org.jboss.netty.bootstrap.ServerBootstrap Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of netty Show documentation
Show all versions of netty Show documentation
The Netty project is an effort to provide an asynchronous event-driven
network application framework and tools for rapid development of
maintainable high performance and high scalability protocol servers and
clients. In other words, Netty is a NIO client server framework which
enables quick and easy development of network applications such as protocol
servers and clients. It greatly simplifies and streamlines network
programming such as TCP and UDP socket server.
/*
* 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.bootstrap;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelConfig;
import org.jboss.netty.channel.ChannelException;
import org.jboss.netty.channel.ChannelFactory;
import org.jboss.netty.channel.ChannelFuture;
import org.jboss.netty.channel.ChannelFutureListener;
import org.jboss.netty.channel.ChannelHandler;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.ChannelPipeline;
import org.jboss.netty.channel.ChannelPipelineFactory;
import org.jboss.netty.channel.ChannelStateEvent;
import org.jboss.netty.channel.Channels;
import org.jboss.netty.channel.ChildChannelStateEvent;
import org.jboss.netty.channel.DefaultChannelFuture;
import org.jboss.netty.channel.ExceptionEvent;
import org.jboss.netty.channel.ServerChannelFactory;
import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import static org.jboss.netty.channel.Channels.*;
/**
* A helper class which creates a new server-side {@link Channel} and accepts
* incoming connections.
*
* Only for connection oriented transports
*
* This bootstrap is for connection oriented transports only such as TCP/IP
* and local transport. Use {@link ConnectionlessBootstrap} instead for
* connectionless transports. Do not use this helper if you are using a
* connectionless transport such as UDP/IP which does not accept an incoming
* connection but receives messages by itself without creating a child channel.
*
* Parent channel and its children
*
* A parent channel is a channel which is supposed to accept incoming
* connections. It is created by this bootstrap's {@link ChannelFactory} via
* {@link #bind()} and {@link #bind(SocketAddress)}.
*
* Once successfully bound, the parent channel starts to accept incoming
* connections, and the accepted connections become the children of the
* parent channel.
*
*
Configuring channels
*
* {@link #setOption(String, Object) Options} are used to configure both a
* parent channel and its child channels. To configure the child channels,
* prepend {@code "child."} prefix to the actual option names of a child
* channel:
*
*
* {@link ServerBootstrap} b = ...;
*
* // Options for a parent channel
* b.setOption("localAddress", new {@link InetSocketAddress}(8080));
* b.setOption("reuseAddress", true);
*
* // Options for its children
* b.setOption("child.tcpNoDelay", true);
* b.setOption("child.receiveBufferSize", 1048576);
*
*
* For the detailed list of available options, please refer to
* {@link ChannelConfig} and its sub-types.
*
* Configuring a parent channel pipeline
*
* It is rare to customize the pipeline of a parent channel because what it is
* supposed to do is very typical. However, you might want to add a handler
* to deal with some special needs such as degrading the process
* UID from
* a superuser to a
* normal user and changing the current VM security manager for better
* security. To support such a case,
* the {@link #setParentHandler(ChannelHandler) parentHandler} property is
* provided.
*
* Configuring a child channel pipeline
*
* Every channel has its own {@link ChannelPipeline} and you can configure it
* in two ways.
*
* The recommended approach is to specify a {@link ChannelPipelineFactory} by
* calling {@link #setPipelineFactory(ChannelPipelineFactory)}.
*
*
* {@link ServerBootstrap} b = ...;
* b.setPipelineFactory(new MyPipelineFactory());
*
* public class MyPipelineFactory implements {@link ChannelPipelineFactory} {
* public {@link ChannelPipeline} getPipeline() throws Exception {
* // Create and configure a new pipeline for a new channel.
* {@link ChannelPipeline} p = {@link Channels}.pipeline();
* p.addLast("encoder", new EncodingHandler());
* p.addLast("decoder", new DecodingHandler());
* p.addLast("logic", new LogicHandler());
* return p;
* }
* }
*
*
* The alternative approach, which works only in a certain situation, is to use
* the default pipeline and let the bootstrap to shallow-copy the default
* pipeline for each new channel:
*
*
* {@link ServerBootstrap} b = ...;
* {@link ChannelPipeline} p = b.getPipeline();
*
* // Add handlers to the default pipeline.
