Class AbstractChannel

java.lang.Object

io.netty.util.DefaultAttributeMap

io.netty.channel.AbstractChannel

All Implemented Interfaces:

Channel, ChannelOutboundInvoker, AttributeMap, Comparable<Channel>

Direct Known Subclasses:

AbstractEpollServerChannel, AbstractEpollStreamChannel, AbstractKQueueServerChannel, AbstractKQueueStreamChannel, AbstractNioChannel, AbstractOioChannel, AbstractServerChannel, EmbeddedChannel, EpollDatagramChannel, EpollDomainDatagramChannel, IoUringDatagramChannel, IoUringDomainSocketChannel, IoUringServerDomainSocketChannel, IoUringServerSocketChannel, IoUringSocketChannel, KQueueDatagramChannel, KQueueDomainDatagramChannel, LocalChannel

public abstract class AbstractChannel
extends DefaultAttributeMap
implements Channel

A skeletal Channel implementation.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected class	AbstractChannel.AbstractUnsafe	Channel.Unsafe implementation which sub-classes must extend and use.

Nested classes/interfaces inherited from interface Channel

Channel.Unsafe

Modifier and Type	Interface	Description
static interface	Channel.Unsafe	Unsafe operations that should never be called from user-code.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractChannel(Channel parent)	Creates a new instance.
protected	AbstractChannel(Channel parent, ChannelId id)	Creates a new instance.

Method Summary

Modifier and Type	Method	Description
ChannelFuture	closeFuture()	Returns the ChannelFuture which will be notified when this channel is closed.
final int	compareTo(Channel o)
protected abstract void	doBeginRead()	Schedule a read operation.
protected abstract void	doBind(SocketAddress localAddress)	Bind the Channel to the SocketAddress
protected abstract void	doClose()	Close the Channel
protected void	doDeregister()	Deregister the Channel from its EventLoop.
protected abstract void	doDisconnect()	Disconnect this Channel from its remote peer
protected void	doRegister()	Deprecated. use doRegister(ChannelPromise)
protected void	doRegister(ChannelPromise promise)	Is called after the Channel is registered with its EventLoop as part of the register process.
protected void	doShutdownOutput()	Called when conditions justify shutting down the output portion of the channel.
protected abstract void	doWrite(ChannelOutboundBuffer in)	Flush the content of the given buffer to the remote peer.
final boolean	equals(Object o)	Returns true if and only if the specified object is identical with this channel (i.e: this == o).
EventLoop	eventLoop()	Return the EventLoop this Channel was registered to.
protected Object	filterOutboundMessage(Object msg)	Invoked when a new message is added to a ChannelOutboundBuffer of this AbstractChannel, so that the Channel implementation converts the message to another.
final int	hashCode()	Returns the ID of this channel.
final ChannelId	id()	Returns the globally unique identifier of this Channel.
protected void	invalidateLocalAddress()	Deprecated. no use-case for this.
protected void	invalidateRemoteAddress()	Deprecated. no use-case for this.
protected abstract boolean	isCompatible(EventLoop loop)	Return true if the given EventLoop is compatible with this instance.
boolean	isRegistered()	Returns true if the Channel is registered with an EventLoop.
SocketAddress	localAddress()	Returns the local address where this channel is bound to.
protected abstract SocketAddress	localAddress0()	Returns the SocketAddress which is bound locally.
protected final int	maxMessagesPerWrite()
protected DefaultChannelPipeline	newChannelPipeline()	Returns a new DefaultChannelPipeline instance.
protected ChannelId	newId()	Returns a new DefaultChannelId instance.
protected abstract AbstractChannel.AbstractUnsafe	newUnsafe()	Create a new AbstractChannel.AbstractUnsafe instance which will be used for the life-time of the Channel
Channel	parent()	Returns the parent of this channel.
ChannelPipeline	pipeline()	Return the assigned ChannelPipeline.
SocketAddress	remoteAddress()	Returns the remote address where this channel is connected to.
protected abstract SocketAddress	remoteAddress0()	Return the SocketAddress which the Channel is connected to.
String	toString()	Returns the String representation of this channel.
Channel.Unsafe	unsafe()	Returns an internal-use-only object that provides unsafe operations.
protected void	validateFileRegion(DefaultFileRegion region, long position)
final ChannelPromise	voidPromise()	Return a special ChannelPromise which can be reused for different operations.

