io.netty.handler.codec.http2

Class Http2MultiplexCodec

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

io.netty.channel.ChannelDuplexHandler

io.netty.handler.codec.http2.Http2MultiplexCodec

All Implemented Interfaces:

io.netty.channel.ChannelHandler, io.netty.channel.ChannelInboundHandler, io.netty.channel.ChannelOutboundHandler

@UnstableApi
public final class Http2MultiplexCodec
extends io.netty.channel.ChannelDuplexHandler

An HTTP/2 handler that creates child channels for each stream. Creating outgoing streams is not yet supported. Server-side HTTP to HTTP/2 upgrade is supported in conjunction with Http2ServerUpgradeCodec; the necessary HTTP-to-HTTP/2 conversion is performed automatically.

This API is very immature. The Http2Connection-based API is currently preferred over this API. This API is targeted to eventually replace or reduce the need for the Http2Connection-based API.

This handler notifies the pipeline of channel events, such as Http2GoAwayFrame. It is also capable of writing such messages. Directly writing Http2StreamFrames for this handler is unsupported.

Child Channels

When a new stream is created, a new Channel is created for it. Applications send and receive Http2StreamFrames on the created channel. The Http2StreamFrame.stream() is expected to be null, but the channel can use the field for its own bookkeeping. ByteBufs cannot be processed by the channel; all writes that reach the head of the pipeline must be an instance of Http2StreamFrame. Writes that reach the head of the pipeline are processed directly by this handler and cannot be intercepted.

The child channel will be notified of user events that impact the stream, such as Http2GoAwayFrame and Http2ResetFrame, as soon as they occur. Although Http2GoAwayFrame and Http2ResetFrame signify that the remote is ignoring further communication, closing of the channel is delayed until any inbound queue is drained with Channel.read(), which follows the default behavior of channels in Netty. Applications are free to close the channel in response to such events if they don't have use for any queued messages.

ChannelConfig.setMaxMessagesPerRead(int) and ChannelConfig.setAutoRead(boolean) are supported.

Nested Class Summary

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

io.netty.channel.ChannelHandler.Sharable

Constructor Summary

Constructors

Constructor and Description
Http2MultiplexCodec(boolean server, io.netty.channel.ChannelHandler streamHandler) Construct a new handler whose child channels run in the same event loop as this handler.
Http2MultiplexCodec(boolean server, io.netty.channel.ChannelHandler streamHandler, io.netty.channel.EventLoopGroup streamGroup) Construct a new handler whose child channels run in a different event loop.

Method Summary

Methods

Modifier and Type	Method and Description
void	channelReadComplete(io.netty.channel.ChannelHandlerContext ctx) Notifies any child streams of the read completion.
void	exceptionCaught(io.netty.channel.ChannelHandlerContext ctx, Throwable cause)
void	flush(io.netty.channel.ChannelHandlerContext ctx)
void	handlerAdded(io.netty.channel.ChannelHandlerContext ctx) Save context and load any dependencies.
void	handlerRemoved(io.netty.channel.ChannelHandlerContext ctx) Clean up any dependencies.
void	userEventTriggered(io.netty.channel.ChannelHandlerContext ctx, Object evt) Handles the cleartext HTTP upgrade event.
void	write(io.netty.channel.ChannelHandlerContext ctx, Object msg, io.netty.channel.ChannelPromise promise) Processes all Http2Frames.

Methods inherited from class io.netty.channel.ChannelDuplexHandler

bind, close, connect, deregister, disconnect, read

Methods inherited from class io.netty.channel.ChannelInboundHandlerAdapter

channelActive, channelInactive, channelRead, channelRegistered, channelUnregistered, channelWritabilityChanged

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

isSharable

Methods inherited from class java.lang.Object

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

Constructor Detail

Http2MultiplexCodec

public Http2MultiplexCodec(boolean server,
                   io.netty.channel.ChannelHandler streamHandler)

Construct a new handler whose child channels run in the same event loop as this handler.

Parameters:

server - true this is a server

streamHandler - the handler added to channels for remotely-created streams. It must be ChannelHandler.Sharable.

Http2MultiplexCodec

public Http2MultiplexCodec(boolean server,
                   io.netty.channel.ChannelHandler streamHandler,
                   io.netty.channel.EventLoopGroup streamGroup)

Construct a new handler whose child channels run in a different event loop.

Parameters:

server - true this is a server

streamHandler - the handler added to channels for remotely-created streams. It must be ChannelHandler.Sharable.

streamGroup - event loop for registering child channels

Method Detail

handlerAdded

public void handlerAdded(io.netty.channel.ChannelHandlerContext ctx)
                  throws Exception

Save context and load any dependencies.

Specified by:

handlerAdded in interface io.netty.channel.ChannelHandler

Overrides:

handlerAdded in class io.netty.channel.ChannelHandlerAdapter

Throws:

Exception

handlerRemoved

public void handlerRemoved(io.netty.channel.ChannelHandlerContext ctx)
                    throws Exception

Clean up any dependencies.

Specified by:

handlerRemoved in interface io.netty.channel.ChannelHandler

Overrides:

handlerRemoved in class io.netty.channel.ChannelHandlerAdapter

Throws:

Exception

userEventTriggered

public void userEventTriggered(io.netty.channel.ChannelHandlerContext ctx,
                      Object evt)
                        throws Exception

Handles the cleartext HTTP upgrade event. If an upgrade occurred, sends a simple response via HTTP/2 on stream 1 (the stream specifically reserved for cleartext HTTP upgrade).

Specified by:

userEventTriggered in interface io.netty.channel.ChannelInboundHandler

Overrides:

userEventTriggered in class io.netty.channel.ChannelInboundHandlerAdapter

Throws:

Exception

exceptionCaught

public void exceptionCaught(io.netty.channel.ChannelHandlerContext ctx,
                   Throwable cause)

Specified by:

exceptionCaught in interface io.netty.channel.ChannelHandler

Specified by:

exceptionCaught in interface io.netty.channel.ChannelInboundHandler

Overrides:

exceptionCaught in class io.netty.channel.ChannelInboundHandlerAdapter

flush

public void flush(io.netty.channel.ChannelHandlerContext ctx)

Specified by:

flush in interface io.netty.channel.ChannelOutboundHandler

Overrides:

flush in class io.netty.channel.ChannelDuplexHandler

write

public void write(io.netty.channel.ChannelHandlerContext ctx,
         Object msg,
         io.netty.channel.ChannelPromise promise)

Processes all Http2Frames. Http2StreamFrames may only originate in child streams.

Specified by:

write in interface io.netty.channel.ChannelOutboundHandler

Overrides:

write in class io.netty.channel.ChannelDuplexHandler

channelReadComplete

public void channelReadComplete(io.netty.channel.ChannelHandlerContext ctx)

Notifies any child streams of the read completion.

Specified by:

channelReadComplete in interface io.netty.channel.ChannelInboundHandler

Overrides:

channelReadComplete in class io.netty.channel.ChannelInboundHandlerAdapter