Re: [netcdf-java] Fwd: How to use the Java Api

Greetings Shashi!

netCDF-Java uses a wrapper around the apache http client library,
called httpservices.
While httpservices knows about the apache http client, it does not know
about the hadoop http client, which is the cause of the error you are
seeing.

Dennis - do you know what it would take to support http access to hadoop (
hdfs) via httpservices?

Sean


On Sat, Jul 2, 2016 at 1:37 AM, shashi kumar <shashi.fengshui@xxxxxxxxx>
wrote:

> Dear Sean,
>
> I am getting the below error when i use the netcdf-all jar on my hadoop
> project for analysing the nc file . Kindly help me in identifying the issue
> .
>
> ucar.httpservices.HTTPException: ucar.httpservices.HTTPException: 
> org.apache.http.conn.UnsupportedSchemeException: hdfs protocol is not 
> supported
>       at ucar.httpservices.HTTPMethod.execute(HTTPMethod.java:335)
>       at ucar.nc2.dataset.NetcdfDataset.checkIfDods(NetcdfDataset.java:864)
>       at 
> ucar.nc2.dataset.NetcdfDataset.disambiguateHttp(NetcdfDataset.java:820)
>       at 
> ucar.nc2.dataset.NetcdfDataset.openOrAcquireFile(NetcdfDataset.java:706)
>       at ucar.nc2.dataset.NetcdfDataset.openDataset(NetcdfDataset.java:427)
>       at ucar.nc2.dataset.NetcdfDataset.acquireDataset(NetcdfDataset.java:528)
>       at ucar.nc2.dt.grid.GridDataset.open(GridDataset.java:117)
>       at ucar.nc2.dt.grid.GridDataset.open(GridDataset.java:103)
>       at 
> tvl.bd.climate.recordreader.MyRecordReader.initialize(MyRecordReader.java:46)
>       at 
> org.apache.hadoop.mapred.MapTask$NewTrackingRecordReader.initialize(MapTask.java:521)
>       at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:763)
>       at org.apache.hadoop.mapred.MapTask.run(MapTask.java:364)
>       at org.apache.hadoop.mapred.Child$4.run(Child.java:255)
>       at java.security.AccessController.doPrivileged(Native Method)
>       at javax.security.auth.Subject.doAs(Subject.java:422)
>       at 
> org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1190)
>       at org.apache.hadoop.mapred.Child.main(Child.java:249)
> Caused by: ucar.httpservices.HTTPException: 
> org.apache.http.conn.UnsupportedSchemeException: hdfs protocol is not 
> supported
>       at ucar.httpservices.HTTPSession.execute(HTTPSession.java:1136)
>       at ucar.httpservices.HTTPMethod.execute(HTTPMethod.java:326)
>       ... 16 more
> Caused by: org.apache.http.conn.UnsupportedSchemeException: hdfs protocol is 
> not supported
>       at 
> org.apache.http.impl.conn.DefaultHttpClientConnectionOperator.connect(DefaultHttpClientConnectionOperator.java:108)
>       at 
> org.apache.http.impl.conn.PoolingHttpClientConnectionManager.connect(PoolingHttpClientConnectionManager.java:353)
>       at 
> org.apache.http.impl.execchain.MainClientExec.establishRoute(MainClientExec.java:380)
>       at 
> org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:236)
>       at 
> org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:184)
>       at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:88)
>       at 
> org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:110)
>       at 
> org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:184)
>       at 
> org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:71)
>       at ucar.httpservices.HTTPSession.execute(HTTPSession.java:1134)
>
>
> Regards,
>
> Sashi
>
>
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