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Avro >> mail # user >> Incorrect Json schema generated for @java_class


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avronewbie 2013-02-28, 03:18
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Doug Cutting 2013-02-28, 17:19
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Alexandre Normand 2013-02-28, 17:25
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Doug Cutting 2013-02-28, 18:04
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Alexandre Normand 2013-02-28, 18:36
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Re: Incorrect Json schema generated for @java_class
If you cannot use ReflectDatumReader and ReflectDatumWriter then
perhaps we could move the readString() and writeString()
implementations from these to SpecificData.  One can imagine also
wishing to, e.g., specify the collection class used for arrays and
maps via the java-class schema property with specific data.  The
reflect package is more about automatically inferring schemas through
introspection.  That's not the case here, rather this is just
permitting more control over what classes are used to implement one's
schemas, which seems reasonably within the scope of specific.

Doug

On Thu, Feb 28, 2013 at 10:36 AM, Alexandre Normand
<[EMAIL PROTECTED]> wrote:
> I agree with the SpecificCompiler#getStringType() change. I actually have an
> early draft patch that has this change. As for using the ReflectDatum
> Reader/Writer, I guess that might be sufficient for some use cases but,
> unfortunately, it isn't for mine ;). We're using kiji
> (https://github.com/kijiproject) and I don't have control over the
> Reader/Writer implementation being used.
>
> I don't want to dirty the Generic/Specific reader/writers but it might be
> some desirable feature to support JDK classes like the
> BigDecimal/BigInteger?
>
> --
> Alex
>
> On Thursday, February 28, 2013 at 10:04 AM, Doug Cutting wrote:
>
> You could get the specific compiler to emit the desired type by
> modifying the method SpecificCompiler#getStringType() to take the
> Schema as a parameter and, if it has a java-class attribute, return
> that. Then things should work so long as you use ReflectDatumReader
> and ReflectDatumWriter. Would that suffice?
>
> Doug
>
> On Thu, Feb 28, 2013 at 9:25 AM, Alexandre Normand
> <[EMAIL PROTECTED]> wrote:
>
> Hey Doug,
> I was also wondering about something related. In reflection, we can use the
> java-class property to define the java class for stringable types. Could we
> find a way to bring some of this to the Specific generated classes so that a
> stringable type (I'm specifically thinking of BigDecimal and BigInteger)
> could be exposed as the java-class type instead of Strings? I started
> looking into this and there seem to be two possibilities, none of which I'm
> terribly excited about:
>
> 1. Use some reflection to invoke the string constructor for the
> java-class…but that seems dirty as the Specific API probably shouldn't do
> reflection, right?
> 2. Handle a very specific list of java-class types (such as BigDecimal and
> BigInteger) and have code that deals specifically with these in
> Reader/Writer.
>
> Thoughts?
> --
> Alex
>
> On Thursday, February 28, 2013 at 9:19 AM, Doug Cutting wrote:
>
> Annotation names in IDL are copied directly to schema properties with
> the same names.
>
> The bug is in the IDL documentation, which uses the annotation
> @java_class in an example, which is meaningless. The Java
> implementation requires the "java-class" schema property, so the
> annotation used should be @java-class.
>
> I filed an issue in Jira for this.
>
> https://issues.apache.org/jira/browse/AVRO-1264
>
> Doug
>
> On Wed, Feb 27, 2013 at 7:18 PM, avronewbie <[EMAIL PROTECTED]> wrote:
>
> For the IDL field:
>
> @java_class("java.util.ArrayList") array<int> arrayOfInts;
>
> the JSON schema generated by the avro-maven-plugin is
>
> {\"name\":\"arrayOfInts\",\"type\":{\"type\":\"array\",\"items\":\"int\",\"java_class\":\"java.util.ArrayList\"}}
>
> Shouldn't it be generated in JSON as java-class (with hypen instead of
> underscore) instead of java_class? Because of this reading from avro file is
> not working.
>
>
>
>
> --
> View this message in context:
> http://apache-avro.679487.n3.nabble.com/Incorrect-Json-schema-generated-for-java-class-tp4026430.html
> Sent from the Avro - Users mailing list archive at Nabble.com.
>
>
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Alexandre Normand 2013-02-28, 22:08
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avronewbie 2013-02-28, 20:10
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Doug Cutting 2013-02-28, 21:51