netty5心跳与业务消息分发实例
继续基于我们之前的例子（参见netty5自定义私有协议实例 ），这次我们加上连接校验和心跳机制：
只要校验通过，客户端发送心跳和业务消息是两个不同的事件发送的，彼此互不干扰。针对以上流程，我们需要增加4个handler：客户端请求handler、心跳handler ，服务端校验handler、心跳处理handler。当然，引导类也得添加上面对应的handler。上代码：
新增客户端首次连接handler：
package com.wlf.netty.nettyclient.handler; import com.wlf.netty.nettyapi.javabean.Header; import com.wlf.netty.nettyapi.javabean.NettyMessage; import io.netty.channel.ChannelHandlerAdapter; import io.netty.channel.ChannelHandlerContext; import lombok.extern.slf4j.Slf4j; @Slf4j public class ControlClientHandler extends ChannelHandlerAdapter { @Override public void channelActive(ChannelHandlerContext ctx) throws Exception { ctx.writeAndFlush(buildControlReq()); } /** * 在处理过程中引发异常时被调用 * * @param ctx * @param cause * @throws Exception */ @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { log.error("[Client] conrol request error: {}", cause.getMessage()); ctx.fireExceptionCaught(cause); } /** * 构造请求消息体 * * @return */ private NettyMessage buildControlReq() { NettyMessage nettyMessage = new NettyMessage(); Header header = new Header(); byte[] data = buildControlData(); header.setDelimiter(0xABEF0101); header.setLength(data.length); header.setType((byte) 0); header.setReserved((byte) 0); nettyMessage.setHeader(header); // 设置数据包 nettyMessage.setData(data); return nettyMessage; } /** * 构造控制请求消息体 * * @return */ private byte[] buildControlData() { byte[] result = new byte[2]; result[0] = (byte) 1; result[1] = (byte) 16; return result; } }
服务端校验handler：
package com.wlf.netty.nettyserver.handler; import com.wlf.netty.nettyapi.javabean.Header; import com.wlf.netty.nettyapi.javabean.NettyMessage; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; import io.netty.channel.ChannelHandlerAdapter; import io.netty.channel.ChannelHandlerContext; import lombok.extern.slf4j.Slf4j; import java.net.InetSocketAddress; import java.util.Map; import java.util.concurrent.ConcurrentHashMap; @Slf4j public class ControlServerHandler extends ChannelHandlerAdapter { // 白名单列表 private String[] whiteList = new String[]{"127.0.0.1"}; private Map<String, Boolean> nodeCheck = new ConcurrentHashMap<>(); @Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { NettyMessage nettyMessage = (NettyMessage) msg; // 如果是控制数据格式请求消息，说明是客户端首次请求，校验白名单，否则进入下一个处理流程 if (nettyMessage.getHeader() != null && nettyMessage.getHeader().getType() == (byte) 0) { String nodeIndex = ctx.channel().remoteAddress().toString(); NettyMessage controlResponse = null; if (nodeCheck.containsKey(nodeIndex)) { log.warn("request ip : {} has requested.", nodeIndex); controlResponse = buildResponse(false); } else { InetSocketAddress address = (InetSocketAddress) ctx.channel().remoteAddress(); String ip = address.getAddress().getHostAddress(); boolean isOK = false; for (String whiteIp : whiteList) { if (ip.equals(whiteIp)) { isOK = true; break; } } if (isOK) { nodeCheck.put(nodeIndex, true); // 白名单校验通过，校验是否支持PCM格式 byte[] data = nettyMessage.getData(); ByteBuf buf = Unpooled.buffer(2); buf.writeBytes(data); byte sample = buf.readByte(); if (sample != (byte) 1) { log.error("sample : {} is not 1", sample); controlResponse = buildResponse(false); } else { controlResponse = buildResponse(true); } } else { log.error("ip : {} is not in whiteList : {}.", ip, whiteList); controlResponse = buildResponse(false); } } log.info("[server] The control response is : {}, data : {}", controlResponse, controlResponse.getData()); ctx.writeAndFlush(controlResponse); } else { ctx.fireChannelRead(msg); } } /** * 在处理过程中引发异常时被调用 * * @param ctx * @param cause * @throws Exception */ @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { log.error("[server] control response error: {}", cause.getMessage()); // 删除缓存 nodeCheck.remove(ctx.channel().remoteAddress().toString()); ctx.fireExceptionCaught(cause); } /** * 