* p.addLast("encoder", new EncodingHandler());
* p.addLast("decoder", new DecodingHandler());
* p.addLast("logic", new LogicHandler());
*
*
* Please note 'shallow-copy' here means that the added {@link ChannelHandler}s
* are not cloned but only their references are added to the new pipeline.
* Therefore, you cannot use this approach if you are going to open more than
* one {@link Channel}s or run a server that accepts incoming connections to
* create its child channels.
*
* Applying different settings for different {@link Channel}s
*
* {@link ServerBootstrap} is just a helper class. It neither allocates nor
* manages any resources. What manages the resources is the
* {@link ChannelFactory} implementation you specified in the constructor of
* {@link ServerBootstrap}. Therefore, it is OK to create as many
* {@link ServerBootstrap} instances as you want with the same
* {@link ChannelFactory} to apply different settings for different
* {@link Channel}s.
*
* @apiviz.landmark
*/
public class ServerBootstrap extends Bootstrap {
private volatile ChannelHandler parentHandler;
/**
* Creates a new instance with no {@link ChannelFactory} set.
* {@link #setFactory(ChannelFactory)} must be called before any I/O
* operation is requested.
*/
public ServerBootstrap() {
}
/**
* Creates a new instance with the specified initial {@link ChannelFactory}.
*/
public ServerBootstrap(ChannelFactory channelFactory) {
super(channelFactory);
}
/**
* Sets the {@link ServerChannelFactory} that will be used to perform an I/O
* operation. This method can be called only once and can't be called at
* all if the factory was specified in the constructor.
*
* @throws IllegalStateException
* if the factory is already set
* @throws IllegalArgumentException
* if the specified {@code factory} is not a
* {@link ServerChannelFactory}
*/
@Override
public void setFactory(ChannelFactory factory) {
if (factory == null) {
throw new NullPointerException("factory");
}
if (!(factory instanceof ServerChannelFactory)) {
throw new IllegalArgumentException(
"factory must be a " +
ServerChannelFactory.class.getSimpleName() + ": " +
factory.getClass());
}
super.setFactory(factory);
}
/**
* Returns an optional {@link ChannelHandler} which intercepts an event
* of a newly bound server-side channel which accepts incoming connections.
*
* @return the parent channel handler.
* {@code null} if no parent channel handler is set.
*/
public ChannelHandler getParentHandler() {
return parentHandler;
}
/**
* Sets an optional {@link ChannelHandler} which intercepts an event of
* a newly bound server-side channel which accepts incoming connections.
*
* @param parentHandler
* the parent channel handler.
* {@code null} to unset the current parent channel handler.
*/
public void setParentHandler(ChannelHandler parentHandler) {
this.parentHandler = parentHandler;
}
/**
* Creates a new channel which is bound to the local address which was
* specified in the current {@code "localAddress"} option. This method is
* similar to the following code:
*
*
* {@link ServerBootstrap} b = ...;
* b.bind(b.getOption("localAddress"));
*
*
* This operation will block until the channel is bound.
*
* @return a new bound channel which accepts incoming connections
*
* @throws IllegalStateException
* if {@code "localAddress"} option was not set
* @throws ClassCastException
* if {@code "localAddress"} option's value is
* neither a {@link SocketAddress} nor {@code null}
* @throws ChannelException
* if failed to create a new channel and
* bind it to the local address
*/
public Channel bind() {
SocketAddress localAddress = (SocketAddress) getOption("localAddress");
if (localAddress == null) {
throw new IllegalStateException("localAddress option is not set.");
}
return bind(localAddress);
}
/**
* Creates a new channel which is bound to the specified local address. This operation will block until
* the channel is bound.
