/*
* Copyright (c) 2015, 2018, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package java.net.http;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import java.nio.channels.FileChannel;
import java.nio.charset.StandardCharsets;
import java.nio.file.OpenOption;
import java.nio.file.Path;
import java.nio.file.StandardOpenOption;
import java.util.List;
import java.util.Objects;
import java.util.Optional;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.CompletionStage;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.Flow;
import java.util.concurrent.Flow.Subscriber;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.stream.Stream;
import javax.net.ssl.SSLParameters;
import jdk.internal.net.http.BufferingSubscriber;
import jdk.internal.net.http.LineSubscriberAdapter;
import jdk.internal.net.http.ResponseBodyHandlers.FileDownloadBodyHandler;
import jdk.internal.net.http.ResponseBodyHandlers.PathBodyHandler;
import jdk.internal.net.http.ResponseBodyHandlers.PushPromisesHandlerWithMap;
import jdk.internal.net.http.ResponseSubscribers;
import static jdk.internal.net.http.common.Utils.charsetFrom;
/**
* An HTTP response.
*
* <p> An {@code HttpResponse} is not created directly, but rather returned as
* a result of sending an {@link HttpRequest}. An {@code HttpResponse} is
* made available when the response status code and headers have been received,
* and typically after the response body has also been completely received.
* Whether or not the {@code HttpResponse} is made available before the response
* body has been completely received depends on the {@link BodyHandler
* BodyHandler} provided when sending the {@code HttpRequest}.
*
* <p> This class provides methods for accessing the response status code,
* headers, the response body, and the {@code HttpRequest} corresponding
* to this response.
**
* @param <T> the response body type
*
* @since 11
*/
public abstract class HttpResponse<T> {
/**
* Creates an HttpResponse.
*/
protected HttpResponse() { }
/**
* Returns the status code for this response.
*
* @return the response code
*/
public abstract int statusCode();
/**
* Returns the {@link HttpRequest} corresponding to this response.
*
* <p> This may not be the original request provided by the caller,
* for example, if that request was redirected.
*
* @see #previousResponse()
*
* @return the request
*/
public abstract HttpRequest request();
/**
* Returns an {@code Optional} containing the previous intermediate response
* if one was received. An intermediate response is one that is received
* as a result of redirection or authentication. If no previous response
* was received then an empty {@code Optional} is returned.
*
* @return an Optional containing the HttpResponse, if any.
*/
public abstract Optional<HttpResponse<T>> previousResponse();
/**
* Returns the received response headers.
*
* @return the response headers
*/
public abstract HttpHeaders headers();
/**
* Returns the body. Depending on the type of {@code T}, the returned body
* may represent the body after it was read (such as {@code byte[]}, or
* {@code String}, or {@code Path}) or it may represent an object with
* which the body is read, such as an {@link java.io.InputStream}.
*
* <p> If this {@code HttpResponse} was returned from an invocation of
* {@link #previousResponse()} then this method returns {@code null}
*
* @return the body
*/
public abstract T body();
/**
* Returns the {@link javax.net.ssl.SSLParameters} in effect for this
* response. Returns {@code null} if this is not a HTTPS response.
*
* @return the SSLParameters associated with the response
*/
public abstract SSLParameters sslParameters();
/**
* Returns the {@code URI} that the response was received from. This may be
* different from the request {@code URI} if redirection occurred.
*
* @return the URI of the response
*/
public abstract URI uri();
/**
* Returns the HTTP protocol version that was used for this response.
*
* @return HTTP protocol version
*/
public abstract HttpClient.Version version();
private static String pathForSecurityCheck(Path path) {
return path.toFile().getPath();
}
/**
* A handler for response bodies.
*
* <p> The {@code BodyHandler} interface allows inspection of the response
* code and headers, before the actual response body is received, and is
* responsible for creating the response {@link BodySubscriber
* BodySubscriber}. The {@code BodySubscriber} consumes the actual response
* body bytes and converts them into a higher-level Java type.
