org.apache.hadoop.io.serializer.avro.AvroSerialization Maven / Gradle / Ivy
/**
* 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.hadoop.io.serializer.avro;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import org.apache.avro.Schema;
import org.apache.avro.io.BinaryDecoder;
import org.apache.avro.io.BinaryEncoder;
import org.apache.avro.io.DatumReader;
import org.apache.avro.io.DatumWriter;
import org.apache.avro.io.DecoderFactory;
import org.apache.avro.io.EncoderFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.io.serializer.Deserializer;
import org.apache.hadoop.io.serializer.Serialization;
import org.apache.hadoop.io.serializer.Serializer;
/**
* Base class for providing serialization to Avro types.
*/
@InterfaceAudience.Public
@InterfaceStability.Evolving
public abstract class AvroSerialization extends Configured
implements Serialization{
@InterfaceAudience.Private
public static final String AVRO_SCHEMA_KEY = "Avro-Schema";
@Override
@InterfaceAudience.Private
public Deserializer getDeserializer(Class c) {
return new AvroDeserializer(c);
}
@Override
@InterfaceAudience.Private
public Serializer getSerializer(Class c) {
return new AvroSerializer(c);
}
/**
* Return an Avro Schema instance for the given class.
*/
@InterfaceAudience.Private
public abstract Schema getSchema(T t);
/**
* Create and return Avro DatumWriter for the given class.
*/
@InterfaceAudience.Private
public abstract DatumWriter getWriter(Class clazz);
/**
* Create and return Avro DatumReader for the given class.
*/
@InterfaceAudience.Private
public abstract DatumReader getReader(Class clazz);
class AvroSerializer implements Serializer {
private DatumWriter writer;
private BinaryEncoder encoder;
private OutputStream outStream;
AvroSerializer(Class clazz) {
this.writer = getWriter(clazz);
}
@Override
public void close() throws IOException {
encoder.flush();
outStream.close();
}
@Override
public void open(OutputStream out) throws IOException {
outStream = out;
encoder = EncoderFactory.get().binaryEncoder(out, encoder);
}
@Override
public void serialize(T t) throws IOException {
writer.setSchema(getSchema(t));
writer.write(t, encoder);
}
}
class AvroDeserializer implements Deserializer {
private DatumReader reader;
private BinaryDecoder decoder;
private InputStream inStream;
AvroDeserializer(Class clazz) {
this.reader = getReader(clazz);
}
@Override
public void close() throws IOException {
inStream.close();
}
@Override
public T deserialize(T t) throws IOException {
return reader.read(t, decoder);
}
@Override
public void open(InputStream in) throws IOException {
inStream = in;
decoder = DecoderFactory.get().binaryDecoder(in, decoder);
}
}
}