org.springframework.http.server.reactive.AbstractServerHttpResponse Maven / Gradle / Ivy
/*
* Copyright 2002-2022 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.server.reactive;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicReference;
import java.util.function.Supplier;
import org.reactivestreams.Publisher;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.core.io.buffer.DataBufferFactory;
import org.springframework.core.io.buffer.DataBufferUtils;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatusCode;
import org.springframework.http.ResponseCookie;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.CollectionUtils;
import org.springframework.util.LinkedMultiValueMap;
import org.springframework.util.MultiValueMap;
/**
* Base class for {@link ServerHttpResponse} implementations.
*
* @author Rossen Stoyanchev
* @author Juergen Hoeller
* @author Sebastien Deleuze
* @author Brian Clozel
* @since 5.0
*/
public abstract class AbstractServerHttpResponse implements ServerHttpResponse {
/**
* COMMITTING -> COMMITTED is the period after doCommit is called but before
* the response status and headers have been applied to the underlying
* response during which time pre-commit actions can still make changes to
* the response status and headers.
*/
private enum State {NEW, COMMITTING, COMMIT_ACTION_FAILED, COMMITTED}
private final DataBufferFactory dataBufferFactory;
@Nullable
private HttpStatusCode statusCode;
private final HttpHeaders headers;
private final MultiValueMap cookies;
private final AtomicReference state = new AtomicReference<>(State.NEW);
private final List>> commitActions = new ArrayList<>(4);
@Nullable
private HttpHeaders readOnlyHeaders;
public AbstractServerHttpResponse(DataBufferFactory dataBufferFactory) {
this(dataBufferFactory, new HttpHeaders());
}
public AbstractServerHttpResponse(DataBufferFactory dataBufferFactory, HttpHeaders headers) {
Assert.notNull(dataBufferFactory, "DataBufferFactory must not be null");
Assert.notNull(headers, "HttpHeaders must not be null");
this.dataBufferFactory = dataBufferFactory;
this.headers = headers;
this.cookies = new LinkedMultiValueMap<>();
}
@Override
public final DataBufferFactory bufferFactory() {
return this.dataBufferFactory;
}
@Override
public boolean setStatusCode(@Nullable HttpStatusCode status) {
if (this.state.get() == State.COMMITTED) {
return false;
}
else {
this.statusCode = status;
return true;
}
}
@Override
@Nullable
public HttpStatusCode getStatusCode() {
return this.statusCode;
}
@Override
public boolean setRawStatusCode(@Nullable Integer statusCode) {
return setStatusCode(statusCode != null ? HttpStatusCode.valueOf(statusCode) : null);
}
@Override
@Nullable
@Deprecated
public Integer getRawStatusCode() {
return this.statusCode != null ? this.statusCode.value() : null;
}
@Override
public HttpHeaders getHeaders() {
if (this.readOnlyHeaders != null) {
return this.readOnlyHeaders;
}
else if (this.state.get() == State.COMMITTED) {
this.readOnlyHeaders = HttpHeaders.readOnlyHttpHeaders(this.headers);
return this.readOnlyHeaders;
}
else {
return this.headers;
}
}
@Override
public MultiValueMap getCookies() {
return (this.state.get() == State.COMMITTED ?
CollectionUtils.unmodifiableMultiValueMap(this.cookies) : this.cookies);
}
@Override
public void addCookie(ResponseCookie cookie) {
Assert.notNull(cookie, "ResponseCookie must not be null");
if (this.state.get() == State.COMMITTED) {
throw new IllegalStateException("Can't add the cookie " + cookie +
"because the HTTP response has already been committed");
}
else {
getCookies().add(cookie.getName(), cookie);
}
}
/**
* Return the underlying server response.
* Note: This is exposed mainly for internal framework
* use such as WebSocket upgrades in the spring-webflux module.
*/
public abstract T getNativeResponse();
@Override
public void beforeCommit(Supplier> action) {
this.commitActions.add(action);
}
@Override
public boolean isCommitted() {
State state = this.state.get();
return (state != State.NEW && state != State.COMMIT_ACTION_FAILED);
}
@Override
@SuppressWarnings("unchecked")
public final Mono writeWith(Publisher body) {
// For Mono we can avoid ChannelSendOperator and Reactor Netty is more optimized for Mono.
