/*
* 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.mina.avro.codec.serialization;
import org.apache.avro.Schema;
import org.apache.avro.generic.GenericContainer;
import org.apache.avro.generic.GenericData;
import org.apache.avro.generic.GenericDatumReader;
import org.apache.avro.io.BinaryDecoder;
import org.apache.avro.io.DecoderFactory;
import org.apache.avro.reflect.ReflectDatumReader;
import org.apache.mina.codec.IoBuffer;
import org.apache.mina.codec.ProtocolDecoderException;
import org.apache.mina.codec.delimited.IoBufferDecoder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
/**
* Avro Message Decoder
*
* Uses ReflectDatumReader to read the data from the stream
*/
public class AvroMessageDecoder<T extends GenericContainer> extends IoBufferDecoder<T> {
// Logger
public static final Logger LOG = LoggerFactory.getLogger(AvroMessageDecoder.class);
// Avro Schema used for decoding
private Schema schema;
/**
* Default Constructor
* @param schema Avro Schema to be used for decoding the messages
*/
public AvroMessageDecoder(Schema schema) {
if(schema == null) {
LOG.error("Avro Schema cannot be null");
throw new IllegalArgumentException("Avro Schema cannot be null");
}
this.schema = schema;
}
@Override
public T decode(IoBuffer input) {
BinaryDecoder binaryDecoder = DecoderFactory.get().binaryDecoder(input.array(), null);
ReflectDatumReader<T> reader = new ReflectDatumReader<T>(schema);
T result = null;
try {
result = reader.read(null, binaryDecoder);
}catch (IOException ioEx) {
LOG.error("Error while decoding", ioEx);
throw new ProtocolDecoderException(ioEx.getMessage());
}
return result;
}
}