org.springframework.web.servlet.function.DefaultAsyncServerResponse 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.web.servlet.function;
import java.io.IOException;
import java.time.Duration;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.CompletionException;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.function.Function;
import jakarta.servlet.ServletException;
import jakarta.servlet.http.Cookie;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.reactivestreams.Publisher;
import org.springframework.core.ReactiveAdapter;
import org.springframework.core.ReactiveAdapterRegistry;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatusCode;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.util.MultiValueMap;
import org.springframework.web.context.request.async.AsyncWebRequest;
import org.springframework.web.context.request.async.DeferredResult;
import org.springframework.web.context.request.async.WebAsyncManager;
import org.springframework.web.context.request.async.WebAsyncUtils;
import org.springframework.web.servlet.ModelAndView;
/**
* Default {@link AsyncServerResponse} implementation.
*
* @author Arjen Poutsma
* @since 5.3.2
*/
final class DefaultAsyncServerResponse extends ErrorHandlingServerResponse implements AsyncServerResponse {
static final boolean reactiveStreamsPresent = ClassUtils.isPresent(
"org.reactivestreams.Publisher", DefaultAsyncServerResponse.class.getClassLoader());
private final CompletableFuture futureResponse;
@Nullable
private final Duration timeout;
private DefaultAsyncServerResponse(CompletableFuture futureResponse, @Nullable Duration timeout) {
this.futureResponse = futureResponse;
this.timeout = timeout;
}
@Override
public ServerResponse block() {
try {
if (this.timeout != null) {
return this.futureResponse.get(this.timeout.toMillis(), TimeUnit.MILLISECONDS);
}
else {
return this.futureResponse.get();
}
}
catch (InterruptedException | ExecutionException | TimeoutException ex) {
throw new IllegalStateException("Failed to get future response", ex);
}
}
@Override
public HttpStatusCode statusCode() {
return delegate(ServerResponse::statusCode);
}
@Override
@Deprecated
public int rawStatusCode() {
return delegate(ServerResponse::rawStatusCode);
}
@Override
public HttpHeaders headers() {
return delegate(ServerResponse::headers);
}
@Override
public MultiValueMap cookies() {
return delegate(ServerResponse::cookies);
}
private R delegate(Function function) {
ServerResponse response = this.futureResponse.getNow(null);
if (response != null) {
return function.apply(response);
}
else {
throw new IllegalStateException("Future ServerResponse has not yet completed");
}
}
@Nullable
@Override
public ModelAndView writeTo(HttpServletRequest request, HttpServletResponse response, Context context)
throws ServletException, IOException {
writeAsync(request, response, createDeferredResult(request));
return null;
}
static void writeAsync(HttpServletRequest request, HttpServletResponse response, DeferredResult deferredResult)
throws ServletException, IOException {
WebAsyncManager asyncManager = WebAsyncUtils.getAsyncManager(request);
AsyncWebRequest asyncWebRequest = WebAsyncUtils.createAsyncWebRequest(request, response);
asyncManager.setAsyncWebRequest(asyncWebRequest);
try {
asyncManager.startDeferredResultProcessing(deferredResult);
}
catch (IOException | ServletException ex) {
throw ex;
}
catch (Exception ex) {
throw new ServletException("Async processing failed", ex);
}
}
private DeferredResult createDeferredResult(HttpServletRequest request) {
DeferredResult result;
if (this.timeout != null) {
result = new DeferredResult<>(this.timeout.toMillis());
}
else {
result = new DeferredResult<>();
}
this.futureResponse.whenComplete((value, ex) -> {
if (ex != null) {
if (ex instanceof CompletionException && ex.getCause() != null) {
ex = ex.getCause();
}
ServerResponse errorResponse = errorResponse(ex, request);
if (errorResponse != null) {
result.setResult(errorResponse);
}
else {
result.setErrorResult(ex);
}
}
else {
result.setResult(value);
}
});
return result;
}
@SuppressWarnings({"unchecked", "rawtypes"})
public static AsyncServerResponse create(Object obj, @Nullable Duration timeout) {
Assert.notNull(obj, "Argument to async must not be null");
if (obj instanceof CompletableFuture futureResponse) {
return new DefaultAsyncServerResponse(futureResponse, timeout);
}
else if (reactiveStreamsPresent) {
ReactiveAdapterRegistry registry = ReactiveAdapterRegistry.getSharedInstance();
ReactiveAdapter publisherAdapter = registry.getAdapter(obj.getClass());
if (publisherAdapter != null) {
Publisher publisher = publisherAdapter.toPublisher(obj);
ReactiveAdapter futureAdapter = registry.getAdapter(CompletableFuture.class);
if (futureAdapter != null) {
CompletableFuture futureResponse =
(CompletableFuture) futureAdapter.fromPublisher(publisher);
return new DefaultAsyncServerResponse(futureResponse, timeout);
}
}
}
throw new IllegalArgumentException("Asynchronous type not supported: " + obj.getClass());
}
}