为二进制值设置 VALUE_SERIALIZER_CLASS_CONFIG

Question

I get this error when I attempt to execute my Kafka producer application:

Exception in thread "main" org.apache.kafka.common.errors.SerializationException: Can't convert value of class [B to class org.apache.kafka.common.serialization.IntegerSerializer specified in value.serializer Caused by: java.lang.ClassCastException: [B cannot be cast to java.lang.Integer at org.apache.kafka.common.serialization.IntegerSerializer.serialize(IntegerSerializer.java:19) at org.apache.kafka.common.serialization.Serializer.serialize(Serializer.java:62) at org.apache.kafka.clients.producer.KafkaProducer.doSend(KafkaProducer.java:894) at org.apache.kafka.clients.producer.KafkaProduc er.send(KafkaProducer.java:856) at org.apache.kafka.clients.producer.KafkaProducer.send(KafkaProducer.java:743) at com.cme.pe.ProducerDemo.main(ProducerDemo.java:50)

The issue is that my VALUE_SERIALIZER_CLASS_CONFIG property is StringSerializer but my KafkaProducer and Producer record have a binary value

properties.setProperty(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());

KafkaProducer<String, byte[]> producer = new KafkaProducer<String, byte[]>(properties);
        
ProducerRecord<String, byte[]> record = new ProducerRecord<String, byte[]>("foo", allBytes);

What should my VALUE_SERIALIZER_CLASS_CONFIG be set to for this?

Answer 1

ByteArraySerializer.class.getName()

The line should be

properties.setProperty(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, ByteArraySerializer.class.getName());