将 netty 与业务逻辑结合使用

Using netty with business logic

我对 netty 的使用经验不多,对 ChannelPipeline 的文档有疑问。这是它的确切含义:

 static final EventExecutorGroup group = new DefaultEventExecutorGroup(16);
 ...

 ChannelPipeline pipeline = ch.pipeline();

 pipeline.addLast("decoder", new MyProtocolDecoder());
 pipeline.addLast("encoder", new MyProtocolEncoder());

 // Tell the pipeline to run MyBusinessLogicHandler's event handler methods
 // in a different thread than an I/O thread so that the I/O thread is not blocked by
 // a time-consuming task.
 // If your business logic is fully asynchronous or finished very quickly, you don't
 // need to specify a group.
 pipeline.addLast(group, "handler", new MyBusinessLogicHandler());

我不太明白 MyBusinessLogicHandler class。它应该实施 DuplexChannelHandler 还是其他什么?例如,在我的特殊情况下,我有以下 class:

public class Packet{}

我想将一些字节序列解码成 Packet,给 MyBusinessLogicHandler 产生一些 Packet。然后再次将其编码为字节流以发送回客户端。我目前是这样看的:

public class MyBusinessLogicHandler extends SimpleChannelInboundHandler<MyModel>{
    public void channelRead0(ChannelHandlerContext ctx, Packet msg){
         Packet rslt = null;
         //Do some complicated business logic
         ctx.write(rslt);
    }
}

我不确定这是否是在 netty 中做事的常用方法。你能澄清一下吗?

是的。这是实现 MyBusinessLogicHandler 的完全正确的方法。您不需要 DuplexChannelHandler,因为在您的管道中您已经 MyProtocolEncoder(我想实现了 ChannelOutboundHandler)。 因此,当您调用 ctx.write(rslt) 时,您会触发出站处理程序的写入事件。

DuplexChannelHandler 仅在您想在同一个 class 中同时实现编码器和解码器的情况下才有用。例如,您可以加入 MyProtocolEncoderMyProtocolDecoder.