*
* <p> A {@code BodyHandler} is a function that takes two parameters: the
* response status code and the response headers; and which returns a
* {@code BodySubscriber}. The {@code BodyHandler} is invoked when the
* response status code and headers are available, but before the response
* body bytes are received.
*
* <p> A number of convenience static factory methods are provided that
* return pre-defined implementations that do not examine the status code
* (meaning the body is always accepted):
* <ul><li>{@link #asByteArray() }</li>
* <li>{@link #asByteArrayConsumer(java.util.function.Consumer)
* asByteArrayConsumer(Consumer)}</li>
* <li>{@link #asString(java.nio.charset.Charset) asString(Charset)}</li>
* <li>{@link #asFile(Path, OpenOption...) asFile(Path,OpenOption...)}</li>
* <li>{@link #asFileDownload(java.nio.file.Path,OpenOption...)
* asFileDownload(Path,OpenOption...)}</li>
* <li>{@link #asInputStream() asInputStream()}</li>
* <li>{@link #discard() }</li>
* <li>{@link #replace(Object) }</li>
* <li>{@link #buffering(BodyHandler, int) buffering(BodyHandler,int)}</li>
* </ul>
*
* <p> These implementations return an equivalently named {@code
* BodySubscriber}. Alternatively, a custom handler can be used to examine
* the status code or headers, and return different body subscribers as
* appropriate.
*
* <p><b>Examples:</b>
*
* <p> The first example uses one of the predefined handler functions that
* always process the response body in the same way.
* <pre>{@code HttpRequest request = HttpRequest.newBuilder()
* .uri(URI.create("http://www.foo.com/"))
* .build();
* client.sendAsync(request, BodyHandler.asFile(Paths.get("/tmp/f")))
* .thenApply(HttpResponse::body)
* .thenAccept(System.out::println) }</pre>
* Note, that even though these pre-defined handlers do not examine the
* response code, the response code and headers are always retrievable from
* the {@link HttpResponse}, when it is returned.
*
* <p> In the second example, the function returns a different subscriber
* depending on the status code.
* <pre>{@code HttpRequest request = HttpRequest.newBuilder()
* .uri(URI.create("http://www.foo.com/"))
* .build();
* BodyHandler bodyHandler = (status, headers) -> status == 200
* ? BodySubscriber.asFile(Paths.get("/tmp/f"))
* : BodySubscriber.replace(Paths.get("/NULL")));
* client.sendAsync(request, bodyHandler))
* .thenApply(HttpResponse::body)
* .thenAccept(System.out::println) }</pre>
*
* @param <T> the response body type
*/
@FunctionalInterface
public interface BodyHandler<T> {
/**
* Returns a {@link BodySubscriber BodySubscriber} considering the
* given response status code and headers. This method is invoked before
* the actual response body bytes are read and its implementation must
* return a {@code BodySubscriber} to consume the response body bytes.
*
* <p> The response body can be discarded using one of {@link
* #discard() discard} or {@link #replace(Object) replace}.
*
* @param statusCode the HTTP status code received
* @param responseHeaders the response headers received
* @return a body subscriber
*/
public BodySubscriber<T> apply(int statusCode, HttpHeaders responseHeaders);
/**
* Returns a response body handler that returns a {@link BodySubscriber
* BodySubscriber}{@code <Void>} obtained from {@link
* BodySubscriber#fromSubscriber(Subscriber)}, with the given
* {@code subscriber}.
*
* <p> The response body is not available through this, or the {@code
* HttpResponse} API, but instead all response body is forwarded to the
* given {@code subscriber}, which should make it available, if
* appropriate, through some other mechanism, e.g. an entry in a
* database, etc.
*
* @apiNote This method can be used as an adapter between {@code
* BodySubscriber} and {@code Flow.Subscriber}.
