Protobuf整合netty多种消息类型处理方案

1-1 前言

	大致上和前一篇文档里写的类似。其关键点还是procto文件的中做的文章，大致上的思路是我们定
义一个消息类型在最外层，然后需要的消息类型包装在里面，让后定义一个枚举，枚举里面就是定义
各种消息类型的标识，通过这样一种方式，可以实现动态的多消息类型的传输。

1-2 proto文件

syntax = "proto2";

package com.zt.proto;

option optimize_for = SPEED;
option java_package = "com.zt.proto";
option java_outer_classname = "MessageInfo";

message MessageData {
  enum MessageType{
    DOG = 1;
    CAT = 2;
    PIG = 3;
  }
  optional MessageType messageType = 1 ;
  oneof MessageBody{
    Dog dog = 2;
    Cat cat = 3;
    Pig pig = 4;
  }
}

message Dog {
  optional string name = 1;
  optional int32 age = 2;
}

message Cat {
  optional string name = 1;
  optional int32 age = 2;
  optional int32 sex = 3;
}

message Pig {
  optional string name = 1;
  optional int32 age = 2;
}

执行的命令

protoc  --java_out=src\main\java src\protobuf\PersonInfo.proto

1-3 netty相关

1-3-1 TestServer

package com.zt.proto;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;

/**
 * @Description:
 * @Date: 2020/12/15 10:53
 * @author: zt
 */
public class TestServer {
    public static void main(String[] args) {
        NioEventLoopGroup bossGroup = new NioEventLoopGroup();
        NioEventLoopGroup workGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap serverBootstrap = new ServerBootstrap();
            serverBootstrap.group(bossGroup, workGroup).channel(NioServerSocketChannel.class)
                    .handler(new LoggingHandler(LogLevel.INFO))
                    .childHandler(new TestInitializer());

            ChannelFuture channelFuture = serverBootstrap.bind(8899).sync();
            channelFuture.channel().closeFuture().sync();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            bossGroup.shutdownGracefully();
            workGroup.shutdownGracefully();
        }
    }
}

1-3-2 TestInitializer

package com.zt.proto;

import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.protobuf.ProtobufDecoder;
import io.netty.handler.codec.protobuf.ProtobufEncoder;
import io.netty.handler.codec.protobuf.ProtobufVarint32FrameDecoder;
import io.netty.handler.codec.protobuf.ProtobufVarint32LengthFieldPrepender;

/**
 * @Description:
 * @Date: 2020/12/15 10:59
 * @author: zt
 */
public class TestInitializer extends ChannelInitializer<SocketChannel> {

    @Override
    protected void initChannel(SocketChannel ch) throws Exception {
        ChannelPipeline pipeline = ch.pipeline();
        pipeline.addLast(new ProtobufVarint32FrameDecoder());
        pipeline.addLast(new ProtobufDecoder(MessageInfo.MessageData.getDefaultInstance()));
        pipeline.addLast(new ProtobufVarint32LengthFieldPrepender());
        // 第一次没出现Bf shu'xua是ProtobufEncoder
        pipeline.addLast(new ProtobufEncoder());

        pipeline.addLast(new TestServerHandler());
    }
}

1-3-3 TestServerHandler

package com.zt.proto;

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;

/**
 * @Description:
 * @Date: 2020/12/15 14:27
 * @author: zt
 */
public class TestServerHandler extends SimpleChannelInboundHandler<MessageInfo.MessageData> {
    @Override
    protected void channelRead0(ChannelHandlerContext channelHandlerContext, MessageInfo.MessageData msg) {
        MessageInfo.MessageData.MessageType messageType = msg.getMessageType();
        if (messageType == MessageInfo.MessageData.MessageType.Dog) {
            MessageInfo.Dog data = msg.getDog();
            System.out.println(data.getAge());
            System.out.println(data.getName());
        } else if (messageType == MessageInfo.MessageData.MessageType.Cat) {
            MessageInfo.Cat data = msg.getCat();
            System.out.println(data.getAge());
            System.out.println(data.getName());
            System.out.println(data.getSex());
        } else {
            MessageInfo.Pig data = msg.getPig();
            System.out.println(data.getAge());
            System.out.println(data.getName());
        }
    }
}

1-3-4 TestClient

package com.zt.proto;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioSocketChannel;