Methods inherited from class DefaultAttributeMap

attr, hasAttr

Modifier and Type	Method	Description
<T> Attribute<T>	attr(AttributeKey<T> key)	Get the Attribute for the given AttributeKey.
<T> boolean	hasAttr(AttributeKey<T> key)	Returns true if and only if the given Attribute exists in this AttributeMap.

Methods inherited from class Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface Channel

alloc, bind, bind, bytesBeforeUnwritable, bytesBeforeWritable, close, close, config, connect, connect, connect, connect, deregister, deregister, disconnect, disconnect, flush, getOption, isActive, isOpen, isWritable, metadata, newFailedFuture, newProgressivePromise, newPromise, newSucceededFuture, read, setOption, write, write, writeAndFlush, writeAndFlush

Modifier and Type	Method	Description
default ByteBufAllocator	alloc()	Return the assigned ByteBufAllocator which will be used to allocate ByteBufs.
default ChannelFuture	bind(SocketAddress localAddress)	Request to bind to the given SocketAddress and notify the ChannelFuture once the operation completes, either because the operation was successful or because of an error.
default ChannelFuture	bind(SocketAddress localAddress, ChannelPromise promise)	Request to bind to the given SocketAddress and notify the ChannelFuture once the operation completes, either because the operation was successful or because of an error.
default long	bytesBeforeUnwritable()	Get how many bytes can be written until Channel.isWritable() returns false.
default long	bytesBeforeWritable()	Get how many bytes must be drained from underlying buffers until Channel.isWritable() returns true.
default ChannelFuture	close()	Request to close the Channel and notify the ChannelFuture once the operation completes, either because the operation was successful or because of an error.
default ChannelFuture	close(ChannelPromise promise)	Request to close the Channel and notify the ChannelFuture once the operation completes, either because the operation was successful or because of an error.
ChannelConfig	config()	Returns the configuration of this channel.
default ChannelFuture	connect(SocketAddress remoteAddress)	Request to connect to the given SocketAddress and notify the ChannelFuture once the operation completes, either because the operation was successful or because of an error.
default ChannelFuture	connect(SocketAddress remoteAddress, ChannelPromise promise)	Request to connect to the given SocketAddress and notify the ChannelFuture once the operation completes, either because the operation was successful or because of an error.
default ChannelFuture	connect(SocketAddress remoteAddress, SocketAddress localAddress)	Request to connect to the given SocketAddress while bind to the localAddress and notify the ChannelFuture once the operation completes, either because the operation was successful or because of an error.
default ChannelFuture	connect(SocketAddress remoteAddress, SocketAddress localAddress, ChannelPromise promise)	Request to connect to the given SocketAddress while bind to the localAddress and notify the ChannelFuture once the operation completes, either because the operation was successful or because of an error.
default ChannelFuture	deregister()	Request to deregister from the previous assigned EventExecutor and notify the ChannelFuture once the operation completes, either because the operation was successful or because of an error.
default ChannelFuture	deregister(ChannelPromise promise)	Request to deregister from the previous assigned EventExecutor and notify the ChannelFuture once the operation completes, either because the operation was successful or because of an error.
default ChannelFuture	disconnect()	Request to disconnect from the remote peer and notify the ChannelFuture once the operation completes, either because the operation was successful or because of an error.
default ChannelFuture	disconnect(ChannelPromise promise)	Request to disconnect from the remote peer and notify the ChannelFuture once the operation completes, either because the operation was successful or because of an error.
default Channel	flush()	Request to flush all pending messages via this ChannelOutboundInvoker.
default <T> T	getOption(ChannelOption<T> option)	Return the value of the given ChannelOption
boolean	isActive()	Return true if the Channel is active and so connected.
boolean	isOpen()	Returns true if the Channel is open and may get active later
default boolean	isWritable()	Returns true if and only if the I/O thread will perform the requested write operation immediately.
ChannelMetadata	metadata()	Return the ChannelMetadata of the Channel which describe the nature of the Channel.
default ChannelFuture	newFailedFuture(Throwable cause)	Create a new ChannelFuture which is marked as failed already.
default ChannelProgressivePromise	newProgressivePromise()	Return an new ChannelProgressivePromise
default ChannelPromise	newPromise()	Return a new ChannelPromise.
default ChannelFuture	newSucceededFuture()	Create a new ChannelFuture which is marked as succeeded already.
default Channel	read()	Request to Read data from the Channel into the first inbound buffer, triggers an ChannelInboundHandler.channelRead(ChannelHandlerContext, Object) event if data was read, and triggers a channelReadComplete event so the handler can decide to continue reading.
default <T> boolean	setOption(ChannelOption<T> option, T value)	Sets a configuration property with the specified name and value.
default ChannelFuture	write(Object msg)	Request to write a message via this ChannelHandlerContext through the ChannelPipeline.
default ChannelFuture	write(Object msg, ChannelPromise promise)	Request to write a message via this ChannelHandlerContext through the ChannelPipeline.
default ChannelFuture	writeAndFlush(Object msg)	Shortcut for call ChannelOutboundInvoker.write(Object) and ChannelOutboundInvoker.flush().
default ChannelFuture	writeAndFlush(Object msg, ChannelPromise promise)	Shortcut for call ChannelOutboundInvoker.write(Object, ChannelPromise) and ChannelOutboundInvoker.flush().

