org.jboss.netty.channel
Class SimpleChannelHandler

java.lang.Object
  org.jboss.netty.channel.SimpleChannelHandler

All Implemented Interfaces:

ChannelDownstreamHandler, ChannelHandler, ChannelUpstreamHandler

Direct Known Subclasses:

BufferedWriteHandler, HttpContentEncoder, IdleStateAwareChannelHandler

public class SimpleChannelHandler
extends Object
implements ChannelUpstreamHandler, ChannelDownstreamHandler

A ChannelHandler which provides an individual handler method for each event type. This handler down-casts the received upstream or or downstream event into more meaningful sub-type event and calls an appropriate handler method with the down-cast event. For an upstream event, the names of the methods are identical to the upstream event names, as introduced in the ChannelEvent documentation. For a downstream event, the names of the methods starts with the name of the operation and ends with "Requested" (e.g. writeRequested.)

Please use SimpleChannelUpstreamHandler or SimpleChannelDownstreamHandler if you want to intercept only upstream or downstream events.

Overriding the handleUpstream and handleDownstream method

You can override the handleUpstream and handleDownstream method just like overriding an ordinary Java method. Please make sure to call super.handleUpstream() or super.handleDownstream() so that other handler methods are invoked properly:

public class MyChannelHandler extends SimpleChannelHandler {

     @Override
     public void handleUpstream(ChannelHandlerContext ctx, ChannelEvent e) throws Exception {

         // Log all channel state changes.
         if (e instanceof ChannelStateEvent) {
             logger.info("Channel state changed: " + e);
         }

         super.handleUpstream(ctx, e);
     }

     @Override
     public void handleDownstream(ChannelHandlerContext ctx, ChannelEvent e) throws Exception {

         // Log all channel state changes.
         if (e instanceof MessageEvent) {
             logger.info("Writing:: " + e);
         }

         super.handleDownstream(ctx, e);
     }
 }

Version:

$Rev: 2122 $, $Date: 2010-02-02 11:00:04 +0900 (Tue, 02 Feb 2010) $

Author:

The Netty Project, Trustin Lee

Nested Class Summary

Nested classes/interfaces inherited from interface org.jboss.netty.channel.ChannelHandler

ChannelHandler.Sharable

Constructor Summary

SimpleChannelHandler()
Creates a new instance.

Method Summary

void	bindRequested(ChannelHandlerContext ctx, ChannelStateEvent e) Invoked when Channel.bind(SocketAddress) was called.
void	channelBound(ChannelHandlerContext ctx, ChannelStateEvent e) Invoked when a Channel is open and bound to a local address, but not connected.
void	channelClosed(ChannelHandlerContext ctx, ChannelStateEvent e) Invoked when a Channel was closed and all its related resources were released.
void	channelConnected(ChannelHandlerContext ctx, ChannelStateEvent e) Invoked when a Channel is open, bound to a local address, and connected to a remote address.
void	channelDisconnected(ChannelHandlerContext ctx, ChannelStateEvent e) Invoked when a Channel was disconnected from its remote peer.
void	channelInterestChanged(ChannelHandlerContext ctx, ChannelStateEvent e) Invoked when a Channel's interestOps was changed.
void	channelOpen(ChannelHandlerContext ctx, ChannelStateEvent e) Invoked when a Channel is open, but not bound nor connected.
void	channelUnbound(ChannelHandlerContext ctx, ChannelStateEvent e) Invoked when a Channel was unbound from the current local address.
void	childChannelClosed(ChannelHandlerContext ctx, ChildChannelStateEvent e) Invoked when a child Channel was closed.
void	childChannelOpen(ChannelHandlerContext ctx, ChildChannelStateEvent e) Invoked when a child Channel was open.
void	closeRequested(ChannelHandlerContext ctx, ChannelStateEvent e) Invoked when Channel.close() was called.
void	connectRequested(ChannelHandlerContext ctx, ChannelStateEvent e) Invoked when Channel.connect(SocketAddress) was called.
void	disconnectRequested(ChannelHandlerContext ctx, ChannelStateEvent e) Invoked when Channel.disconnect() was called.
void	exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) Invoked when an exception was raised by an I/O thread or a ChannelHandler.
void	handleDownstream(ChannelHandlerContext ctx, ChannelEvent e) Handles the specified downstream event.
void	handleUpstream(ChannelHandlerContext ctx, ChannelEvent e) Handles the specified upstream event.
void	messageReceived(ChannelHandlerContext ctx, MessageEvent e) Invoked when a message object (e.g: ChannelBuffer) was received from a remote peer.
void	setInterestOpsRequested(ChannelHandlerContext ctx, ChannelStateEvent e) Invoked when Channel.setInterestOps(int) was called.
void	unbindRequested(ChannelHandlerContext ctx, ChannelStateEvent e) Invoked when Channel.unbind() was called.
void	writeComplete(ChannelHandlerContext ctx, WriteCompletionEvent e) Invoked when something was written into a Channel.
void	writeRequested(ChannelHandlerContext ctx, MessageEvent e) Invoked when Channel.write(Object) is called.

