io.netty.channel

Class SimpleUserEventChannelHandler<I>

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

io.netty.channel.SimpleUserEventChannelHandler<I>

All Implemented Interfaces:

ChannelHandler, ChannelInboundHandler

public abstract class SimpleUserEventChannelHandler<I>
extends ChannelInboundHandlerAdapter

ChannelInboundHandlerAdapter which allows to conveniently only handle a specific type of user events. For example, here is an implementation which only handle String user events.

     public class StringEventHandler extends
             SimpleUserEventChannelHandler<String> {

          @Override
         protected void eventReceived(ChannelHandlerContext ctx, String evt)
                 throws Exception {
             System.out.println(evt);
         }
     }
 

Be aware that depending of the constructor parameters it will release all handled events by passing them to ReferenceCountUtil.release(Object). In this case you may need to use ReferenceCountUtil.retain(Object) if you pass the object to the next handler in the ChannelPipeline.

Nested Class Summary

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

ChannelHandler.Sharable

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	SimpleUserEventChannelHandler() see SimpleUserEventChannelHandler(boolean) with true as boolean parameter.
protected	SimpleUserEventChannelHandler(boolean autoRelease) Create a new instance which will try to detect the types to match out of the type parameter of the class.
protected	SimpleUserEventChannelHandler(Class<? extends I> eventType) see SimpleUserEventChannelHandler(Class, boolean) with true as boolean value.
protected	SimpleUserEventChannelHandler(Class<? extends I> eventType, boolean autoRelease) Create a new instance

Method Summary

Modifier and Type	Method and Description
protected boolean	acceptEvent(Object evt) Returns true if the given user event should be handled.
protected abstract void	eventReceived(ChannelHandlerContext ctx, I evt) Is called for each user event triggered of type I.
void	userEventTriggered(ChannelHandlerContext ctx, Object evt) Calls ChannelHandlerContext.fireUserEventTriggered(Object) to forward to the next ChannelInboundHandler in the ChannelPipeline.

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

SimpleUserEventChannelHandler

protected SimpleUserEventChannelHandler()

see SimpleUserEventChannelHandler(boolean) with true as boolean parameter.

SimpleUserEventChannelHandler

protected SimpleUserEventChannelHandler(boolean autoRelease)

Create a new instance which will try to detect the types to match out of the type parameter of the class.

Parameters:

autoRelease - true if handled events should be released automatically by passing them to ReferenceCountUtil.release(Object).

SimpleUserEventChannelHandler

protected SimpleUserEventChannelHandler(Class<? extends I> eventType)

see SimpleUserEventChannelHandler(Class, boolean) with true as boolean value.

SimpleUserEventChannelHandler

protected SimpleUserEventChannelHandler(Class<? extends I> eventType,
                                        boolean autoRelease)

Create a new instance

Parameters:

eventType - The type of events to match

autoRelease - true if handled events should be released automatically by passing them to ReferenceCountUtil.release(Object).

Method Detail

acceptEvent

protected boolean acceptEvent(Object evt)
                       throws Exception

Returns true if the given user event should be handled. If false it will be passed to the next ChannelInboundHandler in the ChannelPipeline.

Throws:

Exception

userEventTriggered

public final void userEventTriggered(ChannelHandlerContext ctx,
                                     Object evt)
                              throws Exception

Description copied from class: ChannelInboundHandlerAdapter

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

Specified by:

userEventTriggered in interface ChannelInboundHandler

Overrides:

userEventTriggered in class ChannelInboundHandlerAdapter

Throws:

Exception

eventReceived

protected abstract void eventReceived(ChannelHandlerContext ctx,
                                      I evt)
                               throws Exception

Is called for each user event triggered of type I.

Parameters:

ctx - the ChannelHandlerContext which this SimpleUserEventChannelHandler belongs to

evt - the user event to handle

Throws:

Exception - is thrown if an error occurred