Java tutorial
/* * Copyright 2013-2018 Lilinfeng. * * 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. */ package fourteen.proprietaryprotocol.codec; import fourteen.proprietaryprotocol.struct.Header; import fourteen.proprietaryprotocol.struct.NettyMessage; import io.netty.buffer.ByteBuf; import io.netty.channel.ChannelHandlerContext; import io.netty.handler.codec.LengthFieldBasedFrameDecoder; import java.io.IOException; import java.util.HashMap; import java.util.Map; /** * @author Lilinfeng * @version 1.0 * @date 2014315 */ public class NettyMessageDecoder extends LengthFieldBasedFrameDecoder { MarshallingDecoder marshallingDecoder; public NettyMessageDecoder(int maxFrameLength, int lengthFieldOffset, int lengthFieldLength) throws IOException { super(maxFrameLength, lengthFieldOffset, lengthFieldLength); marshallingDecoder = new MarshallingDecoder(); } @Override protected Object decode(ChannelHandlerContext ctx, ByteBuf in) throws Exception { ByteBuf frame = (ByteBuf) super.decode(ctx, in); if (frame == null) { return null; } NettyMessage message = new NettyMessage(); Header header = new Header(); header.setCrcCode(frame.readInt()); header.setLength(frame.readInt()); header.setSessionId(frame.readLong()); header.setType(frame.readByte()); header.setPriority(frame.readByte()); int size = frame.readInt(); if (size > 0) { Map<String, Object> attch = new HashMap<String, Object>(size); int keySize = 0; byte[] keyArray = null; String key = null; for (int i = 0; i < size; i++) { keySize = frame.readInt(); keyArray = new byte[keySize]; frame.readBytes(keyArray); key = new String(keyArray, "UTF-8"); attch.put(key, marshallingDecoder.decode(frame)); } keyArray = null; key = null; header.setAttachment(attch); } if (frame.readableBytes() > 4) { message.setObject(marshallingDecoder.decode(frame)); } message.setHeader(header); return message; } }