Java tutorial
package com.kixeye.kixmpp.p2p.serialization; /* * #%L * Zaqar * %% * Copyright (C) 2014 Charles Barry * %% * Licensed 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. * #L% */ import com.dyuproject.protostuff.LinkedBuffer; import com.dyuproject.protostuff.ProtostuffIOUtil; import com.dyuproject.protostuff.Schema; import com.dyuproject.protostuff.runtime.RuntimeSchema; import com.kixeye.kixmpp.p2p.message.MessageRegistry; import io.netty.buffer.ByteBuf; import io.netty.buffer.ByteBufOutputStream; import io.netty.channel.ChannelHandlerContext; import io.netty.handler.codec.MessageToMessageEncoder; import java.io.IOException; import java.util.List; public class ProtostuffEncoder extends MessageToMessageEncoder<Object> { private final MessageRegistry registry; public ProtostuffEncoder(MessageRegistry registry) { this.registry = registry; } @Override protected void encode(ChannelHandlerContext ctx, Object msg, List<Object> out) throws Exception { if (msg instanceof ByteBuf) { // already serialized so just pass through ByteBuf buf = (ByteBuf) msg; out.add(buf.retain()); } else { // serialize ByteBuf buf = ctx.alloc().buffer(); serializeToByteBuf(registry, buf, msg); out.add(buf); } } /** * Expose serializer for sharing serialization and unit testing. * * @param registry * @param buf * @return * @throws IOException */ @SuppressWarnings({ "rawtypes", "unchecked" }) public static ByteBuf serializeToByteBuf(MessageRegistry registry, ByteBuf buf, Object msg) throws IOException { // write class id int classIdx = registry.getIdFromClass(msg.getClass()); buf.writeInt(classIdx); // write serialized object Schema schema = RuntimeSchema.getSchema(msg.getClass()); LinkedBuffer linkedBuffer = LinkedBuffer.allocate(1024); ProtostuffIOUtil.writeTo(new ByteBufOutputStream(buf), msg, schema, linkedBuffer); return buf; } }