Re: Optional string in avro scheme

[Emre Sevinc]

Hello Dmitry,

Does the following SO answer help you:

 http://stackoverflow.com/a/27499930/236007


Kind regards,
Emre Sevinç


On Fri, May 15, 2015 at 9:44 AM, Dzmitry Hancharou <goncharo...@gmail.com>
wrote:

> Hello all,
>
> I want to convert json with optional string field into binary avro file.
>
> The following scheme is used:
> Optional.avsc:
>     {
>         "namespace": "Namespace",
>         "type": "record",
>         "name": "Optional",
>         "fields": [
>             {
>                 "name": "opt",
>                 "type": ["null", "string"],
>                 "default": null
>             },
>             {
>                 "name": "req",
>                 "type": "string"
>             }
>         ]
>     }
>
> optional.json: {"req": "xxx"}
>
> When I run "java -jar avro-tools-1.7.7.jar fromjson --schema-file
> Optional.avsc optional.json > optional.avro", get exception:
> Exception in thread "main" org.apache.avro.AvroTypeException: Expected
> field name not found: opt
> at org.apache.avro.io.JsonDecoder.doAction(JsonDecoder.java:477)
> at org.apache.avro.io.parsing.Parser.advance(Parser.java:88)
> at org.apache.avro.io.JsonDecoder.advance(JsonDecoder.java:139)
> at org.apache.avro.io.JsonDecoder.readIndex(JsonDecoder.java:429)
> at org.apache.avro.io.ResolvingDecoder.doAction(ResolvingDecoder.java:290)
> at org.apache.avro.io.parsing.Parser.advance(Parser.java:88)
> at org.apache.avro.io.ResolvingDecoder.readIndex(ResolvingDecoder.java:267)
> at
> org.apache.avro.generic.GenericDatumReader.read(GenericDatumReader.java:155)
> at
> org.apache.avro.generic.GenericDatumReader.readField(GenericDatumReader.java:193)
> at
> org.apache.avro.generic.GenericDatumReader.readRecord(GenericDatumReader.java:183)
> at
> org.apache.avro.generic.GenericDatumReader.read(GenericDatumReader.java:151)
> at
> org.apache.avro.generic.GenericDatumReader.read(GenericDatumReader.java:142)
> at org.apache.avro.tool.DataFileWriteTool.run(DataFileWriteTool.java:99)
> at org.apache.avro.tool.Main.run(Main.java:84)
> at org.apache.avro.tool.Main.main(Main.java:73)
>
> When I change optional.json to {"opt": "yyy", "req": "xxx"}, I get
> Exception in thread "main" org.apache.avro.AvroTypeException: Expected
> start-union. Got VALUE_STRING
> at org.apache.avro.io.JsonDecoder.error(JsonDecoder.java:697)
> at org.apache.avro.io.JsonDecoder.readIndex(JsonDecoder.java:441)
> at org.apache.avro.io.ResolvingDecoder.doAction(ResolvingDecoder.java:290)
> at org.apache.avro.io.parsing.Parser.advance(Parser.java:88)
> at org.apache.avro.io.ResolvingDecoder.readIndex(ResolvingDecoder.java:267)
> at
> org.apache.avro.generic.GenericDatumReader.read(GenericDatumReader.java:155)
> at
> org.apache.avro.generic.GenericDatumReader.readField(GenericDatumReader.java:193)
> at
> org.apache.avro.generic.GenericDatumReader.readRecord(GenericDatumReader.java:183)
> at
> org.apache.avro.generic.GenericDatumReader.read(GenericDatumReader.java:151)
> at
> org.apache.avro.generic.GenericDatumReader.read(GenericDatumReader.java:142)
> at org.apache.avro.tool.DataFileWriteTool.run(DataFileWriteTool.java:99)
> at org.apache.avro.tool.Main.run(Main.java:84)
> at org.apache.avro.tool.Main.main(Main.java:73)
>
> What I'm doing wrong?
>
> Thanks,
> Dmitry
>
>
>


-- 
Emre Sevinc