io.netty.bootstrap.Bootstrap 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:
*
* https://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 io.netty.bootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.ChannelPromise;
import io.netty.channel.EventLoop;
import io.netty.channel.EventLoopGroup;
import io.netty.resolver.AddressResolver;
import io.netty.resolver.DefaultAddressResolverGroup;
import io.netty.resolver.NameResolver;
import io.netty.resolver.AddressResolverGroup;
import io.netty.util.concurrent.Future;
import io.netty.util.concurrent.FutureListener;
import io.netty.util.internal.ObjectUtil;
import io.netty.util.internal.logging.InternalLogger;
import io.netty.util.internal.logging.InternalLoggerFactory;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
/**
* A {@link Bootstrap} that makes it easy to bootstrap a {@link Channel} to use
* for clients.
*
* The {@link #bind()} methods are useful in combination with connectionless transports such as datagram (UDP).
* For regular TCP connections, please use the provided {@link #connect()} methods.
*/
public class Bootstrap extends AbstractBootstrap {
private static final InternalLogger logger = InternalLoggerFactory.getInstance(Bootstrap.class);
private final BootstrapConfig config = new BootstrapConfig(this);
private ExternalAddressResolver externalResolver;
private volatile boolean disableResolver;
private volatile SocketAddress remoteAddress;
public Bootstrap() { }
private Bootstrap(Bootstrap bootstrap) {
super(bootstrap);
externalResolver = bootstrap.externalResolver;
disableResolver = bootstrap.disableResolver;
remoteAddress = bootstrap.remoteAddress;
}
/**
* Sets the {@link NameResolver} which will resolve the address of the unresolved named address.
*
* @param resolver the {@link NameResolver} for this {@code Bootstrap}; may be {@code null}, in which case a default
* resolver will be used
*
* @see io.netty.resolver.DefaultAddressResolverGroup
*/
@SuppressWarnings("unchecked")
public Bootstrap resolver(AddressResolverGroup resolver) {
this.externalResolver = resolver == null ? null : new ExternalAddressResolver(resolver);
disableResolver = false;
return this;
}
/**
* Disables address name resolution. Name resolution may be re-enabled with
* {@link Bootstrap#resolver(AddressResolverGroup)}
*/
public Bootstrap disableResolver() {
externalResolver = null;
disableResolver = true;
return this;
}
/**
* The {@link SocketAddress} to connect to once the {@link #connect()} method
* is called.
*/
public Bootstrap remoteAddress(SocketAddress remoteAddress) {
this.remoteAddress = remoteAddress;
return this;
}
/**
* @see #remoteAddress(SocketAddress)
*/
public Bootstrap remoteAddress(String inetHost, int inetPort) {
remoteAddress = InetSocketAddress.createUnresolved(inetHost, inetPort);
return this;
}
/**
* @see #remoteAddress(SocketAddress)
*/
public Bootstrap remoteAddress(InetAddress inetHost, int inetPort) {
remoteAddress = new InetSocketAddress(inetHost, inetPort);
return this;
}
/**
* Connect a {@link Channel} to the remote peer.
*/
public ChannelFuture connect() {
validate();
SocketAddress remoteAddress = this.remoteAddress;
if (remoteAddress == null) {
throw new IllegalStateException("remoteAddress not set");
}
return doResolveAndConnect(remoteAddress, config.localAddress());
}
/**
* Connect a {@link Channel} to the remote peer.
*/
public ChannelFuture connect(String inetHost, int inetPort) {
return connect(InetSocketAddress.createUnresolved(inetHost, inetPort));
}
/**
* Connect a {@link Channel} to the remote peer.
*/
public ChannelFuture connect(InetAddress inetHost, int inetPort) {
return connect(new InetSocketAddress(inetHost, inetPort));
}
/**
* Connect a {@link Channel} to the remote peer.
*/
public ChannelFuture connect(SocketAddress remoteAddress) {
ObjectUtil.checkNotNull(remoteAddress, "remoteAddress");
validate();
return doResolveAndConnect(remoteAddress, config.localAddress());
}
/**
* Connect a {@link Channel} to the remote peer.
*/
public ChannelFuture connect(SocketAddress remoteAddress, SocketAddress localAddress) {
ObjectUtil.checkNotNull(remoteAddress, "remoteAddress");
validate();
return doResolveAndConnect(remoteAddress, localAddress);
}
/**
* @see #connect()
*/
private ChannelFuture doResolveAndConnect(final SocketAddress remoteAddress, final SocketAddress localAddress) {
final ChannelFuture regFuture = initAndRegister();
final Channel channel = regFuture.channel();
if (regFuture.isDone()) {
if (!regFuture.isSuccess()) {
return regFuture;
}
return doResolveAndConnect0(channel, remoteAddress, localAddress, channel.newPromise());
} else {
// Registration future is almost always fulfilled already, but just in case it's not.
final PendingRegistrationPromise promise = new PendingRegistrationPromise(channel);
regFuture.addListener(new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture future) throws Exception {
// Directly obtain the cause and do a null check so we only need one volatile read in case of a
// failure.
