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https://issues.apache.org/jira/browse/AVRO-2449?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16881067#comment-16881067
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Ryan Skraba commented on AVRO-2449:
-----------------------------------
For info, there's been some effort put into removing jackson classes from the
public API: AVRO-1605, AVRO-1605
Does generated code count as part of the public API? It seems to me that it
would... Is there another solution that could help improve the out-of-the-box
jackson serialization? Making these annotations opt-in or configurable, or a
velocity extension for annotating methods that do not contain record-specific
data?
> Velocity Templates do not allow for Jackson unmarhsalling to JSON
> -----------------------------------------------------------------
>
> Key: AVRO-2449
> URL: https://issues.apache.org/jira/browse/AVRO-2449
> Project: Apache Avro
> Issue Type: Improvement
> Components: java
> Affects Versions: 1.9.0
> Reporter: Jeff
> Priority: Minor
>
> *This applies to working in Kotlin* _Havent tested in java_
> When using java classes auto-generated by the Avro-tools or the Gradle tasks
> (in my case) the output classes are not out of the box compatible with
> serializing to JSON.
> I detailed my issues in this stack post:
> [https://stackoverflow.com/questions/56742226/avro-generated-class-issue-with-json-conversion-kotlin]
> Specifically it appears that the two calls:
>
> {code:java}
> public org.apache.avro.specific.SpecificData getSpecificData() { return
> MODEL$; }
> public org.apache.avro.Schema getSchema() { return SCHEMA$; }
> {code}
>
> Are at issue - when I attempt to convert one of these records into Json using
> ObjectMapper.
> So there are two approaches I've come up with:
> 1) To create a Mixin for Jackson:
> {code:java}
> abstract class AvroMixIn {
> @JsonIgnore
> abstract fun getSchema(): org.apache.avro.Schema
> @JsonIgnore
> abstract fun getSpecificData() : org.apache.avro.specific.SpecificData
> }{code}
> And then I can apply this to the objet mapper (in a lazy way to all objects)
> {code:java}
> // Register the global object mapper to use the java time module (i think
> this is done elsewhere already) and to use the mixin to make it easy to
> jackson decode Avro stuff
> objectMapper
> .registerModule(JavaTimeModule())
> .addMixIn(Object::class.java, AvroMixIn::class.java)
> {code}
> The alternative would be to modify the velocity templates (which I also did)
> to add a
> {code:java}
> @com.fasterxml.jackson.annotation.JsonIgnore
> {code}
> annotation in front of the *getSpecificData* and *getSchema* calls
>
> As I'm pretty sure Jackson is a dependency of this project I'm wondering if
> its a reasonable consideration to modify the templates to add the
> *@JsonIgnore* annotation to make it easy to serailize/unserialze data right
> out of the box.
>
>
>
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