/*
* 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 com.facebook.presto.jdbc.internal.netty.bootstrap;
import com.facebook.presto.jdbc.internal.netty.channel.Channel;
import com.facebook.presto.jdbc.internal.netty.channel.ChannelConfig;
import com.facebook.presto.jdbc.internal.netty.channel.ChannelFactory;
import com.facebook.presto.jdbc.internal.netty.channel.ChannelFuture;
import com.facebook.presto.jdbc.internal.netty.channel.ChannelHandler;
import com.facebook.presto.jdbc.internal.netty.channel.ChannelPipeline;
import com.facebook.presto.jdbc.internal.netty.channel.ChannelPipelineException;
import com.facebook.presto.jdbc.internal.netty.channel.ChannelPipelineFactory;
import com.facebook.presto.jdbc.internal.netty.channel.Channels;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
/**
* A helper class which creates a new client-side {@link Channel} and makes a
* connection attempt.
*
* <h3>Configuring a channel</h3>
*
* {@link #setOption(String, Object) Options} are used to configure a channel:
*
* <pre>
* {@link ClientBootstrap} b = ...;
*
* // Options for a new channel
* b.setOption("remoteAddress", new {@link InetSocketAddress}("example.com", 8080));
* b.setOption("tcpNoDelay", true);
* b.setOption("receiveBufferSize", 1048576);
* </pre>
*
* For the detailed list of available options, please refer to
* {@link ChannelConfig} and its sub-types.
*
* <h3>Configuring a channel pipeline</h3>
*
* 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)}.
*
* <pre>
* {@link ClientBootstrap} 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;
* }
* }
* </pre>
* <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:
*
* <pre>
* {@link ClientBootstrap} 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());
* </pre>
*
* 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.
*
* <h3>Applying different settings for different {@link Channel}s</h3>
*
* {@link ClientBootstrap} 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 ClientBootstrap}. Therefore, it is OK to create as many
* {@link ClientBootstrap} instances as you want with the same
* {@link ChannelFactory} to apply different settings for different
* {@link Channel}s.
*
* @apiviz.landmark
*/
public class ClientBootstrap extends Bootstrap {
/**
* Creates a new instance with no {@link ChannelFactory} set.
* {@link #setFactory(ChannelFactory)} must be called before any I/O
* operation is requested.
*/
public ClientBootstrap() {
}
/**
* Creates a new instance with the specified initial {@link ChannelFactory}.
*/
public ClientBootstrap(ChannelFactory channelFactory) {
super(channelFactory);
}
/**
* Attempts a new connection with the current {@code "remoteAddress"} and
* {@code "localAddress"} option. If the {@code "localAddress"} option is
* not set, the local address of a new channel is determined automatically.
* This method is similar to the following code:
*
* <pre>
* {@link ClientBootstrap} b = ...;
* b.connect(b.getOption("remoteAddress"), b.getOption("localAddress"));
* </pre>
*
* @return a future object which notifies when this connection attempt
* succeeds or fails
*
* @throws IllegalStateException
* if {@code "remoteAddress"} option was not set
* @throws ClassCastException
* if {@code "remoteAddress"} or {@code "localAddress"} option's
* value is neither a {@link SocketAddress} nor {@code null}
* @throws ChannelPipelineException
* if this bootstrap's {@link #setPipelineFactory(ChannelPipelineFactory) pipelineFactory}
* failed to create a new {@link ChannelPipeline}
*/
public ChannelFuture connect() {
SocketAddress remoteAddress = (SocketAddress) getOption("remoteAddress");
if (remoteAddress == null) {
throw new IllegalStateException("remoteAddress option is not set.");
}
return connect(remoteAddress);
}
/**
* Attempts a new connection with the specified {@code remoteAddress} and
* the current {@code "localAddress"} option. If the {@code "localAddress"}
* option is not set, the local address of a new channel is determined
* automatically. This method is identical with the following code:
*
* <pre>
* {@link ClientBootstrap} b = ...;
* b.connect(remoteAddress, b.getOption("localAddress"));
* </pre>
*
* @return a future object which notifies when this connection attempt
* succeeds or fails
*
* @throws ClassCastException
* if {@code "localAddress"} option's value is
* neither a {@link SocketAddress} nor {@code null}
* @throws ChannelPipelineException
* if this bootstrap's {@link #setPipelineFactory(ChannelPipelineFactory) pipelineFactory}
* failed to create a new {@link ChannelPipeline}
*/
public ChannelFuture connect(SocketAddress remoteAddress) {
if (remoteAddress == null) {
throw new NullPointerException("remoteAddress");
}
SocketAddress localAddress = (SocketAddress) getOption("localAddress");
return connect(remoteAddress, localAddress);
}
/**
* Attempts a new connection with the specified {@code remoteAddress} and
* the specified {@code localAddress}. If the specified local address is
* {@code null}, the local address of a new channel is determined
* automatically.