*
* <p> For example:
* <pre> {@code TextSubscriber subscriber = new TextSubscriber();
* HttpResponse<Void> response = client.sendAsync(request,
* BodyHandler.fromSubscriber(subscriber)).join();
* System.out.println(response.statusCode()); }</pre>
*
* @param subscriber the subscriber
* @return a response body handler
*/
public static BodyHandler<Void>
fromSubscriber(Subscriber<? super List<ByteBuffer>> subscriber) {
Objects.requireNonNull(subscriber);
return (status, headers) -> BodySubscriber.fromSubscriber(subscriber,
s -> null);
}
/**
* Returns a response body handler that returns a {@link BodySubscriber
* BodySubscriber}{@code <T>} obtained from {@link
* BodySubscriber#fromSubscriber(Subscriber, Function)}, with the
* given {@code subscriber} and {@code finisher} function.
*
* <p> The given {@code finisher} function is applied after the given
* subscriber's {@code onComplete} has been invoked. The {@code finisher}
* function is invoked with the given subscriber, and returns a value
* that is set as the response's body.
*
* @apiNote This method can be used as an adapter between {@code
* BodySubscriber} and {@code Flow.Subscriber}.
*
* <p> For example:
* <pre> {@code TextSubscriber subscriber = ...; // accumulates bytes and transforms them into a String
* HttpResponse<String> response = client.sendAsync(request,
* BodyHandler.fromSubscriber(subscriber, TextSubscriber::getTextResult)).join();
* String text = response.body(); }</pre>
*
* @param <S> the type of the Subscriber
* @param <T> the type of the response body
* @param subscriber the subscriber
* @param finisher a function to be applied after the subscriber has completed
* @return a response body handler
*/
public static <S extends Subscriber<? super List<ByteBuffer>>,T> BodyHandler<T>
fromSubscriber(S subscriber, Function<S,T> finisher) {
Objects.requireNonNull(subscriber);
Objects.requireNonNull(finisher);
return (status, headers) -> BodySubscriber.fromSubscriber(subscriber,
finisher);
}
/**
* Returns a response body handler that returns a {@link BodySubscriber
* BodySubscriber}{@code <Void>} obtained from {@link
* BodySubscriber#fromLineSubscriber(Subscriber, Function, Charset, String)
* BodySubscriber.fromLineSubscriber(subscriber, s -> null, charset, null)},
* with the given {@code subscriber}.
* The {@link Charset charset} used to decode the response body bytes is
* obtained from the HTTP response headers as specified by {@link #asString()},
* and lines are delimited in the manner of {@link BufferedReader#readLine()}.
*
* <p> The response body is not available through this, or the {@code
* HttpResponse} API, but instead all response body is forwarded to the
* given {@code subscriber}, which should make it available, if
* appropriate, through some other mechanism, e.g. an entry in a
* database, etc.
*
* @apiNote This method can be used as an adapter between {@code
* BodySubscriber} and {@code Flow.Subscriber}.
*
* <p> For example:
* <pre> {@code TextSubscriber subscriber = new TextSubscriber();
* HttpResponse<Void> response = client.sendAsync(request,
* BodyHandler.fromLineSubscriber(subscriber, "\n")).join();
* System.out.println(response.statusCode()); }</pre>
*
* @param subscriber the subscriber
* @return a response body handler
*/
public static BodyHandler<Void>
fromLineSubscriber(Subscriber<? super String> subscriber) {
Objects.requireNonNull(subscriber);
return (status, headers)
-> BodySubscriber.fromLineSubscriber(subscriber, s -> null,
charsetFrom(headers), null);
}
/**
* Returns a response body handler that returns a {@link BodySubscriber
* BodySubscriber}{@code <T>} obtained from {@link
* BodySubscriber#fromLineSubscriber(Subscriber, Function, Charset, String)
* BodySubscriber.fromLineSubscriber(subscriber, finisher, charset, lineSeparator)},
* with the given {@code subscriber}, {@code finisher} function, and line separator.
