Netty实现简单私有协议

本文参考《Netty权威指南》

私有协议实现的功能：

1、基于Netty的NIO通信框架，提供高性能异步通信能力

2、提供消息的编码解码框架，实现POJO的序列化和反序列化

3、提供基于IP地址的白名单接入认证机制

4、链路有效性校验机制

5、断路重连机制

协议模型：

消息定义：

NettyMessage

名称	类型	长度	描述
header	Header	变长	消息头定义
body	Object	变长	请求消息：参数 响应消息：返回值

Header

名称	类型	长度	描述
crcCode	int	32	Netty消息校验码（三部分） 1、0xABEF:固定值，表明消息是Netty协议消息，2字节 2、主版本号：1~255,1字节 3、次版本号：1~255,1字节 crcCode=0xABEF+主版本号+次版本号
length	int	32	消息长度，包括消息头，消息体
sessionID	long	64	集群节点全局唯一，由会话生成器生成
type	Byte	8	0:业务请求消息 1:业务响应消息 2:业务ONE-WAY消息（既是请求又是响应） 3:握手请求消息 4:握手应答消息 5:心跳请求消息 6:心跳应答消息
priority	Byte	8	消息优先级：0~255
attachment	Mep<String,Object>	变长	可选，用于扩展消息头

参考：http://blog.csdn.net/iter_zc/article/details/39317311

依赖：

├── jboss-marshalling-1.3.0.CR9.jar
├── jboss-marshalling-serial-1.3.0.CR9.jar
└── netty-all-5.0.0.Alpha2.jar

源码：

├── Header.java
├── HeartBeatReqHandler.java
├── HeartBeatRespHandler.java
├── LoginAuthReqHandler.java
├── LoginAuthRespHandler.java
├── MarshallingCodeCFactory.java
├── MessageType.java
├── NettyClient.java
├── NettyConstants.java
├── NettyMarshallingDecoder.java
├── NettyMarshallingEncoder.java
├── NettyMessageDecoder.java
├── NettyMessageEncoder.java
├── NettyMessage.java
└── NettyServer.java

package com.xh.netty.test14;

import java.util.HashMap;
import java.util.Map;

/**
 * 消息头
 * Created by root on 1/11/18.
 */
public final class Header {
    private int crcCode = 0xabef0101;
    private int length;
    private long sessionID;
    private byte type;//消息类型
    private byte priority;//消息优先级
    private Map<String, Object> attachment = new HashMap<String, Object>();//附件


...//set get


    @Override
    public String toString() {
...
    }
}

package com.xh.netty.test14;

/**
 * 消息
 * Created by root on 1/11/18.
 */
public final class NettyMessage {

    private Header header;
    private Object body;

...//set get


    @Override
    public String toString() {
...
    }
}

package com.xh.netty.test14;

/**
 * 消息类型
 * Created by root on 1/12/18.
 */
public enum MessageType {

    //心跳请求，应答
    HEARTBEAT_REQ((byte) 5),
    HEARTBEAT_RESP((byte) 6),

    //握手请求，应答
    LOGIN_REQ((byte) 3),
    LOGIN_RESP((byte) 4);

    byte value;

    MessageType(byte value) {
        this.value = value;
    }
}

package com.xh.netty.test14;

/**
 * 常量
 * Created by root on 1/12/18.
 */
public class NettyConstants {
    public static int LOCAL_PORT = 8080;
    public static String LOCAL_IP = "127.0.0.1";

    public static int REMOTE_PORT = 80;
    public static String REMOTE_IP = "127.0.0.1";
}

package com.xh.netty.test14;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToMessageEncoder;

import java.util.List;
import java.util.Map;

/**
 * 消息编码器
 * Created by root on 1/11/18.
 */
public final class NettyMessageEncoder extends MessageToMessageEncoder<NettyMessage> {

    NettyMarshallingEncoder marshallingEncoder;

