org.springframework.http.client.reactive.ReactorClientHttpConnector Maven / Gradle / Ivy
/*
* Copyright 2002-2023 the original author or authors.
*
* Licensed 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 org.springframework.http.client.reactive;
import java.net.URI;
import java.util.concurrent.atomic.AtomicReference;
import java.util.function.Function;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import reactor.core.publisher.Mono;
import reactor.netty.NettyOutbound;
import reactor.netty.http.client.HttpClient;
import reactor.netty.http.client.HttpClientRequest;
import reactor.netty.resources.ConnectionProvider;
import reactor.netty.resources.LoopResources;
import org.springframework.context.SmartLifecycle;
import org.springframework.http.HttpMethod;
import org.springframework.http.client.ReactorResourceFactory;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
/**
* Reactor-Netty implementation of {@link ClientHttpConnector}.
*
* This class implements {@link SmartLifecycle} and can be optionally declared
* as a Spring-managed bean.
*
* @author Brian Clozel
* @author Rossen Stoyanchev
* @author Sebastien Deleuze
* @since 5.0
* @see reactor.netty.http.client.HttpClient
*/
public class ReactorClientHttpConnector implements ClientHttpConnector, SmartLifecycle {
private static final Log logger = LogFactory.getLog(ReactorClientHttpConnector.class);
private static final Function defaultInitializer = client -> client.compress(true);
private HttpClient httpClient;
@Nullable
private final ReactorResourceFactory resourceFactory;
@Nullable
private final Function mapper;
private volatile boolean running = true;
private final Object lifecycleMonitor = new Object();
/**
* Default constructor. Initializes {@link HttpClient} via:
*
* HttpClient.create().compress()
*
*/
public ReactorClientHttpConnector() {
this.httpClient = defaultInitializer.apply(HttpClient.create());
this.resourceFactory = null;
this.mapper = null;
}
/**
* Constructor with externally managed Reactor Netty resources, including
* {@link LoopResources} for event loop threads, and {@link ConnectionProvider}
* for the connection pool.
* This constructor should be used only when you don't want the client
* to participate in the Reactor Netty global resources. By default the
* client participates in the Reactor Netty global resources held in
* {@link reactor.netty.http.HttpResources}, which is recommended since
* fixed, shared resources are favored for event loop concurrency. However,
* consider declaring a {@link ReactorResourceFactory} bean with
* {@code globalResources=true} in order to ensure the Reactor Netty global
* resources are shut down when the Spring ApplicationContext is stopped or closed
* and restarted properly when the Spring ApplicationContext is
* (with JVM Checkpoint Restore for example).
* @param resourceFactory the resource factory to obtain the resources from
* @param mapper a mapper for further initialization of the created client
* @since 5.1
*/
public ReactorClientHttpConnector(ReactorResourceFactory resourceFactory, Function mapper) {
this.httpClient = createHttpClient(resourceFactory, mapper);
this.resourceFactory = resourceFactory;
this.mapper = mapper;
}
private static HttpClient createHttpClient(ReactorResourceFactory resourceFactory, Function mapper) {
ConnectionProvider provider = resourceFactory.getConnectionProvider();
Assert.notNull(provider, "No ConnectionProvider: is ReactorResourceFactory not initialized yet?");
return defaultInitializer.andThen(mapper).andThen(applyLoopResources(resourceFactory))
.apply(HttpClient.create(provider));
}
private static Function applyLoopResources(ReactorResourceFactory factory) {
return httpClient -> {
LoopResources resources = factory.getLoopResources();
Assert.notNull(resources, "No LoopResources: is ReactorResourceFactory not initialized yet?");
return httpClient.runOn(resources);
};
}
/**
* Constructor with a pre-configured {@code HttpClient} instance.
* @param httpClient the client to use
* @since 5.1
*/
public ReactorClientHttpConnector(HttpClient httpClient) {
Assert.notNull(httpClient, "HttpClient is required");
this.httpClient = httpClient;
this.resourceFactory = null;
this.mapper = null;
}
@Override
public Mono connect(HttpMethod method, URI uri,
Function> requestCallback) {
AtomicReference responseRef = new AtomicReference<>();
HttpClient.RequestSender requestSender = this.httpClient
.request(io.netty.handler.codec.http.HttpMethod.valueOf(method.name()));
requestSender = setUri(requestSender, uri);
return requestSender
.send((request, outbound) -> requestCallback.apply(adaptRequest(method, uri, request, outbound)))
.responseConnection((response, connection) -> {
responseRef.set(new ReactorClientHttpResponse(response, connection));
return Mono.just((ClientHttpResponse) responseRef.get());
})
.next()
.doOnCancel(() -> {
ReactorClientHttpResponse response = responseRef.get();
if (response != null) {
response.releaseAfterCancel(method);
}
});
}
private static HttpClient.RequestSender setUri(HttpClient.RequestSender requestSender, URI uri) {
if (uri.isAbsolute()) {
try {
return requestSender.uri(uri);
}
catch (Exception ex) {
// Fall back on passing it in as a String
}
}
return requestSender.uri(uri.toString());
}
private ReactorClientHttpRequest adaptRequest(HttpMethod method, URI uri, HttpClientRequest request,
NettyOutbound nettyOutbound) {
return new ReactorClientHttpRequest(method, uri, request, nettyOutbound);
}
@Override
public void start() {
synchronized (this.lifecycleMonitor) {
if (!isRunning()) {
if (this.resourceFactory != null && this.mapper != null) {
this.httpClient = createHttpClient(this.resourceFactory, this.mapper);
}
else {
logger.warn("Restarting a ReactorClientHttpConnector bean is only supported with externally managed Reactor Netty resources");
}
this.running = true;
}
}
}
@Override
public void stop() {
synchronized (this.lifecycleMonitor) {
if (isRunning()) {
this.running = false;
}
}
}
@Override
public final void stop(Runnable callback) {
synchronized (this.lifecycleMonitor) {
stop();
callback.run();
}
}
@Override
public boolean isRunning() {
return this.running;
}
@Override
public boolean isAutoStartup() {
return false;
}
@Override
public int getPhase() {
// Start after ReactorResourceFactory
return 1;
}
}