Re: java.lang.AbstractMethodError when implementing KafkaSerializationSchema

Posted by Aljoscha Krettek on
URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/java-lang-AbstractMethodError-when-implementing-KafkaSerializationSchema-tp35362p35459.html

I think what might be happening is that you're mixing dependencies from
the flink-sql-connector-kafka and the proper flink-connector-kafka that
should be used with the DataStream API. Could that be the case?

Best,
Aljoscha

On 25.05.20 19:18, Piotr Nowojski wrote:

> Hi,
>
> It would be helpful if you could provide full stack trace, what Flink version and which Kafka connector version are you using?
>
> It sounds like either a dependency convergence error (mixing Kafka dependencies/various versions of flink-connector-kafka inside a single job/jar) or some shading issue. Can you check your project for such issues (`mvn dependency:tree` command [1]).
>
> Also what’s a bit suspicious for me is the return type:
>
>> Lorg/apache/flink/kafka/shaded/org/apache/kafka/clients/producer/ProducerRecord;
>
> I’m not sure, but I was not aware that we are shading Kafka dependency in our connectors? Are you manually shading something?
>
> Piotrek
>
> [1] https://maven.apache.org/plugins/maven-dependency-plugin/examples/resolving-conflicts-using-the-dependency-tree.html <https://maven.apache.org/plugins/maven-dependency-plugin/examples/resolving-conflicts-using-the-dependency-tree.html>
>
>> On 22 May 2020, at 15:34, [hidden email] wrote:
>>
>>
>> public class MyKafkaSerializationSchema implements KafkaSerializationSchema<Tuple2<String, String>> {
>>      @Override
>>      public ProducerRecord<byte[], byte[]> serialize(Tuple2<String, String> o, @Nullable Long aLong) {
>>          ProducerRecord<byte[], byte[]> record = new ProducerRecord<>(o.f0,
>>              o.f1.getBytes(StandardCharsets.UTF_8));
>>          return record;
>>      }
>> }
>> FlinkKafkaProducer<Tuple2<String, String>> producer = new FlinkKafkaProducer<Tuple2<String, String>>(
>>      "default", new MyKafkaSerializationSchema(),
>>      prop2,Semantic.EXACTLY_ONCE);
>>
>> But there's  error when runnng：
>>
>> java.lang.AbstractMethodError: com.geekplus.flinketl.schema.MyKafkaSerializationSchema.serialize(Ljava/lang/Object;Ljava/lang/Long;)Lorg/apache/flink/kafka/shaded/org/apache/kafka/clients/producer/ProducerRecord;
>>
>> Any suggestion on this？
>>
>> Thanks，
>> Lei
>> [hidden email] <mailto:[hidden email]>
>