* The {@link Charset charset} used to decode the response body bytes is
* obtained from the HTTP response headers as specified by {@link #asString()}.
*
* <p> The given {@code finisher} function is applied after the given
* subscriber's {@code onComplete} has been invoked. The {@code finisher}
* function is invoked with the given subscriber, and returns a value
* that is set as the response's body.
*
* @apiNote This method can be used as an adapter between {@code
* BodySubscriber} and {@code Flow.Subscriber}.
*
* <p> For example:
* <pre> {@code TextSubscriber subscriber = ...; // accumulates bytes and transforms them into a String
* HttpResponse<String> response = client.sendAsync(request,
* BodyHandler.fromSubscriber(subscriber, TextSubscriber::getTextResult, "\n")).join();
* String text = response.body(); }</pre>
*
* @param <S> the type of the Subscriber
* @param <T> the type of the response body
* @param subscriber the subscriber
* @param finisher a function to be applied after the subscriber has completed
* @param lineSeparator an optional line separator: can be {@code null},
* in which case lines will be delimited in the manner of
* {@link BufferedReader#readLine()}.
* @return a response body handler
* @throws IllegalArgumentException if the supplied {@code lineSeparator} is the empty string.
*/
public static <S extends Subscriber<? super String>,T> BodyHandler<T>
fromLineSubscriber(S subscriber, Function<S,T> finisher, String lineSeparator) {
Objects.requireNonNull(subscriber);
Objects.requireNonNull(finisher);
// implicit null check
if (lineSeparator != null && lineSeparator.isEmpty())
throw new IllegalArgumentException("empty line separator");
return (status, headers) ->
BodySubscriber.fromLineSubscriber(subscriber, finisher,
charsetFrom(headers), lineSeparator);
}
/**
* Returns a response body handler which discards the response body.
*
* @return a response body handler
*/
public static BodyHandler<Void> discard() {
return (status, headers) -> BodySubscriber.discard();
}
/**
* Returns a response body handler which discards the response body and
* uses the given value as a replacement for it.
*
* @param <U> the response body type
* @param value the value of U to return as the body, may be {@code null}
* @return a response body handler
*/
public static <U> BodyHandler<U> replace(U value) {
return (status, headers) -> BodySubscriber.replace(value);
}
/**
* Returns a {@code BodyHandler<String>} that returns a
* {@link BodySubscriber BodySubscriber}{@code <String>} obtained from
* {@link BodySubscriber#asString(Charset) BodySubscriber.asString(Charset)}.
* The body is decoded using the given character set.
*
* @param charset the character set to convert the body with
* @return a response body handler
*/
public static BodyHandler<String> asString(Charset charset) {
Objects.requireNonNull(charset);
return (status, headers) -> BodySubscriber.asString(charset);
}
/**
* Returns a {@code BodyHandler<Path>} that returns a
* {@link BodySubscriber BodySubscriber}{@code <Path>} obtained from
* {@link BodySubscriber#asFile(Path, OpenOption...)
* BodySubscriber.asFile(Path,OpenOption...)}.
*
* <p> When the {@code HttpResponse} object is returned, the body has
* been completely written to the file, and {@link #body()} returns a
* reference to its {@link Path}.
*
* @param file the filename to store the body in
* @param openOptions any options to use when opening/creating the file
* @return a response body handler
* @throws SecurityException If a security manager has been installed
* and it denies {@link SecurityManager#checkWrite(String)
* write access} to the file. The {@link
* SecurityManager#checkDelete(String) checkDelete} method is
* invoked to check delete access if the file is opened with
* the {@code DELETE_ON_CLOSE} option.
