/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.flink.statefun.flink.io.kafka; import com.google.protobuf.Any; import com.google.protobuf.InvalidProtocolBufferException; import java.nio.charset.StandardCharsets; import org.apache.flink.statefun.flink.io.generated.KafkaProducerRecord; import org.apache.flink.statefun.sdk.kafka.KafkaEgressSerializer; import org.apache.kafka.clients.producer.ProducerRecord; /** * A {@link KafkaEgressSerializer} used solely by sinks provided by the {@link * GenericKafkaSinkProvider}. * * <p>This serializer expects Protobuf messages of type {@link KafkaProducerRecord}, and simply * transforms those into Kafka's {@link ProducerRecord}. */ public final class GenericKafkaEgressSerializer implements KafkaEgressSerializer<Any> { private static final long serialVersionUID = 1L; @Override public ProducerRecord<byte[], byte[]> serialize(Any any) { KafkaProducerRecord protobufProducerRecord = asKafkaProducerRecord(any); return toProducerRecord(protobufProducerRecord); } private static KafkaProducerRecord asKafkaProducerRecord(Any message) { if (!message.is(KafkaProducerRecord.class)) { throw new IllegalStateException( "The generic Kafka egress expects only messages of type " + KafkaProducerRecord.class.getName()); } try { return message.unpack(KafkaProducerRecord.class); } catch (InvalidProtocolBufferException e) { throw new RuntimeException( "Unable to unpack message as a " + KafkaProducerRecord.class.getName(), e); } } private static ProducerRecord<byte[], byte[]> toProducerRecord( KafkaProducerRecord protobufProducerRecord) { final String key = protobufProducerRecord.getKey(); final String topic = protobufProducerRecord.getTopic(); final byte[] valueBytes = protobufProducerRecord.getValueBytes().toByteArray(); if (key == null || key.isEmpty()) { return new ProducerRecord<>(topic, valueBytes); } else { return new ProducerRecord<>(topic, key.getBytes(StandardCharsets.UTF_8), valueBytes); } } }