    /**
     * 这里和书中不一样，可能有问题
     */
    public NettyMessageEncoder() {
        //this.marshallingEncoder = new MarshallingEncoder(new DefaultMarshallerProvider(new SerialMarshallerFactory(), new MarshallingConfiguration()));
        this.marshallingEncoder = MarshallingCodeCFactory.buildMarshallingEncoder();

    }


    protected void encode(ChannelHandlerContext ctx, NettyMessage nettyMessage, List<Object> list) throws Exception {
        if (nettyMessage == null || nettyMessage.getHeader() == null) {
            throw new Exception("the encode message is null");
        }

        ByteBuf sendBuf = Unpooled.buffer();
        sendBuf.writeInt(nettyMessage.getHeader().getCrcCode());
        sendBuf.writeInt(nettyMessage.getHeader().getLength());
        sendBuf.writeLong(nettyMessage.getHeader().getSessionID());
        sendBuf.writeByte(nettyMessage.getHeader().getType());
        sendBuf.writeByte(nettyMessage.getHeader().getPriority());
        sendBuf.writeInt(nettyMessage.getHeader().getAttachment().size());

        String key = null;
        byte[] keyArray = null;
        Object value = null;
        for (Map.Entry<String, Object> param : nettyMessage.getHeader().getAttachment().entrySet()) {
            key = param.getKey();
            keyArray = key.getBytes("UTF-8");
            sendBuf.writeInt(keyArray.length);
            sendBuf.writeBytes(keyArray);
            value = param.getValue();
            marshallingEncoder.encode(ctx, value, sendBuf);

        }

        key = null;
        keyArray = null;
        value = null;
        if (nettyMessage.getBody() != null) {
            marshallingEncoder.encode(ctx, nettyMessage.getBody(), sendBuf);
        } else {
            sendBuf.writeInt(0);
        }
        // 在第4个字节出写入Buffer的长度
        int readableBytes = sendBuf.readableBytes();
        sendBuf.setInt(4, readableBytes);
        // 把Message添加到List传递到下一个Handler
        list.add(sendBuf);

    }

}

package com.xh.netty.test14;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.marshalling.MarshallerProvider;
import io.netty.handler.codec.marshalling.MarshallingEncoder;

/**
 * Created by root on 1/11/18.
 */
public class NettyMarshallingEncoder extends MarshallingEncoder {
    public NettyMarshallingEncoder(MarshallerProvider provider) {
        super(provider);
    }

    public void encode(ChannelHandlerContext ctx, Object msg, ByteBuf out) throws Exception {
        super.encode(ctx, msg, out);
    }
}

package com.xh.netty.test14;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.LengthFieldBasedFrameDecoder;

import java.util.HashMap;
import java.util.Map;

/**
 * 消息解码器
 * Created by root on 1/11/18.
 */
public class NettyMessageDecoder extends LengthFieldBasedFrameDecoder {
    private NettyMarshallingDecoder marshallingDecoder;


    public NettyMessageDecoder(int maxFrameLength, int lengthFieldOffset,
                               int lengthFieldLength,int lengthAdjustment, int initialBytesToStrip) {
        super(maxFrameLength, lengthFieldOffset, lengthFieldLength, lengthAdjustment, initialBytesToStrip);
        marshallingDecoder = MarshallingCodeCFactory.buildMarshallingDecoder();
    }
    @Override
    protected Object decode(ChannelHandlerContext ctx, ByteBuf in) throws Exception {
        ByteBuf frame = (ByteBuf) super.decode(ctx, in);
        if (frame == null) {
            System.out.println("NettyMessageDecoder NULL");
            return null;
        }

