org.jboss.netty.channel.SimpleChannelDownstreamHandler Maven / Gradle / Ivy
/*
* Copyright 2012 The Netty Project
*
* The Netty Project licenses this file to you under the Apache License,
* version 2.0 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/
package org.jboss.netty.channel;
import java.net.SocketAddress;
/**
* A {@link ChannelDownstreamHandler} which provides an individual handler
* method for each event type. This handler down-casts the received downstream
* event into more meaningful sub-type event and calls an appropriate handler
* method with the down-cast event. The names of the methods starts with the
* name of the operation and ends with {@code "Requested"}
* (e.g. {@link #writeRequested(ChannelHandlerContext, MessageEvent) writeRequested}.)
*
* Please use {@link SimpleChannelHandler} if you need to implement both
* {@link ChannelUpstreamHandler} and {@link ChannelDownstreamHandler}.
*
*
Overriding the {@link #handleDownstream(ChannelHandlerContext, ChannelEvent) handleDownstream} method
*
* You can override the {@link #handleDownstream(ChannelHandlerContext, ChannelEvent) handleDownstream}
* method just like overriding an ordinary Java method. Please make sure to
* call {@code super.handleDownstream()} so that other handler methods are
* invoked properly:
*
* public class MyChannelHandler extends {@link SimpleChannelDownstreamHandler} {
*
* {@code @Override}
* public void handleDownstream({@link ChannelHandlerContext} ctx, {@link ChannelEvent} e) throws Exception {
*
* // Log all channel state changes.
* if (e instanceof {@link MessageEvent}) {
* logger.info("Writing:: " + e);
* }
*
* super.handleDownstream(ctx, e);
* }
* }
*
* Caution:
*
* Use the *Later(..) methods of the {@link Channels} class if you want to send an upstream event
* from a {@link ChannelDownstreamHandler} otherwise you may run into threading issues.
*
*/
public class SimpleChannelDownstreamHandler implements ChannelDownstreamHandler {
/**
* {@inheritDoc} Down-casts the received downstream event into more
* meaningful sub-type event and calls an appropriate handler method with
* the down-casted event.
*/
public void handleDownstream(ChannelHandlerContext ctx, ChannelEvent e)
throws Exception {
if (e instanceof MessageEvent) {
writeRequested(ctx, (MessageEvent) e);
} else if (e instanceof ChannelStateEvent) {
ChannelStateEvent evt = (ChannelStateEvent) e;
switch (evt.getState()) {
case OPEN:
if (!Boolean.TRUE.equals(evt.getValue())) {
closeRequested(ctx, evt);
}
break;
case BOUND:
if (evt.getValue() != null) {
bindRequested(ctx, evt);
} else {
unbindRequested(ctx, evt);
}
break;
case CONNECTED:
if (evt.getValue() != null) {
connectRequested(ctx, evt);
} else {
disconnectRequested(ctx, evt);
}
break;
case INTEREST_OPS:
setInterestOpsRequested(ctx, evt);
break;
default:
ctx.sendDownstream(e);
}
} else {
ctx.sendDownstream(e);
}
}
/**
* Invoked when {@link Channel#write(Object)} is called.
*/
public void writeRequested(ChannelHandlerContext ctx, MessageEvent e) throws Exception {
ctx.sendDownstream(e);
}
/**
* Invoked when {@link Channel#bind(SocketAddress)} was called.
*/
public void bindRequested(ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
ctx.sendDownstream(e);
}
/**
* Invoked when {@link Channel#connect(SocketAddress)} was called.
*/
public void connectRequested(ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
ctx.sendDownstream(e);
}
/**
* Invoked when {@link Channel#setInterestOps(int)} was called.
*/
public void setInterestOpsRequested(ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
ctx.sendDownstream(e);
}
/**
* Invoked when {@link Channel#disconnect()} was called.
*/
public void disconnectRequested(ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
ctx.sendDownstream(e);
}
/**
* Invoked when {@link Channel#unbind()} was called.
*/
public void unbindRequested(ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
ctx.sendDownstream(e);
}
/**
* Invoked when {@link Channel#close()} was called.
*/
public void closeRequested(ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
ctx.sendDownstream(e);
}
}