org.jboss.netty.channel
Class ChannelLocal<T>

java.lang.Object
  org.jboss.netty.channel.ChannelLocal<T>

public class ChannelLocal<T>
extends Object

A global variable that is local to a Channel. Think of this as a variation of ThreadLocal whose key is a Channel rather than a Thread.currentThread(). One difference is that you always have to specify the Channel to access the variable.

Alternatively, you might want to use the ChannelHandlerContext.attachment property, which performs better.

Version:

$Rev: 2080 $, $Date: 2010-01-26 18:04:19 +0900 (Tue, 26 Jan 2010) $

Author:

The Netty Project, Trustin Lee

Constructor Summary

ChannelLocal()
Creates a Channel local variable.

Method Summary

T	get(Channel channel) Returns the value of this variable.
protected T	initialValue(Channel channel) Returns the initial value of the variable.
T	remove(Channel channel) Removes the variable and returns the removed value.
T	set(Channel channel, T value) Sets the value of this variable.
T	setIfAbsent(Channel channel, T value) Sets the value of this variable only when no value was set.

Methods inherited from class java.lang.Object

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

Constructor Detail

ChannelLocal

public ChannelLocal()

Creates a Channel local variable.

Method Detail

initialValue

protected T initialValue(Channel channel)

Returns the initial value of the variable. By default, it returns null. Override it to change the initial value.

get

public T get(Channel channel)

Returns the value of this variable.

set

public T set(Channel channel,
             T value)

Sets the value of this variable.

Returns:

the old value. null if there was no old value.

setIfAbsent

public T setIfAbsent(Channel channel,
                     T value)

Sets the value of this variable only when no value was set.

Returns:

null if the specified value was set. An existing value if failed to set.

remove

public T remove(Channel channel)

Removes the variable and returns the removed value. If no value was set, this method returns the return value of initialValue(Channel), which is null by default.

Returns:

the removed value. an initial value (by default null) if no value was set.