Java tutorial
/* * Copyright (C) 2014~2017 dinstone<dinstone@163.com> * * 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 com.dinstone.jrpc.transport.netty4; import java.io.Serializable; import com.dinstone.jrpc.protocol.Message; import com.dinstone.jrpc.protocol.MessageCodec; import io.netty.buffer.ByteBuf; import io.netty.channel.ChannelHandlerContext; import io.netty.handler.codec.MessageToByteEncoder; public class TransportProtocolEncoder extends MessageToByteEncoder<Message<? extends Serializable>> { private int maxObjectSize = Integer.MAX_VALUE; public TransportProtocolEncoder() { } /** * the maxObjectSize to get * * @return the maxObjectSize * @see TransportProtocolEncoder#maxObjectSize */ public int getMaxObjectSize() { return maxObjectSize; } /** * the maxObjectSize to set * * @param maxObjectSize * @see TransportProtocolEncoder#maxObjectSize */ public void setMaxObjectSize(int maxObjectSize) { if (maxObjectSize <= 0) { throw new IllegalArgumentException("maxObjectSize: " + maxObjectSize); } this.maxObjectSize = maxObjectSize; } @Override protected void encode(ChannelHandlerContext ctx, Message<? extends Serializable> message, ByteBuf out) throws Exception { byte[] rpcBytes = MessageCodec.encodeMessage(message); writeFrame(out, rpcBytes); } private void writeFrame(ByteBuf out, byte[] rpcBytes) { int objectSize = rpcBytes.length; if (objectSize > maxObjectSize) { throw new IllegalArgumentException( "The encoded object is too big: " + objectSize + " (> " + maxObjectSize + ')'); } // FrameLen = PrefixLen + RpcObjectSize out.writeInt(objectSize); out.writeBytes(rpcBytes); } }