*
* @return a new bound channel which accepts incoming connections
*
* @throws ChannelException
* if failed to create a new channel and
* bind it to the local address
*/
public Channel bind(final SocketAddress localAddress) {
ChannelFuture future = bindAsync(localAddress);
// Wait for the future.
future.awaitUninterruptibly();
if (!future.isSuccess()) {
future.getChannel().close().awaitUninterruptibly();
throw new ChannelException("Failed to bind to: " + localAddress, future.getCause());
}
return future.getChannel();
}
/**
* Bind a channel asynchronous to the local address
* specified in the current {@code "localAddress"} option. This method is
* similar to the following code:
*
*
* {@link ServerBootstrap} b = ...;
* b.bindAsync(b.getOption("localAddress"));
*
*
*
* @return a new {@link ChannelFuture} which will be notified once the Channel is
* bound and accepts incoming connections
*
* @throws IllegalStateException
* if {@code "localAddress"} option was not set
* @throws ClassCastException
* if {@code "localAddress"} option's value is
* neither a {@link SocketAddress} nor {@code null}
* @throws ChannelException
* if failed to create a new channel and
* bind it to the local address
*/
public ChannelFuture bindAsync() {
SocketAddress localAddress = (SocketAddress) getOption("localAddress");
if (localAddress == null) {
throw new IllegalStateException("localAddress option is not set.");
}
return bindAsync(localAddress);
}
/**
* Bind a channel asynchronous to the specified local address.
*
* @return a new {@link ChannelFuture} which will be notified once the Channel is
* bound and accepts incoming connections
*
*/
public ChannelFuture bindAsync(final SocketAddress localAddress) {
if (localAddress == null) {
throw new NullPointerException("localAddress");
}
Binder binder = new Binder(localAddress);
ChannelHandler parentHandler = getParentHandler();
ChannelPipeline bossPipeline = pipeline();
bossPipeline.addLast("binder", binder);
if (parentHandler != null) {
bossPipeline.addLast("userHandler", parentHandler);
}
Channel channel = getFactory().newChannel(bossPipeline);
final ChannelFuture bfuture = new DefaultChannelFuture(channel, false);
binder.bindFuture.addListener(new ChannelFutureListener() {
public void operationComplete(ChannelFuture future) throws Exception {
if (future.isSuccess()) {
bfuture.setSuccess();
} else {
// Call close on bind failure
bfuture.getChannel().close();
bfuture.setFailure(future.getCause());
}
}
});
return bfuture;
}
private final class Binder extends SimpleChannelUpstreamHandler {
private final SocketAddress localAddress;
private final Map childOptions =
new HashMap();
private final DefaultChannelFuture bindFuture = new DefaultChannelFuture(null, false);
Binder(SocketAddress localAddress) {
this.localAddress = localAddress;
}
@Override
public void channelOpen(
ChannelHandlerContext ctx,
ChannelStateEvent evt) {
try {
evt.getChannel().getConfig().setPipelineFactory(getPipelineFactory());
// Split options into two categories: parent and child.
Map allOptions = getOptions();
Map parentOptions = new HashMap();
for (Entry e: allOptions.entrySet()) {
if (e.getKey().startsWith("child.")) {
childOptions.put(
e.getKey().substring(6),
e.getValue());
} else if (!"pipelineFactory".equals(e.getKey())) {
parentOptions.put(e.getKey(), e.getValue());
}
}
// Apply parent options.
evt.getChannel().getConfig().setOptions(parentOptions);
} finally {
ctx.sendUpstream(evt);
}
evt.getChannel().bind(localAddress).addListener(new ChannelFutureListener() {
public void operationComplete(ChannelFuture future) throws Exception {
if (future.isSuccess()) {
bindFuture.setSuccess();
} else {
bindFuture.setFailure(future.getCause());
}
}
});
}
@Override
public void childChannelOpen(
ChannelHandlerContext ctx,
ChildChannelStateEvent e) throws Exception {
// Apply child options.
try {
e.getChildChannel().getConfig().setOptions(childOptions);
} catch (Throwable t) {
fireExceptionCaught(e.getChildChannel(), t);
}
ctx.sendUpstream(e);
}
@Override
public void exceptionCaught(
ChannelHandlerContext ctx, ExceptionEvent e)
throws Exception {
bindFuture.setFailure(e.getCause());
ctx.sendUpstream(e);
}
}
}