/**
 * @Description:
 * @Date: 2020/12/15 14:28
 * @author: zt
 */
public class TestClient {
    public static void main(String[] args) {
        EventLoopGroup eventLoopGroup = new NioEventLoopGroup();
        try {
            Bootstrap bootstrap = new Bootstrap();
            bootstrap.group(eventLoopGroup).channel(NioSocketChannel.class)
                    .handler(new TestClientInitializer());

            ChannelFuture channelFuture = bootstrap.connect("localhost", 8899).sync();
            channelFuture.channel().closeFuture().sync();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            eventLoopGroup.shutdownGracefully();
        }
    }

}

1-3-5 TestClientInitializer

package com.zt.proto;

import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.protobuf.ProtobufDecoder;
import io.netty.handler.codec.protobuf.ProtobufEncoder;
import io.netty.handler.codec.protobuf.ProtobufVarint32FrameDecoder;
import io.netty.handler.codec.protobuf.ProtobufVarint32LengthFieldPrepender;

/**
 * @Description:
 * @Date: 2020/12/15 14:31
 * @author: zt
 */
public class TestClientInitializer extends ChannelInitializer<SocketChannel> {
    @Override
    protected void initChannel(SocketChannel ch) throws Exception {
        ChannelPipeline pipeline = ch.pipeline();
        pipeline.addLast(new ProtobufVarint32FrameDecoder());
        pipeline.addLast(new ProtobufDecoder(MyDataInfo.MessageData.getDefaultInstance()));
        pipeline.addLast(new ProtobufVarint32LengthFieldPrepender());
        pipeline.addLast(new ProtobufEncoder());
        pipeline.addLast(new TestClientHandler());
    }
}

1-3-6 TestClientHandler

package com.zt.proto;

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;

import java.util.Random;

/**
 * @Description:
 * @Date: 2020/12/15 14:37
 * @author: zt
 */
public class TestClientHandler extends SimpleChannelInboundHandler<MessageInfo.MessageData> {
    @Override
    protected void channelRead0(ChannelHandlerContext channelHandlerContext, MessageInfo.MessageData msg) throws Exception {

    }

    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        // 这里模拟随机发送数据
        int dataType = new Random().nextInt(3);
        MessageInfo.MessageData msg = null;
        switch (dataType) {
            case 0:
                msg = MessageInfo.MessageData.newBuilder()
                        .setMessageType(MessageInfo.MessageData.MessageType.Dog)
                        .setDog(MessageInfo.Dog.newBuilder()
                                .setAge(1)
                                .setName("一只狗")
                                .build())
                        .build();

                break;
            case 1:
                msg = MessageInfo.MessageData.newBuilder()
                        .setMessageType(MessageInfo.MessageData.MessageType.Cat)
                        .setCat(MessageInfo.Cat.newBuilder()
                                .setAge(1)
                                .setName("一只猫")
                                .setSex(11)
                                .build())
                        .build();
                break;
            case 2:
                msg = MessageInfo.MessageData.newBuilder()
                        .setMessageType(MessageInfo.MessageData.MessageType.Pig)
                        .setPig(MessageInfo.Pig.newBuilder()
                                .setAge(1)
                                .setName("一只猪")
                                .build())
                        .build();
                break;
            default:
                break;
        }
        ctx.channel().writeAndFlush(msg);
    }
}

1-3-7 maven依赖

 <dependencies>
        <dependency>
            <groupId>com.google.protobuf</groupId>
            <artifactId>protobuf-java</artifactId>
            <version>${protobufJavaVersion}</version>
        </dependency>
        <dependency>
            <groupId>com.google.protobuf</groupId>
            <artifactId>protobuf-java-util</artifactId>
            <version>${protobufJavaUtilVersion}</version>
        </dependency>
        <dependency>
            <groupId>io.netty</groupId>
            <artifactId>netty-all</artifactId>
            <version>${nettyAllVersion}</version>
        </dependency>
    </dependencies>

