com.networknt.kafka.common.AbstractAvroSerializer Maven / Gradle / Ivy

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package com.networknt.kafka.common;

import io.confluent.kafka.schemaregistry.client.rest.exceptions.RestClientException;
import org.apache.avro.Schema;
import org.apache.avro.generic.GenericDatumWriter;
import org.apache.avro.io.BinaryEncoder;
import org.apache.avro.io.DatumWriter;
import org.apache.avro.io.EncoderFactory;
import org.apache.avro.specific.SpecificDatumWriter;
import org.apache.avro.specific.SpecificRecord;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;

public abstract class AbstractAvroSerializer extends AbstractAvroSerDe {
    static final Logger logger = LoggerFactory.getLogger(AbstractAvroSerializer.class);

    private final EncoderFactory encoderFactory = EncoderFactory.get();

    protected byte[] serializeImpl(Object object)  {
        Schema schema = null;
        // null needs to treated specially since the client most likely just wants to send
        // an individual null value instead of making the subject a null type. Also, null in
        // Kafka has a special meaning for deletion in a topic with the compact retention policy.
        // Therefore, we will bypass schema registration and return a null value in Kafka, instead
        // of an Avro encoded null.
        if (object == null) {
            return null;
        }
        String restClientErrorMsg = "";
        try {
            int id;
            schema = AvroSchemaUtils.getSchema(object);
            String subject = schema.getFullName();
            if (config.isAutoRegisterSchema()) {
                restClientErrorMsg = "Error registering Avro schema: ";
                id = schemaRegistry.register(subject, schema);
            } else {
                restClientErrorMsg = "Error retrieving Avro schema: ";
                id = schemaRegistry.getId(subject, schema);
            }
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            out.write(MAGIC_BYTE);
            out.write(ByteBuffer.allocate(idSize).putInt(id).array());
            if (object instanceof byte[]) {
                out.write((byte[]) object);
            } else {
                BinaryEncoder encoder = encoderFactory.directBinaryEncoder(out, null);
                DatumWriter