| package org.apache.directmemory.serialization.protobuf; |
| |
| /* |
| * 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 static java.lang.String.format; |
| |
| import java.io.ByteArrayOutputStream; |
| import java.io.IOException; |
| import java.lang.reflect.Method; |
| |
| import org.apache.directmemory.serialization.Serializer; |
| |
| import com.google.protobuf.GeneratedMessage; |
| import com.google.protobuf.Message; |
| |
| public final class ProtobufSerializer |
| implements Serializer |
| { |
| |
| private static final String NEW_BUILDER_METHOD = "newBuilder"; |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public <T> byte[] serialize( T obj ) |
| throws IOException |
| { |
| checkProtobufMessage( obj.getClass() ); |
| |
| final ByteArrayOutputStream baos = new ByteArrayOutputStream(); |
| |
| try |
| { |
| ( (Message) obj ).writeTo( baos ); |
| } |
| finally |
| { |
| try |
| { |
| baos.close(); |
| } |
| catch ( Exception e ) |
| { |
| // close quietly |
| } |
| } |
| |
| return baos.toByteArray(); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public <T> T deserialize( byte[] source, Class<T> clazz ) |
| throws IOException, ClassNotFoundException, InstantiationException, IllegalAccessException |
| { |
| clazz = checkProtobufMessage( clazz ); |
| |
| try |
| { |
| Method newBuilder = clazz.getMethod( NEW_BUILDER_METHOD ); |
| |
| // fixme no idea ATM how to fix type inference here |
| GeneratedMessage.Builder builder = (GeneratedMessage.Builder) newBuilder.invoke( clazz ); |
| |
| @SuppressWarnings( "unchecked" ) // cast should be safe since it is driven by the type |
| T deserialized = (T) builder.mergeFrom( source ).build(); |
| |
| return deserialized; |
| } |
| catch ( Throwable t ) |
| { |
| throw new IOException( t ); |
| } |
| } |
| |
| private static <T> Class<T> checkProtobufMessage( Class<T> clazz ) |
| { |
| if ( !Message.class.isAssignableFrom( clazz ) ) |
| { |
| throw new IllegalArgumentException( format( "Class %s cannot be serialized via Google Protobuf, it is not a %s", |
| clazz.getName(), |
| Message.class.getName() ) ); |
| } |
| return clazz; |
| } |
| |
| } |