1-3-8 说明

TestClientHandler
再验证客户端连接上服务段后我的发送消息写在回调函数里面，即是下面这段代码，我们在使用随机数来模拟随机发数据

@Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        // 这里模拟随机发送数据
        int dataType = new Random().nextInt(3);
        MessageInfo.MessageData msg = null;
        switch (dataType) {
            case 0:
                msg = MessageInfo.MessageData.newBuilder()
                        .setMessageType(MessageInfo.MessageData.MessageType.Dog)
                        .setDog(MessageInfo.Dog.newBuilder()
                                .setAge(1)
                                .setName("一只狗")
                                .build())
                        .build();

                break;
            case 1:
                msg = MessageInfo.MessageData.newBuilder()
                        .setMessageType(MessageInfo.MessageData.MessageType.Cat)
                        .setCat(MessageInfo.Cat.newBuilder()
                                .setAge(1)
                                .setName("一只猫")
                                .setSex(11)
                                .build())
                        .build();
                break;
            case 2:
                msg = MessageInfo.MessageData.newBuilder()
                        .setMessageType(MessageInfo.MessageData.MessageType.Pig)
                        .setPig(MessageInfo.Pig.newBuilder()
                                .setAge(1)
                                .setName("一只猪")
                                .build())
                        .build();
                break;
            default:
                break;
        }
        ctx.channel().writeAndFlush(msg);
    }
}

TestServerHandler 服务段的hanlder
我们在可以看到接受数据，加上数据类型的判断逻辑，将对应的数据类型的数据打印出来。

  @Override
    protected void channelRead0(ChannelHandlerContext channelHandlerContext, MessageInfo.MessageData msg) {
        MessageInfo.MessageData.MessageType messageType = msg.getMessageType();
        if (messageType == MessageInfo.MessageData.MessageType.Dog) {
            MessageInfo.Dog data = msg.getDog();
            System.out.println(data.getAge());
            System.out.println(data.getName());
        } else if (messageType == MessageInfo.MessageData.MessageType.Cat) {
            MessageInfo.Cat data = msg.getCat();
            System.out.println(data.getAge());
            System.out.println(data.getName());
            System.out.println(data.getSex());
        } else {
            MessageInfo.Pig data = msg.getPig();
            System.out.println(data.getAge());
            System.out.println(data.getName());
        }
    }

1-4 日志

1-4-1 服务段日志

我们多次重启客户端，随机发送不同的数据类型，在日志新的异常是重启客户端打印出来的，不影响我们分析相关代码的逻辑。
下面的服务段的日志信息

十二月 17, 2020 11:22:08 上午 io.netty.handler.logging.LoggingHandler channelRegistered
信息: [id: 0x1e972a2b] REGISTERED
十二月 17, 2020 11:22:08 上午 io.netty.handler.logging.LoggingHandler bind
信息: [id: 0x1e972a2b] BIND: 0.0.0.0/0.0.0.0:8899
十二月 17, 2020 11:22:08 上午 io.netty.handler.logging.LoggingHandler channelActive
信息: [id: 0x1e972a2b, L:/0:0:0:0:0:0:0:0:8899] ACTIVE
十二月 17, 2020 11:22:11 上午 io.netty.handler.logging.LoggingHandler channelRead
信息: [id: 0x1e972a2b, L:/0:0:0:0:0:0:0:0:8899] READ: [id: 0xf4e3bb4d, L:/127.0.0.1:8899 - R:/127.0.0.1:62042]
十二月 17, 2020 11:22:11 上午 io.netty.handler.logging.LoggingHandler channelReadComplete
信息: [id: 0x1e972a2b, L:/0:0:0:0:0:0:0:0:8899] READ COMPLETE
1
一只猪
十二月 17, 2020 11:22:16 上午 io.netty.channel.DefaultChannelPipeline onUnhandledInboundException
警告: An exceptionCaught() event was fired, and it reached at the tail of the pipeline. It usually means the last handler in the pipeline did not handle the exception.
java.io.IOException: 远程主机强迫关闭了一个现有的连接。
	at sun.nio.ch.SocketDispatcher.read0(Native Method)
	at sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:43)
	at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:223)
	at sun.nio.ch.IOUtil.read(IOUtil.java:192)
	at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:380)
	at io.netty.buffer.PooledByteBuf.setBytes(PooledByteBuf.java:247)
	at io.netty.buffer.AbstractByteBuf.writeBytes(AbstractByteBuf.java:1147)
	at io.netty.channel.socket.nio.NioSocketChannel.doReadBytes(NioSocketChannel.java:347)
	at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:148)
	at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:700)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:635)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:552)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:514)
	at io.netty.util.concurrent.SingleThreadEventExecutor$6.run(SingleThreadEventExecutor.java:1044)
	at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.lang.Thread.run(Thread.java:748)

