Netty中序列化框架MessagePack的简单实现

ゝ一纸荒年。 2022-02-20 06:15 292阅读 0赞

MessagePack是一个高效的二进制序列化框架，它像JSON一样支持不同语言间的数据交换，但是它的性能更快，序列化之后的码流也更小。MessagePack的特点如下:

1.  编解码高效，性能高；
2.  序列化之后码流小
3.  支持跨语言

# MessagePack使用 #

## 1.依赖 ##

使用maven构建项目

<dependency>
    	<groupId>org.msgpack</groupId>
    	<artifactId>msgpack</artifactId>
    	<version>0.6.12</version>
    </dependency>

## 2.创建编码和解码器 ##

**编码器**

/** * @param ctx 上下文 * @param msg 需要编码的对象 * @param out 编码后的数据 */
    @Override
    protected void encode(ChannelHandlerContext ctx, Object msg, ByteBuf out) throws Exception { 
    	
    	MessagePack msgpack = new MessagePack();
    	// 对对象进行序列化
    	byte[] raw = msgpack.write(msg);
    	// 返回序列化的数据
    	out.writeBytes(raw);
    }

**解码器**

/** * @param ctx 上下文 * @param msg 需要解码的数据 * @param out 解码列表 */
    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf msg, List<Object> out) throws Exception { 
    	final byte[] array;
    	final int length = msg.readableBytes();
    	array = new byte[length];
    	// 获取需要解码的字节数组
    	msg.getBytes(msg.readerIndex(), array,0,length);
    	MessagePack msgpack = new MessagePack();
    	// 反序列化并将结果保存到了解码列表中
    	out.add(msgpack.read(array));
    }

## 3.客户端 ##

**EchoClient**

/** * MsgPack 编解码器 * * @author 波波烤鸭 * @email dengpbs@163.com * */
    public class EchoClient { 
    
    	public static void main(String[] args) throws Exception { 
    		int port = 8080;
    		if (args != null && args.length > 0) { 
    			try { 
    				port = Integer.valueOf(args[0]);
    			} catch (NumberFormatException e) { 
    				// 采用默认值
    			}
    		}
    		new EchoClient().connector(port, "127.0.0.1",10);
    	}
    
    	public void connector(int port, String host,final int sendNumber) throws Exception { 
    		// 配置客户端NIO线程组
    		EventLoopGroup group = new NioEventLoopGroup();
    		try { 
    			Bootstrap b = new Bootstrap();
    			b.group(group).channel(NioSocketChannel.class)
    							.option(ChannelOption.TCP_NODELAY, true)
    							.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 3000)
    							.handler(new ChannelInitializer<SocketChannel>() { 
    
    				@Override
    				protected void initChannel(SocketChannel ch) throws Exception { 
    					//这里设置通过增加包头表示报文长度来避免粘包
    		            ch.pipeline().addLast("frameDecoder",new LengthFieldBasedFrameDecoder(1024, 0, 2,0,2));
    		            //增加解码器
    		            ch.pipeline().addLast("msgpack decoder",new MsgpackDecoder());
    		            //这里设置读取报文的包头长度来避免粘包
    		            ch.pipeline().addLast("frameEncoder",new LengthFieldPrepender(2));
    		            //增加编码器
    		            ch.pipeline().addLast("msgpack encoder",new MsgpackEncoder());
    					// 4.添加自定义的处理器
    					ch.pipeline().addLast(new EchoClientHandler(sendNumber));
    				}
    			});
    
    			// 发起异步连接操作
    			ChannelFuture f = b.connect(host, port).sync();
    			// 等待客户端链路关闭
    			f.channel().closeFuture().sync();
    		}catch(Exception e){ 
    			e.printStackTrace();
    		}  finally { 
    			// 优雅退出，释放NIO线程组
    			group.shutdownGracefully();
    		}
    	}
    
    }

**EchoClientHandler**

/** * DelimiterBasedFrameDecoder 案例 * 自定义处理器 * @author 波波烤鸭 * @email dengpbs@163.com * */
    public class EchoServerHandler extends ChannelHandlerAdapter{ 
    
    
    	@Override
    	public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { 
    		//UserInfo user = (UserInfo) msg;
    		System.out.println("server receive the msgpack message :"+msg);
    		//ctx.writeAndFlush(user);
    		ctx.writeAndFlush(msg);
    		
    	}
    	
    	@Override
    	public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { 
    		cause.printStackTrace();
    		ctx.close(); // 发生异常关闭链路
    	}
    }