        //???
        NettyMessage message = new NettyMessage();
        Header header = new Header();
        header.setCrcCode(frame.readInt());
        header.setLength(frame.readInt());
        header.setSessionID(frame.readLong());
        header.setType(frame.readByte());
        header.setPriority(frame.readByte());
        int size = frame.readInt();
        if (size > 0) {
            Map attch = new HashMap<String, Object>(size);
            int keySize = 0;
            byte[] keyArray = null;
            String key = null;
            for (int i = 0; i < size; i++) {
                keySize = frame.readInt();
                keyArray = new byte[keySize];
                in.readBytes(keyArray);
                key = new String(keyArray, "UTF-8");
                attch.put(key, marshallingDecoder.decode(ctx, frame));
            }
            key = null;
            keyArray = null;
            header.setAttachment(attch);
        }

        if (frame.readableBytes() > 0) {
            message.setBody(marshallingDecoder.decode(ctx, frame));
        }

        message.setHeader(header);
        return message;
    }
}

package com.xh.netty.test14;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.marshalling.MarshallingDecoder;
import io.netty.handler.codec.marshalling.UnmarshallerProvider;

/**
 * Created by root on 1/11/18.
 */
public class NettyMarshallingDecoder extends MarshallingDecoder {

    public NettyMarshallingDecoder(UnmarshallerProvider provider) {
        super(provider);
    }

    public NettyMarshallingDecoder(UnmarshallerProvider provider, int maxObjectSize){
        super(provider, maxObjectSize);
    }

    public Object decode(ChannelHandlerContext ctx, ByteBuf in) throws Exception {
        return super.decode(ctx, in);
    }

}

package com.xh.netty.test14;

import io.netty.handler.codec.marshalling.DefaultMarshallerProvider;
import io.netty.handler.codec.marshalling.DefaultUnmarshallerProvider;
import io.netty.handler.codec.marshalling.MarshallerProvider;
import io.netty.handler.codec.marshalling.UnmarshallerProvider;
import org.jboss.marshalling.MarshallerFactory;
import org.jboss.marshalling.Marshalling;
import org.jboss.marshalling.MarshallingConfiguration;

/**
 * Created by root on 1/11/18.
 */
public class MarshallingCodeCFactory {

    public static NettyMarshallingDecoder buildMarshallingDecoder() {
        MarshallerFactory marshallerFactory = Marshalling.getProvidedMarshallerFactory("serial");
        MarshallingConfiguration configuration = new MarshallingConfiguration();
        configuration.setVersion(5);
        UnmarshallerProvider provider = new DefaultUnmarshallerProvider(marshallerFactory, configuration);
        NettyMarshallingDecoder decoder = new NettyMarshallingDecoder(provider, 1024);
        return decoder;
    }

    public static NettyMarshallingEncoder buildMarshallingEncoder() {
        MarshallerFactory marshallerFactory = Marshalling.getProvidedMarshallerFactory("serial");
        MarshallingConfiguration configuration = new MarshallingConfiguration();
        configuration.setVersion(5);
        MarshallerProvider provider = new DefaultMarshallerProvider(marshallerFactory, configuration);
        NettyMarshallingEncoder encoder = new NettyMarshallingEncoder(provider);
        return encoder;
    }
}

package com.xh.netty.test14;

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

/**
 * 握手认证(client)
 * Created by root on 1/12/18.
 */
public class LoginAuthReqHandler extends ChannelHandlerAdapter {

    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        //握手请求
        ctx.writeAndFlush(buildLoginReq());
        System.out.println("client: send LoginAuthReq ---> " + buildLoginReq());
    }

    private NettyMessage buildLoginReq() {
        NettyMessage message = new NettyMessage();
        Header header = new Header();
        header.setType((byte) 3);
        message.setHeader(header);
        message.setBody((byte) 0);
        return message;
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        //握手应答消息
        NettyMessage message = (NettyMessage) msg;
        if (message.getHeader() != null && message.getHeader().getType() == MessageType.LOGIN_RESP.value) {
            byte loginResult = (Byte) message.getBody();
            if (loginResult != (byte) 0) {
                //如果应答消息体不为0则认证失败
                ctx.close();
            } else {
                System.out.println("client:Login is OK --->" + message);
                ctx.fireChannelRead(message);
            }