Throwable cause = future.cause();
if (cause != null) {
// Registration on the EventLoop failed so fail the ChannelPromise directly to not cause an
// IllegalStateException once we try to access the EventLoop of the Channel.
promise.setFailure(cause);
} else {
// Registration was successful, so set the correct executor to use.
// See https://github.com/netty/netty/issues/2586
promise.registered();
doResolveAndConnect0(channel, remoteAddress, localAddress, promise);
}
}
});
return promise;
}
}
private ChannelFuture doResolveAndConnect0(final Channel channel, SocketAddress remoteAddress,
final SocketAddress localAddress, final ChannelPromise promise) {
try {
if (disableResolver) {
doConnect(remoteAddress, localAddress, promise);
return promise;
}
final EventLoop eventLoop = channel.eventLoop();
AddressResolver resolver;
try {
resolver = ExternalAddressResolver.getOrDefault(externalResolver).getResolver(eventLoop);
} catch (Throwable cause) {
channel.close();
return promise.setFailure(cause);
}
if (!resolver.isSupported(remoteAddress) || resolver.isResolved(remoteAddress)) {
// Resolver has no idea about what to do with the specified remote address or it's resolved already.
doConnect(remoteAddress, localAddress, promise);
return promise;
}
final Future resolveFuture = resolver.resolve(remoteAddress);
if (resolveFuture.isDone()) {
final Throwable resolveFailureCause = resolveFuture.cause();
if (resolveFailureCause != null) {
// Failed to resolve immediately
channel.close();
promise.setFailure(resolveFailureCause);
} else {
// Succeeded to resolve immediately; cached? (or did a blocking lookup)
doConnect(resolveFuture.getNow(), localAddress, promise);
}
return promise;
}
// Wait until the name resolution is finished.
resolveFuture.addListener(new FutureListener() {
@Override
public void operationComplete(Future future) throws Exception {
if (future.cause() != null) {
channel.close();
promise.setFailure(future.cause());
} else {
doConnect(future.getNow(), localAddress, promise);
}
}
});
} catch (Throwable cause) {
promise.tryFailure(cause);
}
return promise;
}
private static void doConnect(
final SocketAddress remoteAddress, final SocketAddress localAddress, final ChannelPromise connectPromise) {
// This method is invoked before channelRegistered() is triggered. Give user handlers a chance to set up
// the pipeline in its channelRegistered() implementation.
final Channel channel = connectPromise.channel();
channel.eventLoop().execute(new Runnable() {
@Override
public void run() {
if (localAddress == null) {
channel.connect(remoteAddress, connectPromise);
} else {
channel.connect(remoteAddress, localAddress, connectPromise);
}
connectPromise.addListener(ChannelFutureListener.CLOSE_ON_FAILURE);
}
});
}
@Override
void init(Channel channel) {
ChannelPipeline p = channel.pipeline();
p.addLast(config.handler());
setChannelOptions(channel, newOptionsArray(), logger);
setAttributes(channel, newAttributesArray());
}
@Override
public Bootstrap validate() {
super.validate();
if (config.handler() == null) {
throw new IllegalStateException("handler not set");
}
return this;
}
@Override
@SuppressWarnings("CloneDoesntCallSuperClone")
public Bootstrap clone() {
return new Bootstrap(this);
}
/**
* Returns a deep clone of this bootstrap which has the identical configuration except that it uses
* the given {@link EventLoopGroup}. This method is useful when making multiple {@link Channel}s with similar
* settings.
*/
public Bootstrap clone(EventLoopGroup group) {
Bootstrap bs = new Bootstrap(this);
bs.group = group;
return bs;
}
@Override
public final BootstrapConfig config() {
return config;
}
final SocketAddress remoteAddress() {
return remoteAddress;
}
final AddressResolverGroup resolver() {
if (disableResolver) {
return null;
}
return ExternalAddressResolver.getOrDefault(externalResolver);
}
/* Holder to avoid NoClassDefFoundError in case netty-resolver dependency is excluded
(e.g. some address families do not need name resolution) */
static final class ExternalAddressResolver {
final AddressResolverGroup resolverGroup;
@SuppressWarnings("unchecked")
ExternalAddressResolver(AddressResolverGroup resolverGroup) {
this.resolverGroup = (AddressResolverGroup) resolverGroup;
}
@SuppressWarnings("unchecked")
static AddressResolverGroup getOrDefault(ExternalAddressResolver externalResolver) {
if (externalResolver == null) {
AddressResolverGroup defaultResolverGroup = DefaultAddressResolverGroup.INSTANCE;
return (AddressResolverGroup) defaultResolverGroup;
}
return externalResolver.resolverGroup;
}
}
}
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