构造响应消息体 * * @param isOk * @return */ private NettyMessage buildResponse(boolean isOk) { NettyMessage nettyMessage = new NettyMessage(); Header header = new Header(); byte[] data = buildData(isOk); header.setDelimiter(0xABEF0101); header.setLength(data.length); header.setType((byte) 0); header.setReserved((byte) 0); nettyMessage.setHeader(header); nettyMessage.setData(data); return nettyMessage; } /** * 构建控制数据格式响应消息体 * * @param isOk * @return */ private byte[] buildData(boolean isOk) { ByteBuf result = null; if (isOk) { result = Unpooled.buffer(8); // 生成sid result.writeInt(buildSid()); // 心跳发送间隔，5000毫秒秒 result.writeInt(5000); } else { result = Unpooled.buffer(1); result.writeByte((byte) -1); } return result.array(); } private int buildSid() { int max = 100, min = 1; long randomNum = System.currentTimeMillis(); return (int) (randomNum % (max - min) + min); } }
心跳客户端handler：
package com.wlf.netty.nettyclient.handler; import com.wlf.netty.nettyapi.javabean.Header; import com.wlf.netty.nettyapi.javabean.NettyMessage; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; import io.netty.channel.ChannelHandlerAdapter; import io.netty.channel.ChannelHandlerContext; import io.netty.util.concurrent.ScheduledFuture; import lombok.extern.slf4j.Slf4j; import java.util.concurrent.TimeUnit; @Slf4j public class HeartBeatClientHandler extends ChannelHandlerAdapter { private volatile int interval = 5000; private volatile ScheduledFuture<?> heartBeat; @Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { NettyMessage nettyMessage = (NettyMessage) msg; // 接收控制数据响应消息成功，发送心跳给服务端 if (nettyMessage.getHeader() != null && nettyMessage.getHeader().getType() == (byte) 0) { byte[] data = nettyMessage.getData(); ByteBuf buf = Unpooled.buffer(8); buf.writeBytes(data); int sid = buf.readInt(); interval = buf.readInt(); log.info("[client] control response is OK, header : {}. sid : {}, interval : {}", nettyMessage.getHeader(), sid, interval); // 每interval（默认5000）豪秒发送一次心跳请求到服务端 heartBeat = ctx.executor().scheduleAtFixedRate(new Runnable() { @Override public void run() { NettyMessage heartBeat = buildHeartBeat(sid); log.info("[client] Client send heart beat message to server : ----> {}", heartBeat); ctx.writeAndFlush(heartBeat); } }, 0, interval, TimeUnit.MILLISECONDS); // 消息继续向后传 ctx.fireChannelRead(msg); } else {
ctx.fireChannedRead(msg);
}
} @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { log.error("[Client] heart request error: {}", cause.getMessage()); if (heartBeat != null) { heartBeat.cancel(true); heartBeat = null; } ctx.fireExceptionCaught(cause); } /** * 构造心跳请求消息体 * * @return */ private NettyMessage buildHeartBeat(int sid) { NettyMessage message = new NettyMessage(); Header header = new Header(); byte[] data = buildData(sid); header.setDelimiter(0xABEF0101); header.setLength(data.length); header.setType((byte) 3); header.setReserved((byte) 0); message.setHeader(header); // 设置数据包 message.setData(data); return message; } /** * 构建心跳响应消息体 * * @param sid * @return */ private byte[] buildData(int sid) { ByteBuf result = Unpooled.buffer(4); result.writeInt(sid); return result.array(); } }
服务端心跳handler：
package com.wlf.netty.nettyserver.handler; import com.wlf.netty.nettyapi.constant.MessageType; import com.wlf.netty.nettyapi.javabean.NettyMessage; import io.netty.channel.ChannelHandlerAdapter; import io.netty.channel.ChannelHandlerContext; import lombok.extern.slf4j.Slf4j; @Slf4j public class HeartBeatServerHandler extends ChannelHandlerAdapter { @Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { NettyMessage nettyMessage = (NettyMessage) msg; // 接收到心跳请求，打印心跳消息，否则进入下一处理流程 if (nettyMessage.getHeader() != null && nettyMessage.getHeader().getType() == (byte) 3) { log.info("[server] Receive client heart beat message : ----> {}", nettyMessage); } else { ctx.fireChannelRead(msg); } } /** * 在处理过程中引发异常时被调用 * * @param ctx * @param cause * @throws Exception */ @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { log.error("[server] heart response error: {}", cause.getMessage()); ctx.fireExceptionCaught(cause); } }
