Generated Java code fails with union containing logical type

[Ross Black]

Hi,

I just encountered an issue that I suspect is a bug when using a logical
type within a union.
I am using Avro 1.8.1 with JDK8.


My schema is:
    {
      "type": "record",
      "name": "RecordV1",
      "namespace": "org.brasslock.event",
      "fields": [
        { "name": "first", "type": ["null", {"type": "long",
"logicalType":"timestamp-millis"}]}
      ]
    }

The avro compiler generates a field using the relevant joda class:
    public org.joda.time.DateTime first


Running the following code to perform encoding:
        final RecordV1 record = new
RecordV1(DateTime.parse("2016-07-29T10:15:30.00Z"));
        final DatumWriter<RecordV1> datumWriter = new
SpecificDatumWriter<>(record.getSchema());
        final ByteArrayOutputStream stream = new
ByteArrayOutputStream(8192);
        final BinaryEncoder encoder =
EncoderFactory.get().directBinaryEncoder(stream, null);
        datumWriter.write(record, encoder);
        encoder.flush();
        final byte[] bytes = stream.toByteArray();

fails with the exception stacktrace:
 org.apache.avro.AvroRuntimeException: Unknown datum type
org.joda.time.DateTime: 2016-07-29T10:15:30.000Z

    at
org.apache.avro.generic.GenericData.getSchemaName(GenericData.java:741)
    at
org.apache.avro.specific.SpecificData.getSchemaName(SpecificData.java:293)
    at
org.apache.avro.generic.GenericData.resolveUnion(GenericData.java:706)
    at
org.apache.avro.generic.GenericDatumWriter.resolveUnion(GenericDatumWriter.java:192)
    at
org.apache.avro.generic.GenericDatumWriter.writeWithoutConversion(GenericDatumWriter.java:110)
    at
org.apache.avro.specific.SpecificDatumWriter.writeField(SpecificDatumWriter.java:87)
    at
org.apache.avro.generic.GenericDatumWriter.writeRecord(GenericDatumWriter.java:143)
    at
org.apache.avro.generic.GenericDatumWriter.writeWithoutConversion(GenericDatumWriter.java:105)
    at
org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:73)
    at
org.apache.avro.generic.GenericDatumWriter.write(GenericDatumWriter.java:60)
    at
org.brasslock.avro.compiler.GeneratedRecordTest.shouldEncodeLogicalTypeInUnion(GeneratedRecordTest.java:82)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at
org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
    at
org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at
org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    at
org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at
org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    at
org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at
com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:117)
    at
com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:42)
    at
com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:253)
    at
com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:84)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)



The failure can be fixed by explicitly adding the relevant conversion(s) to
DatumWriter / SpecificData:
        final RecordV1 record = new
RecordV1(DateTime.parse("2007-12-03T10:15:30.00Z"));
        final SpecificData specificData = new SpecificData();
        specificData.addLogicalTypeConversion(new
TimeConversions.TimestampConversion());
        final DatumWriter<RecordV1> datumWriter = new
SpecificDatumWriter<>(record.getSchema(), specificData);
        final ByteArrayOutputStream stream = new
ByteArrayOutputStream(AvroUtil.DEFAULT_BUFFER_SIZE);
        final BinaryEncoder encoder =
EncoderFactory.get().directBinaryEncoder(stream, null);
        datumWriter.write(record, encoder);
        encoder.flush();
        final byte[] bytes = stream.toByteArray();


Is this expected behaviour?  To me it is not particularly obvious that
generated code does not work with a standard datum writer.


Thanks,
Ross