Netty中序列化框架MessagePack的简单实现
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.msgpackgroupId>
<artifactId>msgpackartifactId>
<version>0.6.12version>
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 [email protected]
*
*/
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 [email protected]
*
*/
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 [email protected]
*
*/
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 [email protected]
*
*/
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 [email protected]
*
*/
@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~