Methods inherited from class java.lang.Object

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

Constructor Detail

SimpleChannelHandler

public SimpleChannelHandler()

Creates a new instance.

Method Detail

handleUpstream

public void handleUpstream(ChannelHandlerContext ctx,
                           ChannelEvent e)
                    throws Exception

Handles the specified upstream event. Down-casts the received upstream event into more meaningful sub-type event and calls an appropriate handler method with the down-casted event.

Specified by:

handleUpstream in interface ChannelUpstreamHandler

Parameters:

ctx - the context object for this handler

e - the upstream event to process or intercept

Throws:

Exception

messageReceived

public void messageReceived(ChannelHandlerContext ctx,
                            MessageEvent e)
                     throws Exception

Invoked when a message object (e.g: ChannelBuffer) was received from a remote peer.

Throws:

Exception

exceptionCaught

public void exceptionCaught(ChannelHandlerContext ctx,
                            ExceptionEvent e)
                     throws Exception

Invoked when an exception was raised by an I/O thread or a ChannelHandler.

Throws:

Exception

channelOpen

public void channelOpen(ChannelHandlerContext ctx,
                        ChannelStateEvent e)
                 throws Exception

Invoked when a Channel is open, but not bound nor connected.

Throws:

Exception

channelBound

public void channelBound(ChannelHandlerContext ctx,
                         ChannelStateEvent e)
                  throws Exception

Invoked when a Channel is open and bound to a local address, but not connected.

Throws:

Exception

channelConnected

public void channelConnected(ChannelHandlerContext ctx,
                             ChannelStateEvent e)
                      throws Exception

Invoked when a Channel is open, bound to a local address, and connected to a remote address.

Throws:

Exception

channelInterestChanged

public void channelInterestChanged(ChannelHandlerContext ctx,
                                   ChannelStateEvent e)
                            throws Exception

Invoked when a Channel's interestOps was changed.

Throws:

Exception

channelDisconnected

public void channelDisconnected(ChannelHandlerContext ctx,
                                ChannelStateEvent e)
                         throws Exception

Invoked when a Channel was disconnected from its remote peer.

Throws:

Exception

channelUnbound

public void channelUnbound(ChannelHandlerContext ctx,
                           ChannelStateEvent e)
                    throws Exception

Invoked when a Channel was unbound from the current local address.

Throws:

Exception

channelClosed

public void channelClosed(ChannelHandlerContext ctx,
                          ChannelStateEvent e)
                   throws Exception

Invoked when a Channel was closed and all its related resources were released.

Throws:

Exception

writeComplete

public void writeComplete(ChannelHandlerContext ctx,
                          WriteCompletionEvent e)
                   throws Exception

Invoked when something was written into a Channel.

Throws:

Exception

childChannelOpen

public void childChannelOpen(ChannelHandlerContext ctx,
                             ChildChannelStateEvent e)
                      throws Exception

Invoked when a child Channel was open. (e.g. a server channel accepted a connection)

Throws:

Exception

childChannelClosed

public void childChannelClosed(ChannelHandlerContext ctx,
                               ChildChannelStateEvent e)
                        throws Exception

Invoked when a child Channel was closed. (e.g. the accepted connection was closed)

Throws:

Exception

handleDownstream

public void handleDownstream(ChannelHandlerContext ctx,
                             ChannelEvent e)
                      throws Exception

Handles the specified downstream event. Down-casts the received downstream event into more meaningful sub-type event and calls an appropriate handler method with the down-casted event.

Specified by:

handleDownstream in interface ChannelDownstreamHandler

Parameters:

ctx - the context object for this handler

e - the downstream event to process or intercept

Throws:

Exception

writeRequested

public void writeRequested(ChannelHandlerContext ctx,
                           MessageEvent e)
                    throws Exception

Invoked when Channel.write(Object) is called.

Throws:

Exception

bindRequested

public void bindRequested(ChannelHandlerContext ctx,
                          ChannelStateEvent e)
                   throws Exception

Invoked when Channel.bind(SocketAddress) was called.

Throws:

Exception

connectRequested

public void connectRequested(ChannelHandlerContext ctx,
                             ChannelStateEvent e)
                      throws Exception

Invoked when Channel.connect(SocketAddress) was called.

Throws:

Exception

setInterestOpsRequested

public void setInterestOpsRequested(ChannelHandlerContext ctx,
                                    ChannelStateEvent e)
                             throws Exception

Invoked when Channel.setInterestOps(int) was called.

Throws:

Exception

disconnectRequested

public void disconnectRequested(ChannelHandlerContext ctx,
                                ChannelStateEvent e)
                         throws Exception

Invoked when Channel.disconnect() was called.

Throws:

Exception

unbindRequested

public void unbindRequested(ChannelHandlerContext ctx,
                            ChannelStateEvent e)
                     throws Exception

Invoked when Channel.unbind() was called.

Throws:

Exception

closeRequested

public void closeRequested(ChannelHandlerContext ctx,
                           ChannelStateEvent e)
                    throws Exception

Invoked when Channel.close() was called.

Throws:

Exception