/*
* Copyright 2002-2016 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
*
* 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 org.springframework.http.server.reactive;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.function.Supplier;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.reactivestreams.Publisher;
import reactor.core.publisher.Mono;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.core.io.buffer.DataBufferFactory;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseCookie;
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 Sebastien Deleuze
*/
public abstract class AbstractServerHttpResponse implements ServerHttpResponse {
private Log logger = LogFactory.getLog(getClass());
private static final int STATE_NEW = 1;
private static final int STATE_COMMITTING = 2;
private static final int STATE_COMMITTED = 3;
private final DataBufferFactory dataBufferFactory;
private HttpStatus statusCode;
private final HttpHeaders headers;
private final MultiValueMap<String, ResponseCookie> cookies;
private final List<Supplier<? extends Mono<Void>>> beforeCommitActions = new ArrayList<>(4);
private final AtomicInteger state = new AtomicInteger(STATE_NEW);
public AbstractServerHttpResponse(DataBufferFactory dataBufferFactory) {
Assert.notNull(dataBufferFactory, "'dataBufferFactory' must not be null");
this.dataBufferFactory = dataBufferFactory;
this.headers = new HttpHeaders();
this.cookies = new LinkedMultiValueMap<String, ResponseCookie>();
}
@Override
public final DataBufferFactory bufferFactory() {
return this.dataBufferFactory;
}
@Override
public boolean setStatusCode(HttpStatus statusCode) {
Assert.notNull(statusCode);
if (STATE_NEW == this.state.get()) {
this.statusCode = statusCode;
return true;
}
else if (logger.isDebugEnabled()) {
logger.debug("Can't set the status " + statusCode.toString() +
" because the HTTP response has already been committed");
}
return false;
}
@Override
public HttpStatus getStatusCode() {
return this.statusCode;
}
@Override
public HttpHeaders getHeaders() {
if (STATE_COMMITTED == this.state.get()) {
return HttpHeaders.readOnlyHttpHeaders(this.headers);
}
else {
return this.headers;
}
}
@Override
public MultiValueMap<String, ResponseCookie> getCookies() {
if (STATE_COMMITTED == this.state.get()) {
return CollectionUtils.unmodifiableMultiValueMap(this.cookies);
}
return this.cookies;
}
@Override
public void beforeCommit(Supplier<? extends Mono<Void>> action) {
Assert.notNull(action);
this.beforeCommitActions.add(action);
}
@Override
public Mono<Void> writeWith(Publisher<DataBuffer> publisher) {
return new ChannelSendOperator<>(publisher, writePublisher ->
applyBeforeCommit().then(() -> writeWithInternal(writePublisher)));
}
protected Mono<Void> applyBeforeCommit() {
Mono<Void> mono = Mono.empty();
if (this.state.compareAndSet(STATE_NEW, STATE_COMMITTING)) {
for (Supplier<? extends Mono<Void>> action : this.beforeCommitActions) {
mono = mono.then(action);
}
mono = mono.otherwise(ex -> {
// Ignore errors from beforeCommit actions
return Mono.empty();
});
mono = mono.then(() -> {
this.state.set(STATE_COMMITTED);
writeStatusCode();
writeHeaders();
writeCookies();
return Mono.empty();
});
}
return mono;
}
/**
* Implement this method to write to the underlying the response.
* @param body the publisher to write with
*/
protected abstract Mono<Void> writeWithInternal(Publisher<DataBuffer> body);
/**
* Implement this method to write the status code to the underlying response.
* This method is called once only.
*/
protected abstract void writeStatusCode();
/**
* Implement this method to apply header changes from {@link #getHeaders()}
* to the underlying response. This method is called once only.
*/
protected abstract void writeHeaders();
/**
* Implement this method to add cookies from {@link #getHeaders()} to the
* underlying response. This method is called once only.
*/
protected abstract void writeCookies();
@Override
public Mono<Void> setComplete() {
return applyBeforeCommit();
}
}