kafka streams processor Api to deserialize a avro record

Question

I am streaming the real time data from Kafka. But the data is in Avro format. Unable to deserialize as Json. Iam using Kafka Stream Low level Processor API. How to deserialize Avro record?

def orderStreamData(builder: KStreamBuilder, inTopic: String, outTopic: String): TopologyBuilder = {
    builder
      .addSource("source1", stringDe, stringDe, inTopic)//adding source topic
      //now adding processor class using ProcessSupplier
      .addProcessor("order", new ProcessorSupplier[String, String] {
      override def get(): Processor[String, String] = new ProcessorImpl
    }, "source1")
      //adding local state store for stateful operations
      .addStateStore(Stores.create("tester").withStringKeys.withStringValues.inMemory.build, "order")
      //adding destination topic for the processed data to go
      .addSink("sink", outTopic, stringSer, stringSer, "order")
  }

class ProcessorImpl extends AbstractProcessor[String, String]{

  var keyValueStore: KeyValueStore[String, String] = _
  var processorContext: ProcessorContext = _

  override def init(context: ProcessorContext): Unit = {
    processorContext = context
    processorContext.schedule(10000L)
    keyValueStore = processorContext.getStateStore("tester").asInstanceOf[KeyValueStore[String, String]]
    Objects.requireNonNull(keyValueStore, "State Store can't be null")
  }
/**
  * here logic is implemented
  * every value for a key must be greater than the previous value
  * */
  override def process(key: String, value: String): Unit = {
    //accessing local state store for last value saved for this key

  }
}

Answer 1

@Override
  public T deserialize(String inTopic, byte[] data) {
    try {
      T result = null; // Intialize result to null
  if (data != null) {

    DatumReader<GenericRecord> datumReader =
        new SpecificDatumReader<>(targetType.newInstance().getSchema());
    Decoder decoder = DecoderFactory.get().binaryDecoder(data, null);

    result = (T) datumReader.read(null, decoder);
    LOGGER.debug("deserialized data='{}'", result);
  }
  return result;
} catch (Exception ex) {
  throw new SerializationException("can not deserialize"+data+"exception"+ex);
}

}