Hi Andy,
Can you check that you are using namespaces consistently? I noticed in your
exception message that the Teacher record is in namespace com.model, but
your schema above declares it as being in namespace com.my.model.
This suggests that perhaps something is broken in your build process — for
example, perhaps you are using code generated from an old version of the
schema?
Martin
On 2 December 2013 20:06, Lewis John Mcgibbney <lewis.mcgibb...@gmail.com>wrote:
> Hi,
> I've never experienced this before but I would suggestb setting a default
> value for the UNION {"name": "other", "type": ["null", "Teacher",
> "Student"]}
> Lewis
>
>
> On Mon, Dec 2, 2013 at 8:00 PM, andy36 <andyfi...@gmail.com> wrote:
>
>> I am using [Apache Avro][1] for object serialization.
>>
>> I have one Avro schema for `School` object:
>>
>> {"namespace": "com.my.model",
>> "type": "record",
>> "name": "School",
>> "fields": [
>> {"name": "sid", "type": "int"},
>> {"name": "size", "type": "long"},
>> {"name": "other", "type": ["null", "Teacher", "Student"]}
>> ]
>> }
>>
>> As you see above, the `"other"` field holds an **union data type**, it
>> could
>> be either `null` or a `Teacher` instance or a `Student` instance.
>>
>> The **Teacher** object schema:
>>
>> {"namespace": "com.my.model",
>> "type": "record",
>> "name": "Teacher",
>> "fields": [
>> {"name": "isMale", "type": "boolean"}
>> ]
>> }
>>
>> The **Student** object schema:
>>
>> {"namespace": "com.my.model",
>> "type": "record",
>> "name": "Student",
>> "fields": [
>> {"name": "age", "type": "int"}
>> ]
>> }
>>
>> I compiled above schemas with Avro tool & Avro generated all the Java
>> classes for me automatically.
>>
>> Then, in my java program I am creating `School` instance in the following
>> way:
>>
>> School school = new School();
>> school.setSid(3);
>> school.setSize(2000);
>>
>> //create a student object
>> Student student = new Student();
>> student.setAge(18);
>>
>> //set student into school instance
>> school.setOther(student);
>>
>> As you see above, the school instance's `other` field holds a student
>> object. When I compile my code, however I got the
>> **UnresolvedUnionException** . It complains about the **union data type**
>> for the `other` field of `School` schema. Seems it can not resolve the
>> `student` I set to `school` in my Java code. Why is this exception ?
>> Stacktrace is:
>>
>> org.apache.avro.UnresolvedUnionException: Not in union
>>
>> ["null",{"type":"record","name":"Student","namespace":"com.my.model","fields":[{"name":"age","type":"long"}]},{"type":"record","name":"Teacher","namespace":"com.model","fields":[{"name":"isMale","type":"boolean"}]}]:
>> false
>> at
>> org.apache.avro.generic.GenericData.resolveUnion(GenericData.java:561)
>> at
>>
>> org.apache.avro.generic.GenericDatumWriter.resolveUnion(GenericDatumWriter.java:144)
>> at
>>
>> org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:71)
>> at
>>
>> org.apache.avro.generic.GenericDatumWriter.writeRecord(GenericDatumWriter.java:106)
>> at
>>
>> org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:66)
>> at
>>
>> org.apache.avro.generic.GenericDatumWriter.writeArray(GenericDatumWriter.java:131)
>> at
>>
>> org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:68)
>> at
>>
>> org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:73)
>> at
>>
>> org.apache.avro.generic.GenericDatumWriter.writeRecord(GenericDatumWriter.java:106)
>> at
>>
>> org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:66)
>> at
>>
>> org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:58)
>>
>>
>> [1]: http://avro.apache.org/docs/1.7.4/gettingstartedjava.html
>>
>>
>>
>> --
>> View this message in context:
>> http://apache-avro.679487.n3.nabble.com/Apache-Avro-UnresolvedUnionException-when-using-union-data-type-tp4028641.html
>> Sent from the Avro - Users mailing list archive at Nabble.com.
>>
>
>
>
> --
> *Lewis*
>