Constructor Details

AbstractChannel

protected AbstractChannel(Channel parent)

Creates a new instance.

Parameters:

parent - the parent of this channel. null if there's no parent.

AbstractChannel

protected AbstractChannel(Channel parent,
 ChannelId id)

Creates a new instance.

Parameters:

parent - the parent of this channel. null if there's no parent.

Method Details

maxMessagesPerWrite

protected final int maxMessagesPerWrite()

id

public final ChannelId id()

Description copied from interface: Channel

Returns the globally unique identifier of this Channel.

Specified by:

id in interface Channel

newId

protected ChannelId newId()

Returns a new DefaultChannelId instance. Subclasses may override this method to assign custom ChannelIds to Channels that use the AbstractChannel(Channel) constructor.

newChannelPipeline

protected DefaultChannelPipeline newChannelPipeline()

Returns a new DefaultChannelPipeline instance.

parent

public Channel parent()

Description copied from interface: Channel

Returns the parent of this channel.

Specified by:

parent in interface Channel

Returns:

the parent channel. null if this channel does not have a parent channel.

pipeline

public ChannelPipeline pipeline()

Description copied from interface: Channel

Return the assigned ChannelPipeline.

Specified by:

pipeline in interface Channel

eventLoop

public EventLoop eventLoop()

Description copied from interface: Channel

Return the EventLoop this Channel was registered to.

Specified by:

eventLoop in interface Channel

localAddress

public SocketAddress localAddress()

Description copied from interface: Channel

Returns the local address where this channel is bound to. The returned SocketAddress is supposed to be down-cast into more concrete type such as InetSocketAddress to retrieve the detailed information.

Specified by:

localAddress in interface Channel

Returns:

the local address of this channel. null if this channel is not bound.

invalidateLocalAddress

@Deprecated
protected void invalidateLocalAddress()

Deprecated.

no use-case for this.

remoteAddress

public SocketAddress remoteAddress()

Description copied from interface: Channel

Returns the remote address where this channel is connected to. The returned SocketAddress is supposed to be down-cast into more concrete type such as InetSocketAddress to retrieve the detailed information.

Specified by:

remoteAddress in interface Channel

Returns:

the remote address of this channel. null if this channel is not connected. If this channel is not connected but it can receive messages from arbitrary remote addresses (e.g. DatagramChannel, use DefaultAddressedEnvelope.recipient() to determine the origination of the received message as this method will return null.

invalidateRemoteAddress

@Deprecated
protected void invalidateRemoteAddress()

Deprecated.

no use-case for this.

isRegistered

public boolean isRegistered()

Description copied from interface: Channel

Returns true if the Channel is registered with an EventLoop.

