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Apache Jena Fuseki server Kafka connector
/*
* 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 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;
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 org.slf4j.Logger;
import org.slf4j.LoggerFactory;
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.serialization.Serdes.ListSerde;
import org.apache.kafka.common.utils.Utils;
public class ListDeserializer implements Deserializer> {
final Logger log = LoggerFactory.getLogger(ListDeserializer.class);
private static final Map>, 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;
private Class> listClass;
private Integer primitiveSize;
public ListDeserializer() {}
public > ListDeserializer(Class listClass, Deserializer inner) {
if (listClass == null || inner == null) {
log.error("Could not construct ListDeserializer as not all required parameters were present -- listClass: {}, inner: {}", listClass, inner);
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 innerDeserializer() {
return inner;
}
@Override
public void configure(Map configs, boolean isKey) {
if (listClass != null || inner != null) {
log.error("Could not configure ListDeserializer as some parameters were already set -- listClass: {}, inner: {}", listClass, inner);
throw new ConfigException("List deserializer was already initialized using a non-default constructor");
}
configureListClass(configs, isKey);
configureInnerSerde(configs, isKey);
}
private void configureListClass(Map 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 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) ((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.");
}
}
@SuppressWarnings("unchecked")
private List createListInstance(int listSize) {
try {
Constructor> listConstructor;
try {
listConstructor = (Constructor>) listClass.getConstructor(Integer.TYPE);
return listConstructor.newInstance(listSize);
} catch (NoSuchMethodException e) {
listConstructor = (Constructor>) listClass.getConstructor();
return listConstructor.newInstance();
}
} catch (InstantiationException | IllegalAccessException | NoSuchMethodException |
IllegalArgumentException | InvocationTargetException e) {
log.error("Failed to construct list due to ", e);
throw new KafkaException("Could not construct a list instance of \"" + listClass.getCanonicalName() + "\"", e);
}
}
private SerializationStrategy parseSerializationStrategyFlag(final int serializationStrategyFlag) throws IOException {
if (serializationStrategyFlag < 0 || serializationStrategyFlag >= SerializationStrategy.VALUES.length) {
throw new SerializationException("Invalid serialization strategy flag value");
}
return SerializationStrategy.VALUES[serializationStrategyFlag];
}
private List deserializeNullIndexList(final DataInputStream dis) throws IOException {
int nullIndexListSize = dis.readInt();
List nullIndexList = new ArrayList<>(nullIndexListSize);
while (nullIndexListSize != 0) {
nullIndexList.add(dis.readInt());
nullIndexListSize--;
}
return nullIndexList;
}
@Override
public List deserialize(String topic, byte[] data) {
if (data == null) {
return null;
}
try (final DataInputStream dis = new DataInputStream(new ByteArrayInputStream(data))) {
SerializationStrategy serStrategy = parseSerializationStrategyFlag(dis.readByte());
List nullIndexList = null;
if (serStrategy == SerializationStrategy.CONSTANT_SIZE) {
// In CONSTANT_SIZE strategy, indexes of null entries are decoded from a null index list
nullIndexList = deserializeNullIndexList(dis);
}
final int size = dis.readInt();
List deserializedList = createListInstance(size);
for (int i = 0; i < size; i++) {
int entrySize = serStrategy == SerializationStrategy.CONSTANT_SIZE ? primitiveSize : dis.readInt();
if (entrySize == ListSerde.NULL_ENTRY_VALUE || (nullIndexList != null && nullIndexList.contains(i))) {
deserializedList.add(null);
continue;
}
byte[] payload = new byte[entrySize];
if (dis.read(payload) == -1) {
log.error("Ran out of bytes in serialized list");
log.trace("Deserialized list so far: {}", deserializedList); // avoid logging actual data above TRACE level since it may contain sensitive information
throw new SerializationException("End of the stream was reached prematurely");
}
deserializedList.add(inner.deserialize(topic, payload));
}
return deserializedList;
} catch (IOException e) {
throw new KafkaException("Unable to deserialize into a List", e);
}
}
@Override
public void close() {
if (inner != null) {
inner.close();
}
}
}