netty5心跳与业务消息分发实例
2024-08-26 13:12:21
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。
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