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:
编解码高效，性能高；
序列化之后码流小
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
/** * 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 } }
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~
