GenericAvroIntegrationTest.java

/*
 * Copyright 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.examples.streams;

import io.confluent.examples.streams.kafka.EmbeddedSingleNodeKafkaCluster;
import io.confluent.kafka.serializers.AbstractKafkaAvroSerDeConfig;
import io.confluent.kafka.serializers.KafkaAvroDeserializer;
import io.confluent.kafka.serializers.KafkaAvroSerializer;
import io.confluent.kafka.streams.serdes.avro.GenericAvroSerde;
import org.apache.avro.Schema;
import org.apache.avro.generic.GenericData;
import org.apache.avro.generic.GenericRecord;
import org.apache.kafka.clients.consumer.ConsumerConfig;
import org.apache.kafka.clients.producer.ProducerConfig;
import org.apache.kafka.common.serialization.ByteArrayDeserializer;
import org.apache.kafka.common.serialization.ByteArraySerializer;
import org.apache.kafka.common.serialization.Serde;
import org.apache.kafka.common.serialization.Serdes;
import org.apache.kafka.streams.KafkaStreams;
import org.apache.kafka.streams.StreamsBuilder;
import org.apache.kafka.streams.StreamsConfig;
import org.apache.kafka.streams.kstream.KStream;
import org.apache.kafka.streams.kstream.Produced;
import org.junit.BeforeClass;
import org.junit.ClassRule;
import org.junit.Test;

import java.util.Collections;
import java.util.List;
import java.util.Properties;

import static org.junit.Assert.assertEquals;

/**
 * End-to-end integration test that demonstrates how to work on Generic Avro data.
 *
 * See {@link SpecificAvroIntegrationTest} for the equivalent Specific Avro integration test.
 */
public class GenericAvroIntegrationTest {

  @ClassRule
  public static final EmbeddedSingleNodeKafkaCluster CLUSTER = new EmbeddedSingleNodeKafkaCluster();

  private static final String inputTopic = "inputTopic";
  private static final String outputTopic = "outputTopic";

  @BeforeClass
  public static void startKafkaCluster() throws Exception {
    CLUSTER.createTopic(inputTopic);
    CLUSTER.createTopic(outputTopic);
  }

  @Test
  public void shouldRoundTripGenericAvroDataThroughKafka() throws Exception {
    final Schema schema = new Schema.Parser().parse(
        getClass().getResourceAsStream("/avro/io/confluent/examples/streams/wikifeed.avsc"));
    final GenericRecord record = new GenericData.Record(schema);
    record.put("user", "alice");
    record.put("is_new", true);
    record.put("content", "lorem ipsum");
    final List<GenericRecord> inputValues = Collections.singletonList(record);

    //
    // Step 1: Configure and start the processor topology.
    //
    final StreamsBuilder builder = new StreamsBuilder();

    final Properties streamsConfiguration = new Properties();
    streamsConfiguration.put(StreamsConfig.APPLICATION_ID_CONFIG, "generic-avro-integration-test");
    streamsConfiguration.put(StreamsConfig.BOOTSTRAP_SERVERS_CONFIG, CLUSTER.bootstrapServers());
    streamsConfiguration.put(StreamsConfig.DEFAULT_KEY_SERDE_CLASS_CONFIG, Serdes.ByteArray().getClass().getName());
    streamsConfiguration.put(StreamsConfig.DEFAULT_VALUE_SERDE_CLASS_CONFIG, GenericAvroSerde.class);
    streamsConfiguration.put(AbstractKafkaAvroSerDeConfig.SCHEMA_REGISTRY_URL_CONFIG, CLUSTER.schemaRegistryUrl());
    streamsConfiguration.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");

    // Write the input data as-is to the output topic.
    //
    // Normally, because a) we have already configured the correct default serdes for keys and
    // values and b) the types for keys and values are the same for both the input topic and the
    // output topic, we would only need to define:
    //
    //   builder.stream(inputTopic).to(outputTopic);
    //
    // However, in the code below we intentionally override the default serdes in `to()` to
    // demonstrate how you can construct and configure a generic Avro serde manually.
    final Serde<String> stringSerde = Serdes.String();
    final Serde<GenericRecord> genericAvroSerde = new GenericAvroSerde();
    // Note how we must manually call `configure()` on this serde to configure the schema registry
    // url.  This is different from the case of setting default serdes (see `streamsConfiguration`
    // above), which will be auto-configured based on the `StreamsConfiguration` instance.
    final boolean isKeySerde = false;
    genericAvroSerde.configure(
        Collections.singletonMap(AbstractKafkaAvroSerDeConfig.SCHEMA_REGISTRY_URL_CONFIG, CLUSTER.schemaRegistryUrl()),
        isKeySerde);
    final KStream<String, GenericRecord> stream = builder.stream(inputTopic);
    stream.to(outputTopic, Produced.with(stringSerde, genericAvroSerde));

    final KafkaStreams streams = new KafkaStreams(builder.build(), streamsConfiguration);
    streams.start();

    //
    // Step 2: Produce some input data to the input topic.
    //
    final Properties producerConfig = new Properties();
    producerConfig.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, CLUSTER.bootstrapServers());
    producerConfig.put(ProducerConfig.ACKS_CONFIG, "all");
    producerConfig.put(ProducerConfig.RETRIES_CONFIG, 0);
    producerConfig.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, ByteArraySerializer.class);
    producerConfig.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, KafkaAvroSerializer.class);
    producerConfig.put(AbstractKafkaAvroSerDeConfig.SCHEMA_REGISTRY_URL_CONFIG, CLUSTER.schemaRegistryUrl());
    IntegrationTestUtils.produceValuesSynchronously(inputTopic, inputValues, producerConfig);

    //
    // Step 3: Verify the application's output data.
    //
    final Properties consumerConfig = new Properties();
    consumerConfig.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, CLUSTER.bootstrapServers());
    consumerConfig.put(ConsumerConfig.GROUP_ID_CONFIG, "generic-avro-integration-test-standard-consumer");
    consumerConfig.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
    consumerConfig.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, ByteArrayDeserializer.class);
    consumerConfig.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, KafkaAvroDeserializer.class);
    consumerConfig.put(AbstractKafkaAvroSerDeConfig.SCHEMA_REGISTRY_URL_CONFIG, CLUSTER.schemaRegistryUrl());
    final List<GenericRecord> actualValues = IntegrationTestUtils.waitUntilMinValuesRecordsReceived(
        consumerConfig,
        outputTopic,
        inputValues.size()
    );
    streams.close();
    assertEquals(inputValues, actualValues);
  }

}