Java tutorial
/* * Copyright 2016 LINE Corporation * * LINE Corporation 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.linecorp.armeria.client.http; import static java.util.Objects.requireNonNull; import java.net.InetSocketAddress; import java.net.SocketAddress; import java.util.Collections; import java.util.EnumMap; import java.util.Map; import java.util.concurrent.ScheduledFuture; import java.util.concurrent.TimeUnit; import java.util.function.Function; import com.linecorp.armeria.client.SessionOptions; import com.linecorp.armeria.client.SessionProtocolNegotiationCache; import com.linecorp.armeria.client.SessionProtocolNegotiationException; import com.linecorp.armeria.client.pool.PoolKey; import com.linecorp.armeria.common.SessionProtocol; import io.netty.bootstrap.Bootstrap; import io.netty.channel.Channel; import io.netty.channel.ChannelFuture; import io.netty.channel.ChannelInitializer; import io.netty.channel.EventLoop; import io.netty.util.concurrent.Future; import io.netty.util.concurrent.Promise; class HttpSessionChannelFactory implements Function<PoolKey, Future<Channel>> { private final Bootstrap baseBootstrap; private final EventLoop eventLoop; private final Map<SessionProtocol, Bootstrap> bootstrapMap; private final SessionOptions options; HttpSessionChannelFactory(Bootstrap bootstrap, SessionOptions options) { baseBootstrap = requireNonNull(bootstrap); eventLoop = (EventLoop) bootstrap.config().group(); bootstrapMap = Collections.synchronizedMap(new EnumMap<>(SessionProtocol.class)); this.options = options; } @Override public Future<Channel> apply(PoolKey key) { final InetSocketAddress remoteAddress = key.remoteAddress(); final SessionProtocol protocol = key.sessionProtocol(); if (SessionProtocolNegotiationCache.isUnsupported(remoteAddress, protocol)) { // Fail immediately if it is sure that the remote address does not support the requested protocol. return eventLoop.newFailedFuture( new SessionProtocolNegotiationException(protocol, "previously failed negotiation")); } final Promise<Channel> sessionPromise = eventLoop.newPromise(); connect(remoteAddress, protocol, sessionPromise); return sessionPromise; } void connect(SocketAddress remoteAddress, SessionProtocol protocol, Promise<Channel> sessionPromise) { final Bootstrap bootstrap = bootstrap(protocol); final ChannelFuture connectFuture = bootstrap.connect(remoteAddress); connectFuture.addListener((ChannelFuture future) -> { if (future.isSuccess()) { initSession(protocol, future, sessionPromise); } else { sessionPromise.setFailure(future.cause()); } }); } private Bootstrap bootstrap(SessionProtocol sessionProtocol) { return bootstrapMap.computeIfAbsent(sessionProtocol, sp -> { Bootstrap bs = baseBootstrap.clone(); bs.handler(new ChannelInitializer<Channel>() { @Override protected void initChannel(Channel ch) throws Exception { ch.pipeline().addLast(new HttpClientPipelineConfigurator(sp, options)); } }); return bs; }); } private void initSession(SessionProtocol protocol, ChannelFuture connectFuture, Promise<Channel> sessionPromise) { assert connectFuture.isSuccess(); final Channel ch = connectFuture.channel(); final EventLoop eventLoop = ch.eventLoop(); assert eventLoop.inEventLoop(); final ScheduledFuture<?> timeoutFuture = eventLoop.schedule(() -> { if (sessionPromise.tryFailure(new SessionProtocolNegotiationException(protocol, "connection established, but session creation timed out: " + ch))) { ch.close(); } }, options.connectTimeoutMillis(), TimeUnit.MILLISECONDS); ch.pipeline().addLast(new HttpSessionHandler(this, ch, sessionPromise, timeoutFuture)); } }