Specified by:

isRegistered in interface Channel

closeFuture

public ChannelFuture closeFuture()

Description copied from interface: Channel

Returns the ChannelFuture which will be notified when this channel is closed. This method always returns the same future instance.

Specified by:

closeFuture in interface Channel

unsafe

public Channel.Unsafe unsafe()

Description copied from interface: Channel

Returns an internal-use-only object that provides unsafe operations.

Specified by:

unsafe in interface Channel

newUnsafe

protected abstract AbstractChannel.AbstractUnsafe newUnsafe()

Create a new AbstractChannel.AbstractUnsafe instance which will be used for the life-time of the Channel

hashCode

public final int hashCode()

Returns the ID of this channel.

Overrides:

hashCode in class Object

equals

public final boolean equals(Object o)

Returns true if and only if the specified object is identical with this channel (i.e: this == o).

Overrides:

equals in class Object

compareTo

public final int compareTo(Channel o)

Specified by:

compareTo in interface Comparable<Channel>

toString

public String toString()

Returns the String representation of this channel. The returned string contains the ID, local address, and remote address of this channel for easier identification.

Overrides:

toString in class Object

voidPromise

public final ChannelPromise voidPromise()

Description copied from interface: ChannelOutboundInvoker

Return a special ChannelPromise which can be reused for different operations.

It's only supported to use it for ChannelOutboundInvoker.write(Object, ChannelPromise).

Be aware that the returned ChannelPromise will not support most operations and should only be used if you want to save an object allocation for every write operation. You will not be able to detect if the operation was complete, only if it failed as the implementation will call ChannelPipeline.fireExceptionCaught(Throwable) in this case.

Be aware this is an expert feature and should be used with care!

Specified by:

voidPromise in interface Channel

Specified by:

voidPromise in interface ChannelOutboundInvoker

isCompatible

protected abstract boolean isCompatible(EventLoop loop)

Return true if the given EventLoop is compatible with this instance.

localAddress0

protected abstract SocketAddress localAddress0()

Returns the SocketAddress which is bound locally.

remoteAddress0

protected abstract SocketAddress remoteAddress0()

Return the SocketAddress which the Channel is connected to.

doRegister

@Deprecated
protected void doRegister()
                   throws Exception

Deprecated.

use doRegister(ChannelPromise)

Is called after the Channel is registered with its EventLoop as part of the register process. Subclasses may override this method

Throws:

Exception

doRegister

protected void doRegister(ChannelPromise promise)

Is called after the Channel is registered with its EventLoop as part of the register process. Subclasses may override this method

Parameters:

promise - ChannelPromise that must be notified once done to continue the registration.

doBind

protected abstract void doBind(SocketAddress localAddress)
                        throws Exception

Bind the Channel to the SocketAddress

Throws:

Exception

doDisconnect

protected abstract void doDisconnect()
                              throws Exception

Disconnect this Channel from its remote peer

Throws:

Exception

doClose

protected abstract void doClose()
                         throws Exception

Close the Channel

Throws:

Exception

doShutdownOutput

protected void doShutdownOutput()
                         throws Exception

Called when conditions justify shutting down the output portion of the channel. This may happen if a write operation throws an exception.

Throws:

Exception

doDeregister

protected void doDeregister()
                     throws Exception

Deregister the Channel from its EventLoop. Sub-classes may override this method

Throws:

Exception

doBeginRead

protected abstract void doBeginRead()
                             throws Exception

Schedule a read operation.

Throws:

Exception

doWrite

protected abstract void doWrite(ChannelOutboundBuffer in)
                         throws Exception

Flush the content of the given buffer to the remote peer.

Throws:

Exception

filterOutboundMessage

protected Object filterOutboundMessage(Object msg)
                                throws Exception

Invoked when a new message is added to a ChannelOutboundBuffer of this AbstractChannel, so that the Channel implementation converts the message to another. (e.g. heap buffer -> direct buffer)

Throws:

Exception

validateFileRegion

protected void validateFileRegion(DefaultFileRegion region,
 long position)
                           throws IOException

Throws:

IOException