serialization - How to define Avro union in java -


i have defined avro schema composed of record contains union of 2 (or more) different records such as:

{   "type":"record",   "name":"mycompositerecord",   "fields":   [     {"name":"somecommondata","type":"string"},     {"name":"morecommondata","type":"float"},     {"name":"compositerecord","type":       [         {           "type":"record",           "name":"firstoption",           "fields":           [             {"name":"x","type":"string"},             {"name":"y","type":"long"}           ]         },         {           "type":"record",           "name":"secondoption",           "fields":           [             {"name":"z","type":"int"},             {"name":"w","type":"float"},             {"name":"m","type":"double"},             {"name":"l","type":"boolean"}           ]         }       ]     }   ] }

it doesn't clear hope idea: have record composed of data ("somecommondata" , "morecommondata") , union of 2 different types of records ("firstoption" , "secondoption"). @ serialization/deserialization time should able create either 1 of 2 sub-records , serialize "mycompositerecord".

i haven't tried generating code schema since i'm planning on using generic records. however, i'm not sure if , how such generic records can serialized. can't find example online. i'm going use java serialized/deserialize. able create writer/reader schema follows:

schema.parser parser = new schema.parser(); schema schema = parser.parse(composite_schema); datumwriter<genericrecord> writer = new genericdatumwriter<>(schema); datumreader<genericrecord> reader = new genericdatumreader<>(schema); genericrecord datum = new genericdata.record(schema);

any ideas on how proceed here build record?

thanks

basically union no different setting other field:

genericrecord datum = new genericdata.record(schema);  datum.set(1, data);

where 1 union field number , data value being set.

if @ getdefaultvalue in avroeditor - helper, see default values use each avro type. arrays must implement genericarray.


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