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.client.codec; import c5db.client.C5Constants; import c5db.client.generated.Call; import io.netty.buffer.ByteBuf; import io.netty.channel.ChannelHandlerContext; import io.netty.handler.codec.MessageToMessageEncoder; import io.netty.handler.codec.http.websocketx.BinaryWebSocketFrame; import io.netty.handler.codec.http.websocketx.ContinuationWebSocketFrame; import io.netty.handler.codec.http.websocketx.WebSocketClientHandshaker; import io.netty.handler.codec.http.websocketx.WebSocketFrame; import io.protostuff.LowCopyProtobufOutput; import java.util.List; public class WebsocketProtostuffEncoder extends MessageToMessageEncoder<Call> { private static final long MAX_SIZE = C5Constants.MAX_CONTENT_LENGTH_HTTP_AGG; private final WebSocketClientHandshaker handShaker; public WebsocketProtostuffEncoder(WebSocketClientHandshaker handShaker) { this.handShaker = handShaker; } @Override protected void encode(ChannelHandlerContext channelHandlerContext, Call call, List<Object> objects) throws Exception { final LowCopyProtobufOutput lcpo = new LowCopyProtobufOutput(); Call.getSchema().writeTo(lcpo, call); final long size = lcpo.buffer.size(); if (size < MAX_SIZE) { ByteBuf byteBuf = channelHandlerContext.alloc().buffer((int) size); lcpo.buffer.finish().stream().forEach(byteBuf::writeBytes); final BinaryWebSocketFrame frame = new BinaryWebSocketFrame(byteBuf); objects.add(frame); } else { long remaining = size; boolean first = true; ByteBuf byteBuf = channelHandlerContext.alloc().buffer((int) size); lcpo.buffer.finish().stream().forEach(byteBuf::writeBytes); while (remaining > 0) { WebSocketFrame frame; if (remaining > MAX_SIZE) { final ByteBuf slice = byteBuf.copy((int) (size - remaining), (int) MAX_SIZE); if (first) { frame = new BinaryWebSocketFrame(false, 0, slice); first = false; } else { frame = new ContinuationWebSocketFrame(false, 0, slice); } remaining -= MAX_SIZE; } else { frame = new ContinuationWebSocketFrame(true, 0, byteBuf.copy((int) (size - remaining), (int) remaining)); remaining = 0; } objects.add(frame); } } } public WebSocketClientHandshaker getHandShaker() { return handShaker; } }