netty-基本类

SimpleChannelInboundHandler channelInactive userEventTriggered channelRead0

ChannelInitializer

SpringBeanFactory

@Component @PostConstruct @PreDestroy

IdleStateHandler

HeartbeatDecoder ByteToMessageDecoder

@Configuration

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ChannelRead channelRead0 messageReceived

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org.jboss.netty.bootstrap.; First, in Netty 3.X the packages were from org.jboss.netty. io.netty.bootstrap.ServerBootstrap; But started Netty 4.X the packeages are from io.netty.*

Now, if you are using Netty 4.X to read message use the method

ChannelRead(ChannelHandleContext ctx, Object msg) { ... } inherited from ChannelInboundHandlerAdapter class. The method:

messageReceived(ChannelHandlerContext, I) { ...} was used in Netty 3.X version.

ByteBuf ByteBuf buf = Unpooled.buffer();

池化buffer Netty4引入了一种高效缓存池（buffer pool），它是结合了 buddy allocation 以及 slab allocation 的 jemalloc 的变体。

减少buffer的频繁分配及回收致使的GC压力 减小新建buffer时0值填充产生的内存带宽消耗 及时回收直接内存（direct buffers） 为了能够利用这些特性，用户都应该使用 ByteBufAllocator 获取buffer，除非你但愿使用非池化buffer:

Channel channel = ...; ByteBufAllocator alloc = channel.alloc(); ByteBuf buf = alloc.buffer(512);

ChannelInboundHandlerAdapter channelRead （ChannelHandlerContext ctx, Object msg） channelReadComplete(ChannelHandlerContext ctx) exceptionCaught(ChannelHandlerContext ctx, Throwable cause)

Netty的核心组件 在本节中我将要讨论Netty的主要构件块： Channel； 回调； Future； 事件和ChannelHandler。 ChannelFutureListener ChannelFuture