com.book.netty5.client.HeartBeatReqHandler.java Source code

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/*
 * 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 com.book.netty5.client;

import io.netty.channel.ChannelHandlerAdapter;
import io.netty.channel.ChannelHandlerContext;

import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;

import com.book.netty5.MessageType;
import com.book.netty5.struct.Header;
import com.book.netty5.struct.NettyMessage;

/**
 * @author Lilinfeng
 * @date 2014315
 * @version 1.0
 */
public class HeartBeatReqHandler extends ChannelHandlerAdapter {

    private volatile ScheduledFuture<?> heartBeat;

    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        NettyMessage message = (NettyMessage) msg;
        // ?????
        if (message.getHeader() != null && message.getHeader().getType() == MessageType.LOGIN_RESP.value()) {
            heartBeat = ctx.executor().scheduleAtFixedRate(new HeartBeatReqHandler.HeartBeatTask(ctx), 0, 5000,
                    TimeUnit.MILLISECONDS);
        } else if (message.getHeader() != null
                && message.getHeader().getType() == MessageType.HEARTBEAT_RESP.value()) {
            System.out.println("Client receive server heart beat message : ---> " + message);
        } else
            ctx.fireChannelRead(msg);
    }

    private class HeartBeatTask implements Runnable {

        private final ChannelHandlerContext ctx;

        public HeartBeatTask(final ChannelHandlerContext ctx) {
            this.ctx = ctx;
        }

        public void run() {
            NettyMessage heatBeat = buildHeatBeat();
            System.out.println("Client send heart beat messsage to server : ---> " + heatBeat);
            ctx.writeAndFlush(heatBeat);
        }

        private NettyMessage buildHeatBeat() {
            NettyMessage message = new NettyMessage();
            Header header = new Header();
            header.setType(MessageType.HEARTBEAT_REQ.value());
            message.setHeader(header);
            return message;
        }
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        cause.printStackTrace();
        if (heartBeat != null) {
            heartBeat.cancel(true);
            heartBeat = null;
        }
        ctx.fireExceptionCaught(cause);
    }
}