        } else {
            //通知下一个Handler
            ctx.fireChannelRead(message);
        }


    }

    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
        ctx.flush();
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        ctx.close();
    }
}

package com.xh.netty.test14;

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

import java.net.InetSocketAddress;
import java.util.HashMap;
import java.util.Map;

/**
 * 握手认证(server)
 * Created by root on 1/12/18.
 */
public class LoginAuthRespHandler extends ChannelHandlerAdapter {
    //已登录列表
    Map node = new HashMap<String, Boolean>();
    //白名单
    private String[] whiteList = {"127.0.0.1"};

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        NettyMessage message = (NettyMessage) msg;

        //握手请求消息
        if (message != null && message.getHeader().getType() == MessageType.LOGIN_REQ.value) {
            String nodeInde = ctx.channel().remoteAddress().toString();
            System.out.println("server:receive  LoginAuthReq <--- " + message);
            NettyMessage loginResp = null;
            //拒绝重复登录
            if (node.containsKey(nodeInde)) {
                loginResp = buildResp((byte) -1);
            } else {
                InetSocketAddress address = (InetSocketAddress) ctx.channel().remoteAddress();
                Boolean isOK = false;
                String IP = address.getAddress().getHostAddress();
                for (String WIP : whiteList) {
                    if (WIP.equalsIgnoreCase(IP)) {
                        isOK = true;
                        break;
                    }
                }
                loginResp = isOK ? buildResp((byte) 0) : buildResp((byte) -1);
                if (isOK) {
                    node.put(nodeInde, true);
                }

            }
            System.out.println("server:send LoginAuthResp ---> " + loginResp);
            ctx.writeAndFlush(loginResp);
        } else {
            ctx.fireChannelRead(message);
        }
    }

    private NettyMessage buildResp(byte b) {
        NettyMessage message = new NettyMessage();
        Header header = new Header();
        header.setType(MessageType.LOGIN_RESP.value);
        message.setHeader(header);
        message.setBody(b);
        return message;
    }

    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
        ctx.flush();
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        //删除缓存
        node.remove(ctx.channel().remoteAddress().toString());
        ctx.close();
        ctx.fireExceptionCaught(cause);
    }
}

package com.xh.netty.test14;

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

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

/**
 * 心跳检测（client）
 * Created by root on 1/12/18.
 */
public class HeartBeatReqHandler extends ChannelHandlerAdapter {

    private volatile ScheduledFuture<?> heartBeat;

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        NettyMessage message = (NettyMessage) msg;
        //握手成功，主动发送心跳
        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 HEARTBEAT_RESP ---> " + message);
        } else {
            ctx.fireChannelRead(message);
        }
    }

    private class HeartBeatTask implements Runnable {
        private ChannelHandlerContext ctx;

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

        public void run() {
            NettyMessage message = buildHeartBeat();
            System.out.println("client: send HeartBeat to server --->" + message);
            ctx.writeAndFlush(message);
        }

        private NettyMessage buildHeartBeat() {
            NettyMessage message = new NettyMessage();
            Header header = new Header();
            header.setType(MessageType.HEARTBEAT_REQ.value);
            message.setHeader(header);
            message.setBody((byte) 0);
            return message;
        }
    }

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

package com.xh.netty.test14;

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

/**
 * 心跳检测（server）
 * Created by root on 1/12/18.
 */
public class HeartBeatRespHandler extends ChannelHandlerAdapter {

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        NettyMessage message = (NettyMessage) msg;
        if (message.getHeader() != null && message.getHeader().getType() == MessageType.HEARTBEAT_REQ.value) {
            System.out.println("server:receive client HeartBeat ---> " + message);
            NettyMessage heartBeat = buildHeartBeat();
            ctx.writeAndFlush(heartBeat);
            System.out.println("server:send  HeartBeat to client ---> " + heartBeat);
        } else {
            ctx.fireChannelRead(msg);
        }
    }

    private NettyMessage buildHeartBeat() {
        NettyMessage message = new NettyMessage();
        Header header = new Header();
        header.setType(MessageType.HEARTBEAT_RESP.value);
        message.setHeader(header);
        message.setBody((byte) 0);
        return message;
    }
}

package com.xh.netty.test14;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.timeout.ReadTimeoutHandler;

import java.net.InetSocketAddress;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

