//Adds a new group 
to the root group
        writer.addGroupAttribute(newGroup, new Attribute("lat", 100));
        writer.create();
        writer.flush();
        writer.close();
         
        NetcdfFile file = NetcdfFile.open("data/foo.nc");
        newGroup = file.findGroup("new_group");
        List<Attribute> attr = newGroup.getAttributes();


Cheers!
Marcos Hermida.



Ticket Details
===================
Ticket ID: SXF-400193
Department: Support netCDF Java
Priority: Normal
Status: Open