客户端发送业务消息NettyClientHandler修改，发送触发从channelAcitve事件改为channelRead事件：
@Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { NettyMessage nettyMessage = (NettyMessage) msg; // 接收控制数据响应消息成功，每5秒发送pcm数据 if (nettyMessage.getHeader() != null && nettyMessage.getHeader().getType() == (byte) 0) { ctx.writeAndFlush(buildClientRequest()); } // @Override // public void channelActive(ChannelHandlerContext ctx) throws Exception { // ctx.writeAndFlush(buildClientRequest()); // }
客户端引导类NettyClient修改，新增handler：
public void connect(int port, String host) throws Exception { NioEventLoopGroup workGroup = new NioEventLoopGroup(); try { Bootstrap bootstrap = new Bootstrap(); bootstrap.group(workGroup).channel(NioSocketChannel.class).option(ChannelOption.TCP_NODELAY, true) .handler(new ChannelInitializer<SocketChannel>() { @Override public void initChannel(SocketChannel channel) throws Exception { channel.pipeline().addLast(new NettyMessageDecoder()); channel.pipeline().addLast(new NettyMessageEncoder()); channel.pipeline().addLast(new ControlClientHandler()); channel.pipeline().addLast(new HeartBeatClientHandler()); channel.pipeline().addLast(new NettyClientHandler()); } }); ChannelFuture future = bootstrap.connect(host, port).sync(); future.channel().closeFuture().sync(); } finally { workGroup.shutdownGracefully(); } }
服务端引导类修改：
public void bind(int port) throws Exception { try { ServerBootstrap serverBootstrap = new ServerBootstrap(); serverBootstrap.group(bossGroup, workGroup).channel(NioServerSocketChannel.class) .option(ChannelOption.SO_BACKLOG, 100) .handler(new LoggingHandler(LogLevel.INFO)) .childHandler(new ChannelInitializer<SocketChannel>() { @Override public void initChannel(SocketChannel channel) throws Exception { channel.pipeline().addLast(new NettyMessageDecoder()); channel.pipeline().addLast(new NettyMessageEncoder()); channel.pipeline().addLast(new ControlServerHandler()); channel.pipeline().addLast(new HeartBeatServerHandler()); channel.pipeline().addLast(new NettyServerHandler()); } }); // 绑定端口 ChannelFuture channelFuture = serverBootstrap.bind(port).sync(); channelFuture.channel().closeFuture().sync(); } finally { bossGroup.shutdownGracefully(); workGroup.shutdownGracefully(); } }
我们跑起来看看，先跑服务端再跑客户端：
服务端输出：
22:55:33.725 [nioEventLoopGroup-1-0] INFO com.wlf.netty.nettyserver.handler.ControlServerHandler - [server] The control response is : NettyMessage{header=Header{delimiter=-1410399999, length=8, type=0, reserved=0}, data=[B@65aac359}, data : [0, 0, 0, 18, 0, 0, 19, -120]
22:55:33.741 [nioEventLoopGroup-1-0] INFO com.wlf.netty.nettyserver.handler.NettyServerHandler - [server] server receive client message : NettyMessage{header=Header{delimiter=-1410399999, length=8, type=1, reserved=0}, data=[B@75f76fa3}
22:55:33.752 [nioEventLoopGroup-1-0] INFO com.wlf.netty.nettyserver.handler.NettyServerHandler - data length: 8
22:55:33.752 [nioEventLoopGroup-1-0] INFO com.wlf.netty.nettyserver.handler.NettyServerHandler - startTime: 1572105096532
22:55:38.747 [nioEventLoopGroup-1-0] INFO com.wlf.netty.nettyserver.handler.HeartBeatServerHandler - [server] Receive client heart beat message : ----> NettyMessage{header=Header{delimiter=-1410399999, length=4, type=3, reserved=0}, data=[B@77e50de}
22:55:43.746 [nioEventLoopGroup-1-0] INFO com.wlf.netty.nettyserver.handler.HeartBeatServerHandler - [server] Receive client heart beat message : ----> NettyMessage{header=Header{delimiter=-1410399999, length=4, type=3, reserved=0}, data=[B@75305725}
