Re: java.lang.AbstractMethodError when implementing KafkaSerializationSchema

Posted by Piotr Nowojski-3 on
URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/java-lang-AbstractMethodError-when-implementing-KafkaSerializationSchema-tp35362p35441.html

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

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

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[hidden email]