/*
* Copyright 2011 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;
import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.logging.InternalLogger;
import org.jboss.netty.logging.InternalLoggerFactory;
/**
* A {@link 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 {@link ChannelEvent} documentation. For a
* downstream 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}.)
* <p>
* Please use {@link SimpleChannelUpstreamHandler} or
* {@link SimpleChannelDownstreamHandler} if you want to intercept only
* upstream or downstream events.
*
* <h3>Overriding the {@link #handleUpstream(ChannelHandlerContext, ChannelEvent) handleUpstream}
* and {@link #handleDownstream(ChannelHandlerContext, ChannelEvent) handleDownstream} method</h3>
* <p>
* You can override the {@link #handleUpstream(ChannelHandlerContext, ChannelEvent) handleUpstream}
* and {@link #handleDownstream(ChannelHandlerContext, ChannelEvent) handleDownstream}
* method just like overriding an ordinary Java method. Please make sure to
* call {@code super.handleUpstream()} or {@code super.handleDownstream()} so
* that other handler methods are invoked properly:
* </p>
* <pre>public class MyChannelHandler extends {@link SimpleChannelHandler} {
*
* {@code @Override}
* public void handleUpstream({@link ChannelHandlerContext} ctx, {@link ChannelEvent} e) throws Exception {
*
* // Log all channel state changes.
* if (e instanceof {@link ChannelStateEvent}) {
* logger.info("Channel state changed: " + e);
* }
*
* <strong>super.handleUpstream(ctx, e);</strong>
* }
*
* {@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);
* }
*
* <strong>super.handleDownstream(ctx, e);</strong>
* }
* }</pre>
*/
public class SimpleChannelHandler implements ChannelUpstreamHandler, ChannelDownstreamHandler {
private static final InternalLogger logger =
InternalLoggerFactory.getInstance(SimpleChannelHandler.class.getName());
/**
* Creates a new instance.
*/
public SimpleChannelHandler() {
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.sendUpstream(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);
}
/**
* {@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);
}
}