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/* * Copyright 2002-2019 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.AtomicReference; import java.util.function.Supplier; import org.apache.commons.logging.Log; 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.core.io.buffer.PooledDataBuffer; import org.springframework.http.HttpHeaders; import org.springframework.http.HttpLogging; import org.springframework.http.HttpStatus; 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, COMMITTED } protected final Log logger = HttpLogging.forLogName(getClass()); private final DataBufferFactory dataBufferFactory; @Nullable private Integer statusCode; private final HttpHeaders headers; private final MultiValueMap<String, ResponseCookie> cookies; private final AtomicReference<State> state = new AtomicReference<>(State.NEW); private final List<Supplier<? extends Mono<Void>>> commitActions = new ArrayList<>(4); 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 HttpStatus status) { if (this.state.get() == State.COMMITTED) { return false; } else { this.statusCode = (status != null ? status.value() : null); return true; } } @Override @Nullable public HttpStatus getStatusCode() { return (this.statusCode != null ? HttpStatus.resolve(this.statusCode) : null); } /** * Set the HTTP status code of the response. * @param statusCode the HTTP status as an integer value * @since 5.0.1 */ public void setStatusCodeValue(@Nullable Integer statusCode) { this.statusCode = statusCode; } /** * Return the HTTP status code of the response. * @return the HTTP status as an integer value * @since 5.0.1 */ @Nullable public Integer getStatusCodeValue() { return this.statusCode; } @Override public HttpHeaders getHeaders() { return (this.state.get() == State.COMMITTED ? HttpHeaders.readOnlyHttpHeaders(this.headers) : this.headers); } @Override public MultiValueMap<String, ResponseCookie> 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. * <p><strong>Note:</strong> This is exposed mainly for internal framework * use such as WebSocket upgrades in the spring-webflux module. */ public abstract <T> T getNativeResponse(); @Override public void beforeCommit(Supplier<? extends Mono<Void>> action) { this.commitActions.add(action); } @Override public boolean isCommitted() { return this.state.get() != State.NEW; } @Override @SuppressWarnings("unchecked") public final Mono<Void> writeWith(Publisher<? extends DataBuffer> body) { // Write as Mono if possible as an optimization hint to Reactor Netty // ChannelSendOperator not necessary for Mono if (body instanceof Mono) { return ((Mono<? extends DataBuffer>) body) .flatMap(buffer -> doCommit(() -> writeWithInternal(Mono.just(buffer))) .doOnDiscard(PooledDataBuffer.class, DataBufferUtils::release)); } return new ChannelSendOperator<>(body, inner -> doCommit(() -> writeWithInternal(inner))) .doOnError(t -> removeContentLength()); } @Override public final Mono<Void> writeAndFlushWith(Publisher<? extends Publisher<? extends DataBuffer>> body) { return new ChannelSendOperator<>(body, inner -> doCommit(() -> writeAndFlushWithInternal(inner))) .doOnError(t -> removeContentLength()); } private void removeContentLength() { if (!this.isCommitted()) { this.getHeaders().remove(HttpHeaders.CONTENT_LENGTH); } } @Override public Mono<Void> setComplete() { return !isCommitted() ? doCommit(null) : Mono.empty(); } /** * A variant of {@link #doCommit(Supplier)} for a response without no body. * @return a completion publisher */ protected Mono<Void> 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<Void> doCommit(@Nullable Supplier<? extends Mono<Void>> writeAction) { if (!this.state.compareAndSet(State.NEW, State.COMMITTING)) { return Mono.empty(); } this.commitActions.add(() -> Mono.fromRunnable(() -> { applyStatusCode(); applyHeaders(); applyCookies(); this.state.set(State.COMMITTED); })); if (writeAction != null) { this.commitActions.add(writeAction); } Flux<Void> commit = Flux.empty(); for (Supplier<? extends Mono<Void>> action : this.commitActions) { commit = commit.concatWith(action.get()); } return commit.then(); } /** * Write to the underlying the response. * @param body the publisher to write with */ protected abstract Mono<Void> writeWithInternal(Publisher<? extends DataBuffer> body); /** * Write to the underlying the response, and flush after each {@code Publisher<DataBuffer>}. * @param body the publisher to write and flush with */ protected abstract Mono<Void> writeAndFlushWithInternal( Publisher<? extends Publisher<? extends DataBuffer>> body); /** * Write the status code to the underlying response. * This method is called once only. */ protected abstract void applyStatusCode(); /** * Apply header changes from {@link #getHeaders()} to the underlying response. * This method is called once only. */ protected abstract void applyHeaders(); /** * Add cookies from {@link #getHeaders()} to the underlying response. * This method is called once only. */ protected abstract void applyCookies(); }