Java tutorial
/* * Copyright 2014 WANdisco * * WANdisco 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 c5db.codec; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.socket.DatagramPacket; import io.netty.handler.codec.MessageToMessageEncoder; import io.protostuff.LinkBuffer; import io.protostuff.LowCopyProtobufOutput; import io.protostuff.LowCopyProtostuffOutput; import io.protostuff.Message; import io.protostuff.Schema; import java.net.InetSocketAddress; import java.nio.ByteBuffer; import java.util.List; /** * A specialized Protostuff decoder used to serialize Protostuff into a DatagramPackets and map them to an arbitrary * protostuff Message * * @param <T> The type of message to encode. */ public class UdpProtostuffEncoder<T extends Message<T>> extends MessageToMessageEncoder<UdpProtostuffEncoder.UdpProtostuffMessage<T>> { private final Schema<T> schema; private final boolean protostuffOutput; private final int bufferAllocSize; public UdpProtostuffEncoder(Schema<T> schema, boolean protostuffOutput) { this(schema, protostuffOutput, 512); } private UdpProtostuffEncoder(Schema<T> schema, boolean protostuffOutput, int bufferAllocSize) { this.schema = schema; this.protostuffOutput = protostuffOutput; this.bufferAllocSize = 512; } @Override protected void encode(ChannelHandlerContext ctx, UdpProtostuffMessage<T> msg, List<Object> out) throws Exception { LinkBuffer buffer = new LinkBuffer(bufferAllocSize); if (protostuffOutput) { LowCopyProtostuffOutput lcpo = new LowCopyProtostuffOutput(buffer); schema.writeTo(lcpo, msg.message); } else { LowCopyProtobufOutput lcpo = new LowCopyProtobufOutput(buffer); schema.writeTo(lcpo, msg.message); } List<ByteBuffer> buffers = buffer.finish(); ByteBuf data = Unpooled.wrappedBuffer(buffers.toArray(new ByteBuffer[buffers.size()])); data.retain(); DatagramPacket dg = new DatagramPacket(data, msg.remoteAddress); dg.retain(); out.add(dg); } public static class UdpProtostuffMessage<Q extends Message<Q>> { public final InetSocketAddress remoteAddress; public final Q message; public UdpProtostuffMessage(InetSocketAddress remoteAddress, Q message) { this.remoteAddress = remoteAddress; this.message = message; } } }