Hi there, I'm using Avro 1.8.0, and I'm not sure why one of my
compatibility tests is failing.
I have two schemas:
V1:
{
"namespace" : "io.igx.android",
"type" : "record",
"name" : "Sensor",
"fields" : [
{"name":"id","type":"string"},
{"name":"temperature", "type":"float"},
{"name":"acceleration", "type":"float","default":0.0},
{"name":"velocity","type":"float","default":0.0},
{"name":"accelerometer","type":[
"null",{
"type":"array",
"items":"float"
}
]},
{"name":"magneticField","type":[
"null",{
"type":"array",
"items":"float"
}
]},
{"name":"orientation","type":[
"null",{
"type":"array",
"items":"float"
}
],"default":"null"}
]
}
V2:
{
"namespace" : "io.igx.android",
"type" : "record",
"name" : "Sensor",
"fields" : [
{"name":"id","type":"string"},
{"name":"temperature", "type":"float", "default":0.0},
{"name":"acceleration", "type":"float","default":0.0},
{"name":"velocity","type":"float","default":0.0},
{"name":"accelerometer","type":[
"null",{
"type":"array",
"items":"float"
}
]},
{"name":"magneticField","type":[
"null",{
"type":"array",
"items":"float"
}
]}
]
}
As you can see the only difference between those two is that one of the
arrays is removed from V2, and I've added a default value to a property on
V2.
If I run:
SchemaCompatibility.checkReaderWriterCompatibility(load("schemas/sensor_v2.avsc"),load("schemas/sensor_v1.avsc")).getType()
It prints out that data written in v2 should be able to be read by v1,
which seems logical
But when I try to deserialize data from v2 using v1 reader I get an error:
Sensor v1Fromv2 = deserialize(v2Bytes,v1.getSchema(),v2.getSchema());
private <T> T deserialize(byte[] bytes, Schema reader, Schema writer)
throws Exception{
DatumReader datumReader = new SpecificDatumReader<>(writer,reader);
Decoder decoder = DecoderFactory.get().binaryDecoder(bytes,null);
return (T) datumReader.read(null,decoder);
}
org.apache.avro.AvroTypeException: Non-null default value for null type:
"null"
Not sure why is the deserialization not working if the compatibility check
passes
Any ideas?
Regards