*
* @return a future object which notifies when this connection attempt
* succeeds or fails
*
* @throws ChannelPipelineException
* if this bootstrap's {@link #setPipelineFactory(ChannelPipelineFactory) pipelineFactory}
* failed to create a new {@link ChannelPipeline}
*/
public ChannelFuture connect(final SocketAddress remoteAddress, final SocketAddress localAddress) {
if (remoteAddress == null) {
throw new NullPointerException("remoteAddress");
}
ChannelPipeline pipeline;
try {
pipeline = getPipelineFactory().getPipeline();
} catch (Exception e) {
throw new ChannelPipelineException("Failed to initialize a pipeline.", e);
}
// Set the options.
Channel ch = getFactory().newChannel(pipeline);
boolean success = false;
try {
ch.getConfig().setOptions(getOptions());
success = true;
} finally {
if (!success) {
ch.close();
}
}
// Bind.
if (localAddress != null) {
ch.bind(localAddress);
}
// Connect.
return ch.connect(remoteAddress);
}
/**
* Attempts to bind a channel with the specified {@code localAddress}. later the channel can
* be connected to a remoteAddress by calling {@link Channel#connect(SocketAddress)}.This method
* is useful where bind and connect need to be done in separate steps.
* <p>
* For an instance, a user can set an attachment to the {@link Channel} via
* {@link Channel#setAttachment(Object)} before beginning a connection attempt so that the user can access
* the attachment once the connection is established:
*
* <pre>
* ChannelFuture bindFuture = bootstrap.bind(new InetSocketAddress("192.168.0.15", 0));
* Channel channel = bindFuture.getChannel();
* channel.setAttachment(dataObj);
* channel.connect(new InetSocketAddress("192.168.0.30", 8080));
* </pre>
*
* The attachment can be accessed then in the handler like the following:
*
* <pre>
* public class YourHandler extends SimpleChannelUpstreamHandler {
* public void channelConnected(ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
* Object dataObject = ctx.getChannel().getAttachment();
* }
* }
*
* </pre>
*
* @return a future object which notifies when this bind attempt
* succeeds or fails
*
* @throws ChannelPipelineException
* if this bootstrap's {@link #setPipelineFactory(ChannelPipelineFactory) pipelineFactory}
* failed to create a new {@link ChannelPipeline}
*/
public ChannelFuture bind(final SocketAddress localAddress) {
if (localAddress == null) {
throw new NullPointerException("localAddress");
}
ChannelPipeline pipeline;
try {
pipeline = getPipelineFactory().getPipeline();
} catch (Exception e) {
throw new ChannelPipelineException("Failed to initialize a pipeline.", e);
}
// Set the options.
Channel ch = getFactory().newChannel(pipeline);
boolean success = false;
try {
ch.getConfig().setOptions(getOptions());
success = true;
} finally {
if (!success) {
ch.close();
}
}
// Bind.
return ch.bind(localAddress);
}
}