Netty 集成google ProtoBuf 开发私有协议之实战开发

- 日理万妓 2023-10-10 12:15 30阅读 0赞

本文基于[Netty 集成google ProtoBuf 开发私有协议][Netty _google ProtoBuf],进行实战功能开发

本文参考借鉴:[https://blog.csdn.net/kunfeisang5551/article/details/107957256][https_blog.csdn.net_kunfeisang5551_article_details_107957256]

## 第一步：新建自定义协议文本对象User.proto ##

syntax = "proto3";
    //生成的包名，此处根据实际来修改
    option java_package = "com.netty.protobuf";
    //类名
    option java_outer_classname="UserInfo";
    
    message UserMsg{
      int32 id=1;
      string name=2;
      int32 age=3;
      int32 state=4;
    }

## 第二步：Java 项目集成Google ProtoBuf 功能添加如下jar 包依赖 ##

<dependencies>
    	    
    		<dependency>
    			<groupId>io.netty</groupId>
    			<artifactId>netty-all</artifactId>
    			<version>4.1.42.Final</version>
    		</dependency>
    		
    		<dependency>
    			<groupId>com.google.protobuf</groupId>
    			<artifactId>protobuf-java</artifactId>
    			<version>3.11.0</version>
    		</dependency>
    	</dependencies>

## 第三步:新建Netty 服务端程序启动入口及其消息处理器(Handler) ##

服务端代码:EchoServer.java

package com.netty.server.two;
    
    import com.netty.protobuf.UserInfo;
    import com.netty.server.two.handler.EchoServerHandler;
    import io.netty.bootstrap.ServerBootstrap;
    import io.netty.channel.ChannelFuture;
    import io.netty.channel.ChannelInitializer;
    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.codec.protobuf.ProtobufDecoder;
    import io.netty.handler.codec.protobuf.ProtobufEncoder;
    import io.netty.handler.codec.protobuf.ProtobufVarint32FrameDecoder;
    import io.netty.handler.codec.protobuf.ProtobufVarint32LengthFieldPrepender;
    import io.netty.handler.logging.LogLevel;
    import io.netty.handler.logging.LoggingHandler;
    
    public class EchoServer {
    	private int port=8081;
    	private void run() {
    		  EventLoopGroup bossGroup = new NioEventLoopGroup();
    	      EventLoopGroup workerGroup = new NioEventLoopGroup();
    	        try {
    	            //创建ServerBootstrap对象，它是Netty用于启动NIO服务端的辅助启动类，目的是降低服务端的开发复杂度。
    	            ServerBootstrap bootstrap = new ServerBootstrap();
    
    	            bootstrap
    	                    //调用ServerBootstrap的group方法，将两个NIO线程组当作入参传递到ServerBootstrap中。
    	                    .group(bossGroup, workerGroup)
    	                    //接着设置创建的Channel为NioServerSocketChannel,它的功能对应于JDK NIO类库中的ServerSocketChannel类。
    	                    .channel(NioServerSocketChannel.class)
    	                    .handler(new LoggingHandler(LogLevel.INFO))
    	                    //最后绑定I/O事件的处理类ChannelInitializer，它的作用类似于Reactor模式中的Handler类，
    	                    //主要用于处理网络I/O事件，例如记录日志、对消息进行编解码等。
    	                    .childHandler(new ChannelInitializer<SocketChannel>() {
    	                        @Override
    	                        protected void initChannel(SocketChannel socketChannel) throws Exception {
    	                            socketChannel.pipeline()
    	                                    //创建消息解码器，获取消息长度
    	                                    .addLast(new ProtobufVarint32FrameDecoder())
    	                                    //指定消息类型
    	                                    .addLast(new ProtobufDecoder(UserInfo.UserMsg.getDefaultInstance()))
    	                                    //消息头置长度
    	                                    .addLast(new ProtobufVarint32LengthFieldPrepender())
    	                                    //创建消息编码器
    	                                    .addLast(new ProtobufEncoder())
    	                                    //消息的处理
    	                                    .addLast(new EchoServerHandler());
    	                        }
    	                    });
    	            //服务端启动辅助类配置完成之后，调用它的bind 方法绑定监听端口，
    	            //随后，调用它的同步阻塞方法sync等待绑定操作完成。
    	            //完成之后Netty会返回一个ChannelFuture, 它的功能类似于JDK的java.util.concurrent.Future，主要用于异步操作的通知回调。
    	            //使用f.channel.closeFuture().syncO方法进行阻塞，等待服务端链路关闭之后main函数才退出。
    	            ChannelFuture sync = bootstrap.bind(port).sync();
    
    	            sync.channel().closeFuture().sync();
    	        } catch (Exception e) {
    	            e.printStackTrace();
    	        } finally {
    	            //调用NIO线程组的shutdownGracefully 进行优雅退出，它会释放跟shutdownGracefully相关联的资源。
    	            bossGroup.shutdownGracefully();
    	            workerGroup.shutdownGracefully();
    	        }
    
