ableegoldman commented on a change in pull request #6592: URL: https://github.com/apache/kafka/pull/6592#discussion_r631327191
########## File path: clients/src/main/java/org/apache/kafka/common/serialization/ListDeserializer.java ########## @@ -0,0 +1,197 @@ +/* + * 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.kafka.common.serialization; + +import org.apache.kafka.clients.CommonClientConfigs; +import org.apache.kafka.common.KafkaException; +import org.apache.kafka.common.config.ConfigException; +import org.apache.kafka.common.errors.SerializationException; +import org.apache.kafka.common.utils.Utils; + +import java.io.ByteArrayInputStream; +import java.io.DataInputStream; +import java.io.IOException; +import java.lang.reflect.Constructor; +import java.lang.reflect.InvocationTargetException; +import java.util.ArrayList; +import java.util.List; +import java.util.Map; + +import static org.apache.kafka.common.serialization.Serdes.ListSerde.SerializationStrategy; +import static org.apache.kafka.common.utils.Utils.mkEntry; +import static org.apache.kafka.common.utils.Utils.mkMap; + +public class ListDeserializer<Inner> implements Deserializer<List<Inner>> { + + private static final Map<Class<? extends Deserializer<?>>, Integer> FIXED_LENGTH_DESERIALIZERS = mkMap( + mkEntry(ShortDeserializer.class, Short.BYTES), + mkEntry(IntegerDeserializer.class, Integer.BYTES), + mkEntry(FloatDeserializer.class, Float.BYTES), + mkEntry(LongDeserializer.class, Long.BYTES), + mkEntry(DoubleDeserializer.class, Double.BYTES), + mkEntry(UUIDDeserializer.class, 36) + ); + + private Deserializer<Inner> inner; + private Class<?> listClass; + private Integer primitiveSize; + + public ListDeserializer() {} + + public <L extends List<Inner>> ListDeserializer(Class<L> listClass, Deserializer<Inner> inner) { + if (listClass == null || inner == null) { + throw new IllegalArgumentException("ListDeserializer requires both \"listClass\" and \"innerDeserializer\" parameters to be provided during initialization"); + } + this.listClass = listClass; + this.inner = inner; + this.primitiveSize = FIXED_LENGTH_DESERIALIZERS.get(inner.getClass()); + } + + public Deserializer<Inner> getInnerDeserializer() { + return inner; + } + + @Override + public void configure(Map<String, ?> configs, boolean isKey) { + if (listClass != null || inner != null) { + throw new ConfigException("List deserializer was already initialized using a non-default constructor"); + } + configureListClass(configs, isKey); + configureInnerSerde(configs, isKey); + } + + private void configureListClass(Map<String, ?> configs, boolean isKey) { + String listTypePropertyName = isKey ? CommonClientConfigs.DEFAULT_LIST_KEY_SERDE_TYPE_CLASS : CommonClientConfigs.DEFAULT_LIST_VALUE_SERDE_TYPE_CLASS; + final Object listClassOrName = configs.get(listTypePropertyName); + if (listClassOrName == null) { + throw new ConfigException("Not able to determine the list class because it was neither passed via the constructor nor set in the config."); + } + try { + if (listClassOrName instanceof String) { + listClass = Utils.loadClass((String) listClassOrName, Object.class); + } else if (listClassOrName instanceof Class) { + listClass = (Class<?>) listClassOrName; + } else { + throw new KafkaException("Could not determine the list class instance using \"" + listTypePropertyName + "\" property."); + } + } catch (final ClassNotFoundException e) { + throw new ConfigException(listTypePropertyName, listClassOrName, "Deserializer's list class \"" + listClassOrName + "\" could not be found."); + } + } + + @SuppressWarnings("unchecked") + private void configureInnerSerde(Map<String, ?> configs, boolean isKey) { + String innerSerdePropertyName = isKey ? CommonClientConfigs.DEFAULT_LIST_KEY_SERDE_INNER_CLASS : CommonClientConfigs.DEFAULT_LIST_VALUE_SERDE_INNER_CLASS; + final Object innerSerdeClassOrName = configs.get(innerSerdePropertyName); + if (innerSerdeClassOrName == null) { + throw new ConfigException("Not able to determine the inner serde class because it was neither passed via the constructor nor set in the config."); + } + try { + if (innerSerdeClassOrName instanceof String) { + inner = Utils.newInstance((String) innerSerdeClassOrName, Serde.class).deserializer(); + } else if (innerSerdeClassOrName instanceof Class) { + inner = (Deserializer<Inner>) ((Serde) Utils.newInstance((Class) innerSerdeClassOrName)).deserializer(); + } else { + throw new KafkaException("Could not determine the inner serde class instance using \"" + innerSerdePropertyName + "\" property."); + } + inner.configure(configs, isKey); + primitiveSize = FIXED_LENGTH_DESERIALIZERS.get(inner.getClass()); + } catch (final ClassNotFoundException e) { + throw new ConfigException(innerSerdePropertyName, innerSerdeClassOrName, "Deserializer's inner serde class \"" + innerSerdeClassOrName + "\" could not be found."); + } + } + Review comment: Well, it's not at the end of the file right? But if you'd prefer to keep it that's fine too, was just a "super nit" suggestion 🙂 -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
