[KAFKA-4100] Connect Struct schemas built using SchemaBuilder with no fields cause NPE in Struct constructor

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 0.10.0.1
• Fix Version/s: 0.10.1.0
• Component/s: connect
• Assignee: Shikhar Bhushan
• Reporter: Shikhar Bhushan
• Created: 29/Aug/16 21:53
• Updated: 30/Aug/16 02:09
• Resolved: 30/Aug/16 02:09

Description

Avro records can legitimately have 0 fields (though arguable how useful that is).

When using the Confluent Schema Registry's AvroConverter with such a schema,

java.lang.NullPointerException
	at org.apache.kafka.connect.data.Struct.<init>(Struct.java:56)
	at io.confluent.connect.avro.AvroData.toConnectData(AvroData.java:980)
	at io.confluent.connect.avro.AvroData.toConnectData(AvroData.java:782)
	at io.confluent.connect.avro.AvroConverter.toConnectData(AvroConverter.java:103)
	at org.apache.kafka.connect.runtime.WorkerSinkTask.convertMessages(WorkerSinkTask.java:358)
	at org.apache.kafka.connect.runtime.WorkerSinkTask.poll(WorkerSinkTask.java:227)
	at org.apache.kafka.connect.runtime.WorkerSinkTask.iteration(WorkerSinkTask.java:171)
	at org.apache.kafka.connect.runtime.WorkerSinkTask.execute(WorkerSinkTask.java:143)
	at org.apache.kafka.connect.runtime.WorkerTask.doRun(WorkerTask.java:140)
	at org.apache.kafka.connect.runtime.WorkerTask.run(WorkerTask.java:175)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
	at java.util.concurrent.FutureTask.run(FutureTask.java:262)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:745)

This is because it is using the SchemaBuilder to create the Struct schema, which provides a field(..) builder for each field. If there are no fields, the list stays as null.

Issue Links

• links to: GitHub Pull Request #1800