* Please use {@link SimpleChannelHandler} if you need to implement both * {@link ChannelUpstreamHandler} and {@link ChannelDownstreamHandler}. * *
* You can override the {@link #handleUpstream(ChannelHandlerContext, ChannelEvent) handleUpstream} * method just like overriding an ordinary Java method. Please make sure to * call {@code super.handleUpstream()} so that other handler methods are invoked * properly: *
*public class MyChannelHandler extends SimpleChannelUpstreamHandler {
*
* public void handleUpstream({@link ChannelHandlerContext} ctx, {@link ChannelEvent} e) throws Exception {
*
* // Log all channel state changes.
* if (e instanceof ChannelStateEvent) {
* logger.info("Channel state changed: " + e);
* }
*
* super.handleUpstream(ctx, e);
* }
* }
*
* @author The Netty Project (netty-dev@lists.jboss.org)
* @author Trustin Lee (tlee@redhat.com)
*
* @version $Rev$, $Date$
*/
public class SimpleChannelUpstreamHandler implements ChannelUpstreamHandler {
private static final InternalLogger logger =
InternalLoggerFactory.getInstance(SimpleChannelUpstreamHandler.class.getName());
/**
* Creates a new instance.
*/
public SimpleChannelUpstreamHandler() {
super();
}
/**
* {@inheritDoc} Down-casts the received upstream event into more
* meaningful sub-type event and calls an appropriate handler method with
* the down-casted event.
*/
public void handleUpstream(
ChannelHandlerContext ctx, ChannelEvent e) throws Exception {
if (e instanceof MessageEvent) {
messageReceived(ctx, (MessageEvent) e);
} else if (e instanceof WriteCompletionEvent) {
WriteCompletionEvent evt = (WriteCompletionEvent) e;
writeComplete(ctx, evt);
} else if (e instanceof ChildChannelStateEvent) {
ChildChannelStateEvent evt = (ChildChannelStateEvent) e;
if (evt.getChildChannel().isOpen()) {
childChannelOpen(ctx, evt);
} else {
childChannelClosed(ctx, evt);
}
} else if (e instanceof ChannelStateEvent) {
ChannelStateEvent evt = (ChannelStateEvent) e;
switch (evt.getState()) {
case OPEN:
if (Boolean.TRUE.equals(evt.getValue())) {
channelOpen(ctx, evt);
} else {
channelClosed(ctx, evt);
}
break;
case BOUND:
if (evt.getValue() != null) {
channelBound(ctx, evt);
} else {
channelUnbound(ctx, evt);
}
break;
case CONNECTED:
if (evt.getValue() != null) {
channelConnected(ctx, evt);
} else {
channelDisconnected(ctx, evt);
}
break;
case INTEREST_OPS:
channelInterestChanged(ctx, evt);
break;
default:
ctx.sendDownstream(e);
}
} else if (e instanceof ExceptionEvent) {
exceptionCaught(ctx, (ExceptionEvent) e);
} else {
ctx.sendUpstream(e);
}
}
/**
* Invoked when a message object (e.g: {@link ChannelBuffer}) was received
* from a remote peer.
*/
public void messageReceived(
ChannelHandlerContext ctx, MessageEvent e) throws Exception {
ctx.sendUpstream(e);
}
/**
* Invoked when an exception was raised by an I/O thread or a
* {@link ChannelHandler}.
*/
public void exceptionCaught(
ChannelHandlerContext ctx, ExceptionEvent e) throws Exception {
if (this == ctx.getPipeline().getLast()) {
logger.warn(
"EXCEPTION, please implement " + getClass().getName() +
".exceptionCaught() for proper handling.", e.getCause());
}
ctx.sendUpstream(e);
}
/**
* Invoked when a {@link Channel} is open, but not bound nor connected.
*/
public void channelOpen(
ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
ctx.sendUpstream(e);
}
/**
* Invoked when a {@link Channel} is open and bound to a local address,
* but not connected.
*/
public void channelBound(
ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
ctx.sendUpstream(e);
}
/**
* Invoked when a {@link Channel} is open, bound to a local address, and
* connected to a remote address.
*/
public void channelConnected(
ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
ctx.sendUpstream(e);
}
/**
* Invoked when a {@link Channel}'s {@link Channel#getInterestOps() interestOps}
* was changed.
*/
public void channelInterestChanged(
ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
ctx.sendUpstream(e);
}
/**
* Invoked when a {@link Channel} was disconnected from its remote peer.
*/
public void channelDisconnected(
ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
ctx.sendUpstream(e);
}
/**
* Invoked when a {@link Channel} was unbound from the current local address.
*/
public void channelUnbound(
ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
ctx.sendUpstream(e);
}
/**
* Invoked when a {@link Channel} was closed and all its related resources
* were released.
*/
public void channelClosed(
ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
ctx.sendUpstream(e);
}
/**
* Invoked when something was written into a {@link Channel}.
*/
public void writeComplete(
ChannelHandlerContext ctx, WriteCompletionEvent e) throws Exception {
ctx.sendUpstream(e);
}
/**
* Invoked when a child {@link Channel} was open.
* (e.g. a server channel accepted a connection)
*/
public void childChannelOpen(
ChannelHandlerContext ctx, ChildChannelStateEvent e) throws Exception {
ctx.sendUpstream(e);
}
/**
* Invoked when a child {@link Channel} was closed.
* (e.g. the accepted connection was closed)
*/
public void childChannelClosed(
ChannelHandlerContext ctx, ChildChannelStateEvent e) throws Exception {
ctx.sendUpstream(e);
}
}