## 4.服务端 ##

**EchoServer**

/** * MsgPack 编解码器 * 服务端 * @author 波波烤鸭 * @email dengpbs@163.com * */
    public class EchoServer { 
    
    	public void bind(int port) throws Exception { 
    		// 配置服务端的NIO线程组
    		// 服务端接受客户端的连接
    		NioEventLoopGroup bossGroup = new NioEventLoopGroup();
    		// 进行SocketChannel的网络读写
    		NioEventLoopGroup workerGroup = new NioEventLoopGroup();
    		try { 
    			ServerBootstrap b = new ServerBootstrap();
    			b.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class)
    					.option(ChannelOption.SO_BACKLOG, 100)
    					.handler(new LoggingHandler(LogLevel.INFO))
    					.childHandler(new ChannelInitializer<SocketChannel>() { 
    
    						@Override
    						protected void initChannel(SocketChannel ch) throws Exception { 
    							ch.pipeline().addLast("frameDecoder",new LengthFieldBasedFrameDecoder(65535, 0, 2,0,2));
    							// 添加msgpack的编码和解码器
    							ch.pipeline().addLast("msgpack decoder",new MsgpackDecoder());
    							ch.pipeline().addLast("frameEncoder",new LengthFieldPrepender(2));
    							ch.pipeline().addLast("msgpack encoder",new MsgpackEncoder());
    							// 添加自定义的处理器
    							ch.pipeline().addLast(new EchoServerHandler());
    
    						}
    					});
    
    			// 绑定端口，同步等待成功
    			ChannelFuture f = b.bind(port).sync();
    			// 等待服务端监听端口关闭
    			f.channel().closeFuture().sync();
    		}catch(Exception e){ 
    			e.printStackTrace();
    		} finally { 
    			// 优雅退出，释放线程池资源
    			bossGroup.shutdownGracefully();
    			workerGroup.shutdownGracefully();
    		}
    	}
    
    	public static void main(String[] args) throws Exception { 
    		int port = 8080;
    		if(args!=null && args.length > 0){ 
    			try{ 
    				port = Integer.valueOf(args[0]);
    			}catch(NumberFormatException e){ 
    				// 采用默认值
    			}
    		}
    		new EchoServer().bind(port);
    	}
    
    }

**EchoServerHandler**

## 5.注意点（POJO） ##

**消息类上加上注解Message**，还有就是必须要有默认的无参构造器

/** * Msgpack 中必须添加@Message注解 及 无参构造方法 * @author 波波烤鸭 * @email dengpbs@163.com * */
    @Message
    public class UserInfo { 
    
    
    	private String name;
    	
    	private int age;
    
    	public String getName() { 
    		return name;
    	}
    
    	public void setName(String name) { 
    		this.name = name;
    	}
    
    	public int getAge() { 
    		return age;
    	}
    
    	public void setAge(int age) { 
    		this.age = age;
    	}
    
    	@Override
    	public String toString() { 
    		return "UserInfo [name=" + name + ", age=" + age + "]";
    	}
    }

## 6.测试 ##

服务端输出

server receive the msgpack message :["bobo烤鸭:0",0]
    server receive the msgpack message :["bobo烤鸭:1",1]
    server receive the msgpack message :["bobo烤鸭:2",2]
    server receive the msgpack message :["bobo烤鸭:3",3]
    server receive the msgpack message :["bobo烤鸭:4",4]
    server receive the msgpack message :["bobo烤鸭:5",5]
    server receive the msgpack message :["bobo烤鸭:6",6]
    server receive the msgpack message :["bobo烤鸭:7",7]
    server receive the msgpack message :["bobo烤鸭:8",8]
    server receive the msgpack message :["bobo烤鸭:9",9]

客户端输出

Client receive the msgpack message :["bobo烤鸭:0",0]
    Client receive the msgpack message :["bobo烤鸭:1",1]
    Client receive the msgpack message :["bobo烤鸭:2",2]
    Client receive the msgpack message :["bobo烤鸭:3",3]
    Client receive the msgpack message :["bobo烤鸭:4",4]
    Client receive the msgpack message :["bobo烤鸭:5",5]
    Client receive the msgpack message :["bobo烤鸭:6",6]
    Client receive the msgpack message :["bobo烤鸭:7",7]
    Client receive the msgpack message :["bobo烤鸭:8",8]
    Client receive the msgpack message :["bobo烤鸭:9",9]

至此Netty中就可以通过MessagePack来处理序列化的情况了~