NettyIdleStateKeepAliveHandler (Core XMPP Server 4.9.2 API)

java.lang.Object
- io.netty.channel.ChannelHandlerAdapter
- - io.netty.channel.ChannelInboundHandlerAdapter
  - - io.netty.channel.ChannelDuplexHandler
    - - org.jivesoftware.openfire.nio.NettyIdleStateKeepAliveHandler

All Implemented Interfaces:

io.netty.channel.ChannelHandler, io.netty.channel.ChannelInboundHandler, io.netty.channel.ChannelOutboundHandler
```
public class NettyIdleStateKeepAliveHandler
extends io.netty.channel.ChannelDuplexHandler
```
A NettyIdleStateKeepAliveHandler listens for IdleStateEvents triggered by an IdleStateHandler. When invoked, the existence of a flag on the ChannelHandlerContext is determined. If this flag does not exist, then a keep-alive check if performed and the flag is set. If the does exist, then it is assumed that the peer failed the keep-alive check and the connection should be closed. The keep-alive check is implemented as an XMPP ping request. XMPP entities must respond with either an IQ result or an IQ error (feature-unavailable) stanza upon receiving the XMPP ping stanza. Both responses will be received by Openfire. As any inbound data will cause the flag to be reset, the connection will no longer be deemed 'idle'. Entities that do not respond to the IQ Ping stanzas can be considered dead, and their connection will be closed when the IdleStateHandler triggers the second idle event in a row. Note that whitespace pings that are sent by XMPP entities will also cause the connection idle count to be reset.

Author:

Alex Gidman

See Also:

IdleStateEvent, IdleStateHandler

Nested Class Summary
- Nested classes/interfaces inherited from interface io.netty.channel.ChannelHandler
  io.netty.channel.ChannelHandler.Sharable

Constructor Summary

Constructors
Constructor Description

NettyIdleStateKeepAliveHandler(boolean clientConnection)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`userEventTriggered(io.netty.channel.ChannelHandlerContext ctx, Object evt)`	Processes IdleStateEvents triggered by an IdleStateHandler.

Methods inherited from class io.netty.channel.ChannelDuplexHandler
bind, close, connect, deregister, disconnect, flush, read, write

Methods inherited from class io.netty.channel.ChannelInboundHandlerAdapter
channelActive, channelInactive, channelRead, channelReadComplete, channelRegistered, channelUnregistered, channelWritabilityChanged, exceptionCaught

Methods inherited from class io.netty.channel.ChannelHandlerAdapter
ensureNotSharable, handlerAdded, handlerRemoved, isSharable

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface io.netty.channel.ChannelHandler
handlerAdded, handlerRemoved

- Constructor Detail
  - NettyIdleStateKeepAliveHandler
```
public NettyIdleStateKeepAliveHandler(boolean clientConnection)
```
- Method Detail
  - userEventTriggered
```
public void userEventTriggered(io.netty.channel.ChannelHandlerContext ctx,
                               Object evt)
                        throws Exception
```
    Processes IdleStateEvents triggered by an IdleStateHandler. If the IdleStateEvent is an idle read state, the Netty channel is closed. If the IdleStateEvent is an idle write state, an XMPP ping request is sent to the remote entity.
    
    Specified by:
    
    userEventTriggered in interface io.netty.channel.ChannelInboundHandler
    
    Overrides:
    
    userEventTriggered in class io.netty.channel.ChannelInboundHandlerAdapter
    
    Parameters:
    
    ctx - ChannelHandlerContext
    
    evt - Event caught, expect IdleStateEvent
    
    Throws:
    
    Exception - when attempting to deliver ping packet