    	}
    	
    	public static void main(String[] args) {
    		new EchoServer().run();
    	}
    }

服务端消息处理器:EchoServerHandler.java

package com.netty.server.two.handler;
    
    import com.netty.protobuf.UserInfo;
    import io.netty.channel.ChannelHandlerContext;
    import io.netty.channel.ChannelInboundHandlerAdapter;
    import io.netty.util.ReferenceCountUtil;
    
    public class EchoServerHandler extends ChannelInboundHandlerAdapter {
    	int count;
    
    	//当通道激活时
        @Override
        public void channelActive(ChannelHandlerContext ctx) throws Exception {
            System.out.println("连接的客户端地址:" + ctx.channel().remoteAddress());
            super.channelActive(ctx);
        }
    
    	//当通道读到数据时
        @Override
        public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
            try {
            	//拿到解码后的消息
            	UserInfo.UserMsg userMsg = (UserInfo.UserMsg) msg;
                System.out.println("Receive:[" + userMsg.toString() + "],count:[" + (++count) + "]");
                UserInfo.UserMsg.Builder builder =  userMsg.toBuilder().setState(1);
                ctx.writeAndFlush(builder);
            } finally {
                ReferenceCountUtil.release(msg);
            }
    
    
        }
    
    	//当通道异常时
        @Override
        public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
            cause.printStackTrace();
            ctx.close();
        }
    }

## 第四步:新建Netty 客户端程序启动入口及其消息处理器(Handler) ##

客户端程序入口:Echoclient.java

package com.netty.client.two;
    
    import com.netty.client.two.handler.EchoClientHandler;
    import com.netty.protobuf.UserInfo;
    
    import io.netty.bootstrap.Bootstrap;
    import io.netty.channel.ChannelFuture;
    import io.netty.channel.ChannelInitializer;
    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.codec.protobuf.ProtobufDecoder;
    import io.netty.handler.codec.protobuf.ProtobufEncoder;
    import io.netty.handler.codec.protobuf.ProtobufVarint32FrameDecoder;
    import io.netty.handler.codec.protobuf.ProtobufVarint32LengthFieldPrepender;
    
    public class Echoclient {
    
    	public static void main(String[] args) {
    		// TODO Auto-generated method stub
    		int port = 8081;
    		EventLoopGroup group = new NioEventLoopGroup();
            try {
                Bootstrap b = new Bootstrap();
                b.group(group)
                        .channel(NioSocketChannel.class)
                        .handler(new ChannelInitializer<SocketChannel>() {
                            @Override
                            protected void initChannel(SocketChannel socketChannel) throws Exception {
                                socketChannel.pipeline()
                                        .addLast(new ProtobufVarint32FrameDecoder())
                                        .addLast(new ProtobufDecoder(UserInfo.UserMsg.getDefaultInstance()))
                                        .addLast(new ProtobufVarint32LengthFieldPrepender())
                                        .addLast(new ProtobufEncoder())
                                        .addLast(new EchoClientHandler());
                            }
                        });
                ChannelFuture f = b.connect("127.0.0.1", port).sync();
    
                f.channel().closeFuture().sync();
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                group.shutdownGracefully();
            }
    	}
    
    }

客户端消息处理器:EchoClientHandler.java

package com.netty.client.two.handler;
    
    import com.netty.protobuf.UserInfo;
    
    import io.netty.channel.ChannelHandlerContext;
    import io.netty.channel.ChannelInboundHandlerAdapter;
    import io.netty.util.ReferenceCountUtil;
    
    public class EchoClientHandler extends ChannelInboundHandlerAdapter {
    	int count;
        String echo_req = "Hi,zhouchengxi,welcome to netty";
        UserInfo.UserMsg.Builder builder = UserInfo.UserMsg.newBuilder();
    
        @Override
        public void channelActive(ChannelHandlerContext ctx) throws Exception {
            for (int i = 1; i <= 10; i++) {
                UserInfo.UserMsg fangyan = builder.setId(1).setAge(i).setName("zhouchengxi" + i).build();
                ctx.writeAndFlush(fangyan);
            }
        }
    
        @Override
        public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
            try {
                UserInfo.UserMsg userMsg = (UserInfo.UserMsg) msg;
                System.out.println("Server:[" + userMsg.toString() + "]count:[" + (++count) + "]");
            } finally {
                ReferenceCountUtil.release(msg);
            }
        }
    
        @Override
        public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
            cause.printStackTrace();
            ctx.close();
        }
    }

