io.netty.channel

Class ChannelInitializer<C extends Channel>

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInitializer<C>

Type Parameters:

C - A sub-type of Channel

All Implemented Interfaces:

ChannelHandler

@ChannelHandler.Sharable
public abstract class ChannelInitializer<C extends Channel>
extends ChannelHandlerAdapter

A special ChannelHandler which offers an easy way to initialize a Channel once it was registered to its EventLoop. Implementations are most often used in the context of AbstractBootstrap.handler(ChannelHandler) , AbstractBootstrap.handler(ChannelHandler) and ServerBootstrap.childHandler(ChannelHandler) to setup the ChannelPipeline of a Channel.

 public class MyChannelInitializer extends ChannelInitializer {
     public void initChannel(Channel channel) {
         channel.pipeline().addLast("myHandler", new MyHandler());
     }
 }

 ServerBootstrap bootstrap = ...;
 ...
 bootstrap.childHandler(new MyChannelInitializer());
 ...
 

Be aware that this class is marked as ChannelHandler.Sharable and so the implementation must be safe to be re-used.

Nested Class Summary

Nested classes/interfaces inherited from interface io.netty.channel.ChannelHandler

ChannelHandler.Sharable, ChannelHandler.Skip

Constructor Summary

Constructors

Constructor and Description
ChannelInitializer()

Method Summary

Methods

Modifier and Type	Method and Description
void	channelRegistered(ChannelHandlerContext ctx) Calls ChannelHandlerContext.fireChannelRegistered() to forward to the next ChannelHandler in the ChannelPipeline.
protected abstract void	initChannel(C ch) This method will be called once the Channel was registered.

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

bind, channelActive, channelInactive, channelRead, channelReadComplete, channelUnregistered, channelWritabilityChanged, close, connect, deregister, disconnect, exceptionCaught, flush, handlerAdded, handlerRemoved, isSharable, read, userEventTriggered, write

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ChannelInitializer

public ChannelInitializer()

Method Detail

initChannel

protected abstract void initChannel(C ch)
                             throws Exception

This method will be called once the Channel was registered. After the method returns this instance will be removed from the ChannelPipeline of the Channel.

Parameters:

ch - the Channel which was registered.

Throws:

Exception - is thrown if an error occurs. In that case the Channel will be closed.

channelRegistered

public final void channelRegistered(ChannelHandlerContext ctx)
                             throws Exception

Description copied from class: ChannelHandlerAdapter

Calls ChannelHandlerContext.fireChannelRegistered() to forward to the next ChannelHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.

Specified by:

channelRegistered in interface ChannelHandler

Overrides:

channelRegistered in class ChannelHandlerAdapter

Throws:

Exception