Github user tillrohrmann commented on a diff in the pull request:
https://github.com/apache/flink/pull/6083#discussion_r195466309
--- Diff:
flink-end-to-end-tests/flink-confluent-schema-registry/src/main/java/AvroDeserializationConfluentSchema.java
---
@@ -0,0 +1,85 @@
+/*
+ * 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.
+ */
+
+import org.apache.flink.api.common.serialization.DeserializationSchema;
+import org.apache.flink.api.common.typeinfo.TypeInformation;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import io.confluent.kafka.schemaregistry.client.CachedSchemaRegistryClient;
+import io.confluent.kafka.schemaregistry.client.SchemaRegistryClient;
+import io.confluent.kafka.serializers.AbstractKafkaAvroSerDeConfig;
+import io.confluent.kafka.serializers.KafkaAvroDecoder;
+import org.apache.avro.generic.GenericData;
+import tech.allegro.schema.json2avro.converter.JsonAvroConverter;
+
+import java.io.IOException;
+
+/**
+ * The deserialization schema for the Avro type.
+ */
+public class AvroDeserializationConfluentSchema<T> implements
DeserializationSchema<T> {
+
+ private static final long serialVersionUID = 1L;
+
+ private Class<T> avroType;
+ private final String schemaRegistryUrl;
+ private final int identityMapCapacity;
+ private KafkaAvroDecoder kafkaAvroDecoder;
+
+ private ObjectMapper mapper;
+
+ private JsonAvroConverter jsonAvroConverter;
+
+ public AvroDeserializationConfluentSchema(Class<T> avroType, String
schemaRegistyUrl) {
+ this(avroType, schemaRegistyUrl,
AbstractKafkaAvroSerDeConfig.MAX_SCHEMAS_PER_SUBJECT_DEFAULT);
+ }
+
+ public AvroDeserializationConfluentSchema(Class<T> avroType, String
schemaRegistryUrl, int identityMapCapacity) {
+ this.avroType = avroType;
+ this.schemaRegistryUrl = schemaRegistryUrl;
+ this.identityMapCapacity = identityMapCapacity;
+ }
+
+ @Override
+ public T deserialize(byte[] message) throws IOException {
+ if (kafkaAvroDecoder == null) {
+ SchemaRegistryClient schemaRegistryClient = new
CachedSchemaRegistryClient(this.schemaRegistryUrl, this.identityMapCapacity);
+ this.kafkaAvroDecoder = new
KafkaAvroDecoder(schemaRegistryClient);
+ }
+ if (mapper == null) {
+ this.mapper = new ObjectMapper();
+ }
+
+ if (jsonAvroConverter == null) {
+ jsonAvroConverter = new JsonAvroConverter();
+ }
+ GenericData.Record record = (GenericData.Record)
this.kafkaAvroDecoder.fromBytes(message);
+ byte[] messageBytes = jsonAvroConverter.convertToJson(record);
+ return (T) this.mapper.readValue(messageBytes, avroType);
--- End diff --
Why do we have to introduce this indirection with Json? Converting an Avro
record into Json and then into the specific types seems quite cumbersome.
Better to directly read the record from the `message`.
---