/**
 * 客户端
 * Created by root on 1/11/18.
 */
public class NettyClient {
    ScheduledExecutorService executorService = Executors.newScheduledThreadPool(1);
    EventLoopGroup group = new NioEventLoopGroup();

    public void connect(int port, String host) {

        //client NIO thread
        try {
            Bootstrap b = new Bootstrap();
            b.group(group).channel(NioSocketChannel.class)
                    .option(ChannelOption.TCP_NODELAY, true)
                    .handler(new ChannelInitializer<SocketChannel>() {
                        protected void initChannel(SocketChannel ch) throws Exception {
                            ch.pipeline().addLast(new NettyMessageDecoder(1024 * 1024, 4, 4, -8, 0));
                            ch.pipeline().addLast(new NettyMessageEncoder());
                            ch.pipeline().addLast(new ReadTimeoutHandler(50));
                            ch.pipeline().addLast(new LoginAuthReqHandler());
                            ch.pipeline().addLast(new HeartBeatReqHandler());

                        }
                    });

            //异步连接
            ChannelFuture future = b.connect(
                    new InetSocketAddress(host, port)
                    //指定本地的端口
                    //new InetSocketAddress(NettyConstants.LOCAL_IP, NettyConstants.LOCAL_PORT)
            ).sync();
            System.out.println("client: connect to server host:" + host + ", port:" + port);
            future.channel().closeFuture().sync();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            //释放资源，重连
            executorService.execute(new Runnable() {
                public void run() {
                    try {
                        TimeUnit.SECONDS.sleep(5);
                        //重连
                        connect(NettyConstants.REMOTE_PORT, NettyConstants.REMOTE_IP);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            });
        }

    }


    public static void main(String[] args) {
        new NettyClient().connect(NettyConstants.REMOTE_PORT, NettyConstants.REMOTE_IP);
    }
}

package com.xh.netty.test14;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;
import io.netty.handler.timeout.ReadTimeoutHandler;

/**
 * 服务端
 * Created by root on 1/11/18.
 */
public class NettyServer {
    public void bind(int port) throws InterruptedException {

        EventLoopGroup bossGrop = new NioEventLoopGroup();
        EventLoopGroup workerGrop = new NioEventLoopGroup();
        ServerBootstrap bootstrap = new ServerBootstrap();
        bootstrap.group(bossGrop, workerGrop).channel(NioServerSocketChannel.class)
                .option(ChannelOption.SO_BACKLOG, 1024)
                .handler(new LoggingHandler(LogLevel.INFO))
                .childHandler(new ChannelInitializer<SocketChannel>() {
                    protected void initChannel(SocketChannel ch) throws Exception {
                        ch.pipeline().addLast(new NettyMessageDecoder(1024 * 1024, 4, 4, -8, 0));
                        ch.pipeline().addLast(new NettyMessageEncoder());
                        ch.pipeline().addLast(new ReadTimeoutHandler(50));
                        ch.pipeline().addLast(new LoginAuthRespHandler());
                        ch.pipeline().addLast(new HeartBeatRespHandler());
                    }
                });
        ChannelFuture future = bootstrap.bind(port).sync();
        System.out.println("server: start ok ! host:" + NettyConstants.REMOTE_IP + ",port:" + NettyConstants.REMOTE_PORT);
        future.channel().closeFuture().sync();
    }

    public static void main(String[] args) throws InterruptedException {
        new NettyServer().bind(NettyConstants.REMOTE_PORT);
    }
}