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https://issues.apache.org/jira/browse/NIFI-6204?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Mike Thomsen resolved NIFI-6204.
--------------------------------
Resolution: Fixed
Ran a simple flow based on this schema, and it worked just fine.
> Avro with a default field of type long fails with ClassCastException
> --------------------------------------------------------------------
>
> Key: NIFI-6204
> URL: https://issues.apache.org/jira/browse/NIFI-6204
> Project: Apache NiFi
> Issue Type: Bug
> Reporter: Lars Francke
> Priority: Minor
> Attachments: Avro-issue.xml, Screen Shot 2019-04-11 at 00.33.51.png,
> Screen Shot 2019-04-11 at 00.38.31.png
>
>
> I get this error:
> {code}org.apache.avro.file.DataFileWriter$AppendWriteException:
> java.lang.ClassCastException: java.lang.Integer cannot be cast to
> java.lang.Long{code}
> I've attached an example workflow plus screenshots.
> Basically: Converting a schema like this
> {code}
> {
> "name": "foobar",
> "type": "record",
> "fields": [
> { "name": "a", "type": "string" }
> ]
> }
> {code}
> into this
> {code}
> {
> "name": "foobar",
> "type": "record",
> "fields": [
> { "name": "a", "type": "string" },
> { "name": "b", "type": "long", "default": 100 }
> ]
> }
> {code}
> fails because of this snippet in {{AvroTypeUtil}}:
> {code}
> // see if the Avro schema has any fields that aren't in the
> RecordSchema, and if those fields have a default
> // value then we want to populate it in the GenericRecord being
> produced
> for (final Field field : avroSchema.getFields()) {
> final Optional<RecordField> recordField =
> recordSchema.getField(field.name());
> if (!recordField.isPresent() && rec.get(field.name()) == null &&
> field.defaultVal() != null) {
> rec.put(field.name(), field.defaultVal());
> }
> }
> {code}
> This relies on {{field.defaultVal()}} returning the correct type.
> The field that this relies on is a {{JsonNode}} from Jackson. So it parses
> the Schema and the "default" field is parsed into an {{IntNode}} which is
> then put into the record and that is not a Long so the cast fails when Avro
> tries to write it later.
> Now Jackson has no way of knowing that this is supposed to be a LongNode
> instead of an IntNode. I'm not sure if Avro should catch this or NiFi and I
> also have no good idea on how to fix this.
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