// We must resolve value first however, for a chance to handle potential error.
if (body instanceof Mono) {
return ((Mono) body)
.flatMap(buffer -> {
touchDataBuffer(buffer);
AtomicBoolean subscribed = new AtomicBoolean();
return doCommit(
() -> {
try {
return writeWithInternal(Mono.fromCallable(() -> buffer)
.doOnSubscribe(s -> subscribed.set(true))
.doOnDiscard(DataBuffer.class, DataBufferUtils::release));
}
catch (Throwable ex) {
return Mono.error(ex);
}
})
.doOnError(ex -> DataBufferUtils.release(buffer))
.doOnCancel(() -> {
if (!subscribed.get()) {
DataBufferUtils.release(buffer);
}
});
})
.doOnError(t -> getHeaders().clearContentHeaders())
.doOnDiscard(DataBuffer.class, DataBufferUtils::release);
}
else {
return new ChannelSendOperator<>(body, inner -> doCommit(() -> writeWithInternal(inner)))
.doOnError(t -> getHeaders().clearContentHeaders());
}
}
@Override
public final Mono writeAndFlushWith(Publisher> body) {
return new ChannelSendOperator<>(body, inner -> doCommit(() -> writeAndFlushWithInternal(inner)))
.doOnError(t -> getHeaders().clearContentHeaders());
}
@Override
public Mono setComplete() {
return !isCommitted() ? doCommit(null) : Mono.empty();
}
/**
* A variant of {@link #doCommit(Supplier)} for a response without a body.
* @return a completion publisher
*/
protected Mono doCommit() {
return doCommit(null);
}
/**
* Apply {@link #beforeCommit(Supplier) beforeCommit} actions, apply the
* response status and headers/cookies, and write the response body.
* @param writeAction the action to write the response body (may be {@code null})
* @return a completion publisher
*/
protected Mono doCommit(@Nullable Supplier> writeAction) {
Flux allActions = Flux.empty();
if (this.state.compareAndSet(State.NEW, State.COMMITTING)) {
if (!this.commitActions.isEmpty()) {
allActions = Flux.concat(Flux.fromIterable(this.commitActions).map(Supplier::get))
.doOnError(ex -> {
if (this.state.compareAndSet(State.COMMITTING, State.COMMIT_ACTION_FAILED)) {
getHeaders().clearContentHeaders();
}
});
}
}
else if (this.state.compareAndSet(State.COMMIT_ACTION_FAILED, State.COMMITTING)) {
// Skip commit actions
}
else {
return Mono.empty();
}
allActions = allActions.concatWith(Mono.fromRunnable(() -> {
applyStatusCode();
applyHeaders();
applyCookies();
this.state.set(State.COMMITTED);
}));
if (writeAction != null) {
allActions = allActions.concatWith(writeAction.get());
}
return allActions.then();
}
/**
* Write to the underlying the response.
* @param body the publisher to write with
*/
protected abstract Mono writeWithInternal(Publisher body);
/**
* Write to the underlying the response, and flush after each {@code Publisher}.
* @param body the publisher to write and flush with
*/
protected abstract Mono writeAndFlushWithInternal(Publisher> body);
/**
* Write the status code to the underlying response.
* This method is called once only.
*/
protected abstract void applyStatusCode();
/**
* Invoked when the response is getting committed allowing subclasses to
* make apply header values to the underlying response.
* Note that most subclasses use an {@link HttpHeaders} instance that
* wraps an adapter to the native response headers such that changes are
* propagated to the underlying response on the go. That means this callback
* is typically not used other than for specialized updates such as setting
* the contentType or characterEncoding fields in a Servlet response.
*/
protected abstract void applyHeaders();
/**
* Add cookies from {@link #getHeaders()} to the underlying response.
* This method is called once only.
*/
protected abstract void applyCookies();
/**
* Allow subclasses to associate a hint with the data buffer if it is a
* pooled buffer and supports leak tracking.
* @param buffer the buffer to attach a hint to
* @since 5.3.2
*/
protected void touchDataBuffer(DataBuffer buffer) {
}
}