十二月 17, 2020 11:22:19 上午 io.netty.handler.logging.LoggingHandler channelRead
信息: [id: 0x1e972a2b, L:/0:0:0:0:0:0:0:0:8899] READ: [id: 0x4140980b, L:/127.0.0.1:8899 - R:/127.0.0.1:62087]
十二月 17, 2020 11:22:19 上午 io.netty.handler.logging.LoggingHandler channelReadComplete
信息: [id: 0x1e972a2b, L:/0:0:0:0:0:0:0:0:8899] READ COMPLETE
1
一只狗
十二月 17, 2020 11:22:24 上午 io.netty.channel.DefaultChannelPipeline onUnhandledInboundException
警告: An exceptionCaught() event was fired, and it reached at the tail of the pipeline. It usually means the last handler in the pipeline did not handle the exception.
java.io.IOException: 远程主机强迫关闭了一个现有的连接。
	at sun.nio.ch.SocketDispatcher.read0(Native Method)
	at sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:43)
	at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:223)
	at sun.nio.ch.IOUtil.read(IOUtil.java:192)
	at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:380)
	at io.netty.buffer.PooledByteBuf.setBytes(PooledByteBuf.java:247)
	at io.netty.buffer.AbstractByteBuf.writeBytes(AbstractByteBuf.java:1147)
	at io.netty.channel.socket.nio.NioSocketChannel.doReadBytes(NioSocketChannel.java:347)
	at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:148)
	at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:700)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:635)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:552)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:514)
	at io.netty.util.concurrent.SingleThreadEventExecutor$6.run(SingleThreadEventExecutor.java:1044)
	at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.lang.Thread.run(Thread.java:748)

十二月 17, 2020 11:22:27 上午 io.netty.handler.logging.LoggingHandler channelRead
信息: [id: 0x1e972a2b, L:/0:0:0:0:0:0:0:0:8899] READ: [id: 0x44900222, L:/127.0.0.1:8899 - R:/127.0.0.1:62132]
十二月 17, 2020 11:22:27 上午 io.netty.handler.logging.LoggingHandler channelReadComplete
信息: [id: 0x1e972a2b, L:/0:0:0:0:0:0:0:0:8899] READ COMPLETE
1
一只狗
十二月 17, 2020 11:23:09 上午 io.netty.channel.DefaultChannelPipeline onUnhandledInboundException
警告: An exceptionCaught() event was fired, and it reached at the tail of the pipeline. It usually means the last handler in the pipeline did not handle the exception.
java.io.IOException: 远程主机强迫关闭了一个现有的连接。
	at sun.nio.ch.SocketDispatcher.read0(Native Method)
	at sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:43)
	at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:223)
	at sun.nio.ch.IOUtil.read(IOUtil.java:192)
	at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:380)
	at io.netty.buffer.PooledByteBuf.setBytes(PooledByteBuf.java:247)
	at io.netty.buffer.AbstractByteBuf.writeBytes(AbstractByteBuf.java:1147)
	at io.netty.channel.socket.nio.NioSocketChannel.doReadBytes(NioSocketChannel.java:347)
	at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:148)
	at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:700)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:635)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:552)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:514)
	at io.netty.util.concurrent.SingleThreadEventExecutor$6.run(SingleThreadEventExecutor.java:1044)
	at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.lang.Thread.run(Thread.java:748)

十二月 17, 2020 11:23:14 上午 io.netty.handler.logging.LoggingHandler channelRead
信息: [id: 0x1e972a2b, L:/0:0:0:0:0:0:0:0:8899] READ: [id: 0x011ea4a4, L:/127.0.0.1:8899 - R:/127.0.0.1:62205]
十二月 17, 2020 11:23:14 上午 io.netty.handler.logging.LoggingHandler channelReadComplete
信息: [id: 0x1e972a2b, L:/0:0:0:0:0:0:0:0:8899] READ COMPLETE
1
一只猫
11

原文链接：https://blog.csdn.net/qq_42641261/article/details/111311804