io.confluent.kafkarest.AvroConsumerState.java Source code

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Here is the source code for io.confluent.kafkarest.AvroConsumerState.java

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/**
 * Copyright 2015 Confluent Inc.
 *
 * Licensed 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 io.confluent.kafkarest;

import com.fasterxml.jackson.databind.JsonNode;

import java.util.Properties;

import io.confluent.kafka.serializers.KafkaAvroDecoder;
import io.confluent.kafkarest.converters.AvroConverter;
import io.confluent.kafkarest.entities.AvroConsumerRecord;
import kafka.javaapi.consumer.ConsumerConnector;
import kafka.message.MessageAndMetadata;
import kafka.serializer.Decoder;
import kafka.utils.VerifiableProperties;

/**
 * Avro implementation of ConsumerState, which decodes into GenericRecords or primitive types.
 */
public class AvroConsumerState extends ConsumerState<Object, Object, JsonNode, JsonNode> {

    // Note that this could be a static variable and shared, but that causes tests to break in
    // subtle ways because it causes state to be shared across tests, but only for the consumer.
    private Decoder<Object> decoder = null;

    public AvroConsumerState(KafkaRestConfig config, ConsumerInstanceId instanceId, ConsumerConnector consumer) {
        super(config, instanceId, consumer);
        Properties props = new Properties();
        props.setProperty("schema.registry.url", config.getString(KafkaRestConfig.SCHEMA_REGISTRY_URL_CONFIG));
        decoder = new KafkaAvroDecoder(new VerifiableProperties(props));
    }

    @Override
    protected Decoder<Object> getKeyDecoder() {
        return decoder;
    }

    @Override
    protected Decoder<Object> getValueDecoder() {
        return decoder;
    }

    @Override
    public ConsumerRecordAndSize<JsonNode, JsonNode> createConsumerRecord(MessageAndMetadata<Object, Object> msg) {
        AvroConverter.JsonNodeAndSize keyNode = AvroConverter.toJson(msg.key());
        AvroConverter.JsonNodeAndSize valueNode = AvroConverter.toJson(msg.message());
        return new ConsumerRecordAndSize<>(
                new AvroConsumerRecord(msg.topic(), keyNode.json, valueNode.json, msg.partition(), msg.offset()),
                keyNode.size + valueNode.size);
    }
}