*/
public static BodyHandler<Path> asFile(Path file, OpenOption... openOptions) {
Objects.requireNonNull(file);
List<OpenOption> opts = List.of(openOptions);
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
String fn = pathForSecurityCheck(file);
sm.checkWrite(fn);
if (opts.contains(StandardOpenOption.DELETE_ON_CLOSE))
sm.checkDelete(fn);
if (opts.contains(StandardOpenOption.READ))
sm.checkRead(fn);
}
return new PathBodyHandler(file, openOptions);
}
/**
* Returns a {@code BodyHandler<Path>} that returns a
* {@link BodySubscriber BodySubscriber}{@code <Path>} obtained from
* {@link BodySubscriber#asFile(Path) BodySubscriber.asFile(Path)}.
*
* <p> When the {@code HttpResponse} object is returned, the body has
* been completely written to the file, and {@link #body()} returns a
* reference to its {@link Path}.
*
* @param file the file to store the body in
* @return a response body handler
* @throws SecurityException if a security manager has been installed
* and it denies {@link SecurityManager#checkWrite(String)
* write access} to the file
*/
public static BodyHandler<Path> asFile(Path file) {
return BodyHandler.asFile(file, StandardOpenOption.CREATE,
StandardOpenOption.WRITE);
}
/**
* Returns a {@code BodyHandler<Path>} that returns a
* {@link BodySubscriber BodySubscriber}<{@link Path}>
* where the download directory is specified, but the filename is
* obtained from the {@code Content-Disposition} response header. The
* {@code Content-Disposition} header must specify the <i>attachment</i>
* type and must also contain a <i>filename</i> parameter. If the
* filename specifies multiple path components only the final component
* is used as the filename (with the given directory name).
*
* <p> When the {@code HttpResponse} object is returned, the body has
* been completely written to the file and {@link #body()} returns a
* {@code Path} object for the file. The returned {@code Path} is the
* combination of the supplied directory name and the file name supplied
* by the server. If the destination directory does not exist or cannot
* be written to, then the response will fail with an {@link IOException}.
*
* @param directory the directory to store the file in
* @param openOptions open options
* @return a response body handler
* @throws SecurityException If a security manager has been installed
* and it denies {@link SecurityManager#checkWrite(String)
* write access} to the file. The {@link
* SecurityManager#checkDelete(String) checkDelete} method is
* invoked to check delete access if the file is opened with
* the {@code DELETE_ON_CLOSE} option.
*/
//####: check if the dir exists and is writable??
public static BodyHandler<Path> asFileDownload(Path directory,
OpenOption... openOptions) {
Objects.requireNonNull(directory);
List<OpenOption> opts = List.of(openOptions);
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
String fn = pathForSecurityCheck(directory);
sm.checkWrite(fn);
if (opts.contains(StandardOpenOption.DELETE_ON_CLOSE))
sm.checkDelete(fn);
if (opts.contains(StandardOpenOption.READ))
sm.checkRead(fn);
}
return new FileDownloadBodyHandler(directory, openOptions);
}
/**
* Returns a {@code BodyHandler<InputStream>} that returns a
* {@link BodySubscriber BodySubscriber}{@code <InputStream>} obtained
* from {@link BodySubscriber#asInputStream() BodySubscriber.asInputStream}.
*
* <p> When the {@code HttpResponse} object is returned, the response
* headers will have been completely read, but the body may not have
* been fully received yet. The {@link #body()} method returns an
* {@link InputStream} from which the body can be read as it is received.
*
* @apiNote See {@link BodySubscriber#asInputStream()} for more information.
*
* @return a response body handler
*/
public static BodyHandler<InputStream> asInputStream() {
return (status, headers) -> BodySubscriber.asInputStream();
}
/**
* Returns a {@code BodyHandler<Stream<String>>} that returns a
* {@link BodySubscriber BodySubscriber}{@code <Stream<String>>} obtained from
* {@link BodySubscriber#asLines(Charset)
* BodySubscriber.asLines(charset)}.
* The {@link Charset charset} used to decode the response body bytes is
* obtained from the HTTP response headers as specified by {@link #asString()},
* and lines are delimited in the manner of {@link BufferedReader#readLine()}.