## 第五步:自定义协议对应Java实体对象 ##

// Generated by the protocol buffer compiler.  DO NOT EDIT!
    // source: User.proto
    
    package com.netty.protobuf;
    
    public final class UserInfo {
      private UserInfo() {}
      public static void registerAllExtensions(
          com.google.protobuf.ExtensionRegistryLite registry) {
      }
    
      public static void registerAllExtensions(
          com.google.protobuf.ExtensionRegistry registry) {
        registerAllExtensions(
            (com.google.protobuf.ExtensionRegistryLite) registry);
      }
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          // @@protoc_insertion_point(interface_extends:UserMsg)
          com.google.protobuf.MessageOrBuilder {
    
        /**
         * <code>int32 id = 1;</code>
         * @return The id.
         */
        int getId();
    
        /**
         * <code>string name = 2;</code>
         * @return The name.
         */
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        /**
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         * @return The bytes for name.
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        com.google.protobuf.ByteString
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        /**
         * <code>int32 age = 3;</code>
         * @return The age.
         */
        int getAge();
    
        /**
         * <code>int32 state = 4;</code>
         * @return The state.
         */
        int getState();
      }
      /**
       * Protobuf type {@code UserMsg}
       */
      public static final class UserMsg extends
          com.google.protobuf.GeneratedMessageV3 implements
          // @@protoc_insertion_point(message_implements:UserMsg)
          UserMsgOrBuilder {
      private static final long serialVersionUID = 0L;
        // Use UserMsg.newBuilder() to construct.
        private UserMsg(com.google.protobuf.GeneratedMessageV3.Builder<?> builder) {
          super(builder);
        }
        private UserMsg() {
          name_ = "";
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        @SuppressWarnings({"unused"})
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                  break;
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                case 18: {
                  java.lang.String s = input.readStringRequireUtf8();
    
                  name_ = s;
                  break;
                }
                case 24: {
    
                  age_ = input.readInt32();
                  break;
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                case 32: {
    
                  state_ = input.readInt32();
                  break;
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                default: {
                  if (!parseUnknownField(
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                    done = true;
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                  break;
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            this.unknownFields = unknownFields.build();
            makeExtensionsImmutable();
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        }
    
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          public Builder mergeFrom(com.google.protobuf.Message other) {
            if (other instanceof com.netty.protobuf.UserInfo.UserMsg) {
              return mergeFrom((com.netty.protobuf.UserInfo.UserMsg)other);
            } else {
              super.mergeFrom(other);
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          public Builder mergeFrom(com.netty.protobuf.UserInfo.UserMsg other) {
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            } catch (com.google.protobuf.InvalidProtocolBufferException e) {
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              }
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          public Builder setName(
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            if (value == null) {
        throw new NullPointerException();
      }
      
            name_ = value;
            onChanged();
            return this;
          }
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           * <code>string name = 2;</code>
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            name_ = getDefaultInstance().getName();
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          private int age_ ;
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          // @@protoc_insertion_point(builder_scope:UserMsg)
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          @java.lang.Override
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          return PARSER;
        }
    
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      }
    
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      private static final 
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          getDescriptor() {
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      private static  com.google.protobuf.Descriptors.FileDescriptor
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    }

## 效果截图: ##

服务端:

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pob3V6aGl3ZW5nYW5n_size_16_color_FFFFFF_t_70][]

客户端:

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pob3V6aGl3ZW5nYW5n_size_16_color_FFFFFF_t_70 1][]

补充：针对自定义协议实体对象。

Java 代码示例：

// 按照定义的数据结构，创建一个对象
    UserInfo.UserMsg.Builder userInfo = UserInfo.UserMsg.newBuilder();
    userInfo.setId(1);
    userInfo.setName("zhouchenxi");
    userInfo.setAge(2);
    UserInfo.UserMsg userMsg = userInfo.build();
    // 将数据写到输出流
    ByteArrayOutputStream output = new ByteArrayOutputStream();
    userMsg.writeTo(output);
    // 将数据序列化后发送
    byte[] byteArray = output.toByteArray();
    // 接收到流并读取
    ByteArrayInputStream input = new ByteArrayInputStream(byteArray);
    // 反序列化
    UserInfo.UserMsg userInfo2 = UserInfo.UserMsg.parseFrom(input);
    System.out.println("id:" + userInfo2.getId());
    System.out.println("name:" + userInfo2.getName());
    System.out.println("age:" + userInfo2.getAge());

[Netty _google ProtoBuf]: https://blog.csdn.net/zhouzhiwengang/article/details/112187715
[https_blog.csdn.net_kunfeisang5551_article_details_107957256]: https://blog.csdn.net/kunfeisang5551/article/details/107957256
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pob3V6aGl3ZW5nYW5n_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20210104180239624.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pob3V6aGl3ZW5nYW5n,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pob3V6aGl3ZW5nYW5n_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20210104180250822.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pob3V6aGl3ZW5nYW5n,size_16,color_FFFFFF,t_70