22:55:48.769 [nioEventLoopGroup-1-0] INFO com.wlf.netty.nettyserver.handler.HeartBeatServerHandler - [server] Receive client heart beat message : ----> NettyMessage{header=Header{delimiter=-1410399999, length=4, type=3, reserved=0}, data=[B@29515fc1}
22:55:53.754 [nioEventLoopGroup-1-0] INFO com.wlf.netty.nettyserver.handler.HeartBeatServerHandler - [server] Receive client heart beat message : ----> NettyMessage{header=Header{delimiter=-1410399999, length=4, type=3, reserved=0}, data=[B@1dfc1da8}
22:55:58.739 [nioEventLoopGroup-1-0] INFO com.wlf.netty.nettyserver.handler.HeartBeatServerHandler - [server] Receive client heart beat message : ----> NettyMessage{header=Header{delimiter=-1410399999, length=4, type=3, reserved=0}, data=[B@68f15669}
22:56:03.738 [nioEventLoopGroup-1-0] INFO com.wlf.netty.nettyserver.handler.HeartBeatServerHandler - [server] Receive client heart beat message : ----> NettyMessage{header=Header{delimiter=-1410399999, length=4, type=3, reserved=0}, data=[B@1f8fad2d}
22:56:08.742 [nioEventLoopGroup-1-0] INFO com.wlf.netty.nettyserver.handler.HeartBeatServerHandler - [server] Receive client heart beat message : ----> NettyMessage{header=Header{delimiter=-1410399999, length=4, type=3, reserved=0}, data=[B@3c83464a}
客户端输出：
22:55:33.725 [nioEventLoopGroup-1-0] INFO com.wlf.netty.nettyclient.handler.HeartBeatClientHandler - [client] control response is OK, header : Header{delimiter=-1410399999, length=8, type=0, reserved=0}. sid : 18, interval : 5000
22:55:33.725 [nioEventLoopGroup-1-0] INFO com.wlf.netty.nettyclient.handler.HeartBeatClientHandler - [client] Client send heart beat message to server : ----> NettyMessage{header=Header{delimiter=-1410399999, length=4, type=3, reserved=0}, data=[B@b1db7b2}
22:55:38.747 [nioEventLoopGroup-1-0] INFO com.wlf.netty.nettyclient.handler.HeartBeatClientHandler - [client] Client send heart beat message to server : ----> NettyMessage{header=Header{delimiter=-1410399999, length=4, type=3, reserved=0}, data=[B@4958706c}
22:55:43.746 [nioEventLoopGroup-1-0] INFO com.wlf.netty.nettyclient.handler.HeartBeatClientHandler - [client] Client send heart beat message to server : ----> NettyMessage{header=Header{delimiter=-1410399999, length=4, type=3, reserved=0}, data=[B@1fb0fa50}
22:55:48.769 [nioEventLoopGroup-1-0] INFO com.wlf.netty.nettyclient.handler.HeartBeatClientHandler - [client] Client send heart beat message to server : ----> NettyMessage{header=Header{delimiter=-1410399999, length=4, type=3, reserved=0}, data=[B@4aeea171}
22:55:53.754 [nioEventLoopGroup-1-0] INFO com.wlf.netty.nettyclient.handler.HeartBeatClientHandler - [client] Client send heart beat message to server : ----> NettyMessage{header=Header{delimiter=-1410399999, length=4, type=3, reserved=0}, data=[B@2c282fb9}
22:55:58.739 [nioEventLoopGroup-1-0] INFO com.wlf.netty.nettyclient.handler.HeartBeatClientHandler - [client] Client send heart beat message to server : ----> NettyMessage{header=Header{delimiter=-1410399999, length=4, type=3, reserved=0}, data=[B@2679e140}
22:56:03.738 [nioEventLoopGroup-1-0] INFO com.wlf.netty.nettyclient.handler.HeartBeatClientHandler - [client] Client send heart beat message to server : ----> NettyMessage{header=Header{delimiter=-1410399999, length=4, type=3, reserved=0}, data=[B@3e03eda5}
22:56:08.742 [nioEventLoopGroup-1-0] INFO com.wlf.netty.nettyclient.handler.HeartBeatClientHandler - [client] Client send heart beat message to server : ----> NettyMessage{header=Header{delimiter=-1410399999, length=4, type=3, reserved=0}, data=[B@1d9363d}
从输出可以看到心跳是正常的，业务消息也发送了，但有一点要注意，就是业务消息只有一条，而且在心跳之前发送给了客户端。如果业务消息也是阻塞性的，那么就会出现问题，详见netty5心跳与阻塞性业务消息分发实例。