*
* <p> When the {@code HttpResponse} object is returned, the body may
* not have been completely received.
*
* @return a response body handler
*/
public static BodyHandler<Stream<String>> asLines() {
return (status, headers) ->
BodySubscriber.asLines(charsetFrom(headers));
}
/**
* Returns a {@code BodyHandler<Void>} that returns a
* {@link BodySubscriber BodySubscriber}{@code <Void>} obtained from
* {@link BodySubscriber#asByteArrayConsumer(Consumer)
* BodySubscriber.asByteArrayConsumer(Consumer)}.
*
* <p> When the {@code HttpResponse} object is returned, the body has
* been completely written to the consumer.
* @apiNote
* The subscriber returned by this handler is not flow controlled.
* Therefore, the supplied consumer must be able to process whatever
* amount of data is delivered in a timely fashion.
*
* @param consumer a Consumer to accept the response body
* @return a response body handler
*/
public static BodyHandler<Void> asByteArrayConsumer(Consumer<Optional<byte[]>> consumer) {
Objects.requireNonNull(consumer);
return (status, headers) -> BodySubscriber.asByteArrayConsumer(consumer);
}
/**
* Returns a {@code BodyHandler<byte[]>} that returns a
* {@link BodySubscriber BodySubscriber}<{@code byte[]}> obtained
* from {@link BodySubscriber#asByteArray() BodySubscriber.asByteArray()}.
*
* <p> When the {@code HttpResponse} object is returned, the body has
* been completely written to the byte array.
*
* @return a response body handler
*/
public static BodyHandler<byte[]> asByteArray() {
return (status, headers) -> BodySubscriber.asByteArray();
}
/**
* Returns a {@code BodyHandler<String>} that returns a
* {@link BodySubscriber BodySubscriber}{@code <String>} obtained from
* {@link BodySubscriber#asString(java.nio.charset.Charset)
* BodySubscriber.asString(Charset)}. The body is
* decoded using the character set specified in
* the {@code Content-type} response header. If there is no such
* header, or the character set is not supported, then
* {@link java.nio.charset.StandardCharsets#UTF_8 UTF_8} is used.
*
* <p> When the {@code HttpResponse} object is returned, the body has
* been completely written to the string.
*
* @return a response body handler
*/
public static BodyHandler<String> asString() {
return (status, headers) -> BodySubscriber.asString(charsetFrom(headers));
}
/**
* Returns a {@code BodyHandler} which, when invoked, returns a {@linkplain
* BodySubscriber#buffering(BodySubscriber,int) buffering BodySubscriber}
* that buffers data before delivering it to the downstream subscriber.
* These {@code BodySubscriber} instances are created by calling
* {@link BodySubscriber#buffering(BodySubscriber,int)
* BodySubscriber.buffering} with a subscriber obtained from the given
* downstream handler and the {@code bufferSize} parameter.
*
* @param downstreamHandler the downstream handler
* @param bufferSize the buffer size parameter passed to {@link
* BodySubscriber#buffering(BodySubscriber,int) BodySubscriber.buffering}
* @return a body handler
* @throws IllegalArgumentException if {@code bufferSize <= 0}
*/
public static <T> BodyHandler<T> buffering(BodyHandler<T> downstreamHandler,
int bufferSize) {
Objects.requireNonNull(downstreamHandler);
if (bufferSize <= 0)
throw new IllegalArgumentException("must be greater than 0");
return (status, headers) -> BodySubscriber
.buffering(downstreamHandler.apply(status, headers),
bufferSize);
}
}
/**
* A handler for push promises.
*
* <p> A <i>push promise</i> is a synthetic request sent by an HTTP/2 server
* when retrieving an initiating client-sent request. The server has
* determined, possibly through inspection of the initiating request, that
* the client will likely need the promised resource, and hence pushes a
* synthetic push request, in the form of a push promise, to the client. The
* client can choose to accept or reject the push promise request.
