[netcdf-java] OPeNDAP authentication using nj22

[Jon Blower]

Thanks John, and everyone else who replied.

I'm now experimenting with trying to get OPeNDAP authentication
working in version 2.2.22.  I have a very simple main() method that
simply tries to open a NetcdfDataset from an OPeNDAP URL, where the
OPeNDAP server requires authentication:

    public static void main(String[] args) throws Exception
    {
        HttpClientManager.init(new CredentialsProvider(){
            public Credentials getCredentials(AuthScheme scheme,
                       String host, int port, boolean proxy)
                       throws CredentialsNotAvailableException
            {
                System.out.println("Called Credentials Provider!");
                throw new CredentialsNotAvailableException();
            }
        }, null);

        NetcdfDataset nc = NetcdfDataset.openDataset("http://myurl");
        nc.close();
    }

When I run this I get an error message:

    Server does not support byte Ranges
    at ucar.unidata.io.http.HTTPRandomAccessFile.<init>(HTTPRandomAccessFile.java:99)

which, having delved through the nj22 code, actually just means that
the call to get the value of the Accept-Ranges header does not return
what is expected.  I assume that the real reason that the call fails
is that the server requires authentication.  The simple
CredentialsProvider that I have written in the above code never gets
called.

Could anyone please shed some light on this, or perhaps provide a code
snippet of the right way to go about this?

Thanks very much,
Jon

On Nov 26, 2007 7:24 PM, John Caron <caron at unidata.ucar.edu> wrote:
> Hi Jon:
>
> ucar.nc2.dataset.HttpClientManager is in 2.2.22 release. I beleive it was added at 2.2.19.
>
>
> Jon Blower wrote:
> > Hi all,
> >
> > I'm trying to read data from an authenticated OPeNDAP server.  I've
> > found the page http://www.unidata.ucar.edu/software/netcdf-java/reference/HTTPauthentication.html,
> > which says that I should create a CredentialsProvider and register it
> > using ucar.nc2.dataset.HttpClientManager.init().  However, there is no
> > class called HttpClientManager in the ucar.nc2.dataset package, or
> > indeed anywhere in the nj22 distribution that I can see.
> >
> > What is the best way to read data from authenticated OPeNDAP servers?
> > I am using nj22 version 2.2.16.
> >
> > Thanks, Jon
> >
>



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