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https://issues.apache.org/jira/browse/FLINK-2023?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14547747#comment-14547747
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PJ Van Aeken commented on FLINK-2023:
-------------------------------------
So this works, I'm just not entirely sure this is what you meant :
I extended the java Gelly API with a method like the one below so I can
explicitely pass all TypeInformation:
public <NV> Graph<K, NV, EV> mapVertices(final MapFunction<Vertex<K, VV>,
NV> mapper, TypeInformation<K> keyType, TypeInformation<NV> valueType,
TypeInformation<Vertex<K, NV>> returnType) {
DataSet<Vertex<K, NV>> mappedVertices = vertices.map(
new MapFunction<Vertex<K, VV>, Vertex<K, NV>>() {
public Vertex<K, NV> map(Vertex<K, VV> value) throws
Exception {
return new Vertex<K, NV>(value.f0, mapper.map(value));
}
}).returns(returnType);
return new Graph<K, NV, EV>(mappedVertices, this.edges, this.context);
}
I then call this method in the Scala API like this :
new Graph[K, NV, EV](jgraph.mapVertices[NV](
mapper,
createTypeInformation[K],
createTypeInformation[NV],
createTypeInformation[Vertex[K, NV]]
))
> TypeExtractor does not work for (some) Scala Classes
> ----------------------------------------------------
>
> Key: FLINK-2023
> URL: https://issues.apache.org/jira/browse/FLINK-2023
> Project: Flink
> Issue Type: Bug
> Components: Type Serialization System
> Reporter: Aljoscha Krettek
>
> [~vanaepi] discovered some problems while working on the Scala Gelly API
> where, for example, a Scala MapFunction can not be correctly analyzed by the
> type extractor. For example, generic types will not be correctly detected.
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