HI avro-users,

I'm having issues with SortedKeyValueFile.Reader. Even though the return
type of get is a specific record type, the actual instance returned has
type GenericRecord. How do I convert this GenericRecord into an instance of
my specific record?

Looking at the source code SortedKeyValueFile is using the Generic
interface to read the data. But the return type for get is V where I have
set V to be a specific record. e.g

SortedKeyValueFile.Reader<CharSequence, GraphNodeData> where GraphNodeData
is one of my avro records.

I don't understand how  this code compiles since the return type is
V=GraphNodeData and a GenericRecord can't be cast to a GraphNodeData.

Thoughts?

Thanks
J

A GenericDatumReader will never return a specific record.  Perhaps
this code should use ReflectDatumReader (which will return a java
class if the named class is loaded or else GenericRecord).  The
changes will be deeper, since this builds on AvroKeyValue which also
assumes generic, so I can't tell at a glance how difficult this would
be.

Doug

On Sat, Dec 15, 2012 at 11:06 PM, Jeremy Lewi <[EMAIL PROTECTED]> wrote:
> HI avro-users,
>
> I'm having issues with SortedKeyValueFile.Reader. Even though the return
> type of get is a specific record type, the actual instance returned has type
> GenericRecord. How do I convert this GenericRecord into an instance of my
> specific record?
>
> Looking at the source code SortedKeyValueFile is using the Generic interface
> to read the data. But the return type for get is V where I have set V to be
> a specific record. e.g
>
> SortedKeyValueFile.Reader<CharSequence, GraphNodeData> where GraphNodeData
> is one of my avro records.
>
> I don't understand how  this code compiles since the return type is
> V=GraphNodeData and a GenericRecord can't be cast to a GraphNodeData.
>
> Thoughts?
>
> Thanks
> J

Thanks Doug. I worked around it by just encoding it and then redecoding it
using specific record.

J
On Mon, Dec 17, 2012 at 10:31 AM, Doug Cutting <[EMAIL PROTECTED]> wrote:

> A GenericDatumReader will never return a specific record.  Perhaps
> this code should use ReflectDatumReader (which will return a java
> class if the named class is loaded or else GenericRecord).  The
> changes will be deeper, since this builds on AvroKeyValue which also
> assumes generic, so I can't tell at a glance how difficult this would
> be.
>
> Doug
>
> On Sat, Dec 15, 2012 at 11:06 PM, Jeremy Lewi <[EMAIL PROTECTED]> wrote:
> > HI avro-users,
> >
> > I'm having issues with SortedKeyValueFile.Reader. Even though the return
> > type of get is a specific record type, the actual instance returned has
> type
> > GenericRecord. How do I convert this GenericRecord into an instance of my
> > specific record?
> >
> > Looking at the source code SortedKeyValueFile is using the Generic
> interface
> > to read the data. But the return type for get is V where I have set V to
> be
> > a specific record. e.g
> >
> > SortedKeyValueFile.Reader<CharSequence, GraphNodeData> where
> GraphNodeData
> > is one of my avro records.
> >
> > I don't understand how  this code compiles since the return type is
> > V=GraphNodeData and a GenericRecord can't be cast to a GraphNodeData.
> >
> > Thoughts?
> >
> > Thanks
> > J
>