*
* <p> A push promise request may be received up to the point where the
* response body of the initiating client-sent request has been fully
* received. The delivery of a push promise response, however, is not
* coordinated with the delivery of the response to the initiating
* client-sent request.
*
* @param <T> the push promise response body type
*/
public interface PushPromiseHandler<T> {
/**
* Notification of an incoming push promise.
*
* <p> This method is invoked once for each push promise received, up
* to the point where the response body of the initiating client-sent
* request has been fully received.
*
* <p> A push promise is accepted by invoking the given {@code acceptor}
* function. The {@code acceptor} function must be passed a non-null
* {@code BodyHandler}, that is to be used to handle the promise's
* response body. The acceptor function will return a {@code
* CompletableFuture} that completes with the promise's response.
*
* <p> If the {@code acceptor} function is not successfully invoked,
* then the push promise is rejected. The {@code acceptor} function will
* throw an {@code IllegalStateException} if invoked more than once.
*
* @param initiatingRequest the initiating client-send request
* @param pushPromiseRequest the synthetic push request
* @param acceptor the acceptor function that must be successfully
* invoked to accept the push promise
*/
public void applyPushPromise(
HttpRequest initiatingRequest,
HttpRequest pushPromiseRequest,
Function<HttpResponse.BodyHandler<T>,CompletableFuture<HttpResponse<T>>> acceptor
);
/**
* Returns a push promise handler that accumulates push promises, and
* their responses, into the given map.
*
* <p> Entries are added to the given map for each push promise accepted.
* The entry's key is the push request, and the entry's value is a
* {@code CompletableFuture} that completes with the response
* corresponding to the key's push request. A push request is rejected /
* cancelled if there is already an entry in the map whose key is
* {@link HttpRequest#equals equal} to it. A push request is
* rejected / cancelled if it does not have the same origin as its
* initiating request.
*
* <p> Entries are added to the given map as soon as practically
* possible when a push promise is received and accepted. That way code,
* using such a map like a cache, can determine if a push promise has
* been issued by the server and avoid making, possibly, unnecessary
* requests.
*
* <p> The delivery of a push promise response is not coordinated with
* the delivery of the response to the initiating client-sent request.
* However, when the response body for the initiating client-sent
* request has been fully received, the map is guaranteed to be fully
* populated, that is, no more entries will be added. The individual
* {@code CompletableFutures} contained in the map may or may not
* already be completed at this point.
*
* @param <T> the push promise response body type
* @param pushPromiseHandler t he body handler to use for push promises
* @param pushPromisesMap a map to accumulate push promises into
* @return a push promise handler
*/
public static <T> PushPromiseHandler<T>
of(Function<HttpRequest,BodyHandler<T>> pushPromiseHandler,
ConcurrentMap<HttpRequest,CompletableFuture<HttpResponse<T>>> pushPromisesMap) {
return new PushPromisesHandlerWithMap<>(pushPromiseHandler, pushPromisesMap);
}
}
/**
* A {@code BodySubscriber} consumes response body bytes and converts them
* into a higher-level Java type.
*
* <p> The object acts as a {@link Flow.Subscriber}<{@link List}<{@link
* ByteBuffer}>> to the HTTP client implementation, which publishes
* unmodifiable lists of read-only ByteBuffers containing the response body.
* The Flow of data, as well as the order of ByteBuffers in the Flow lists,
* is a strictly ordered representation of the response body. Both the Lists
* and the ByteBuffers, once passed to the subscriber, are no longer used by
* the HTTP client. The subscriber converts the incoming buffers of data to
* some higher-level Java type {@code T}.
*
* <p> The {@link #getBody()} method returns a
* {@link CompletionStage}<{@code T}> that provides the response body
* object. The {@code CompletionStage} must be obtainable at any time. When
* it completes depends on the nature of type {@code T}. In many cases,
* when {@code T} represents the entire body after being consumed then
* the {@code CompletionStage} completes after the body has been consumed.
* If {@code T} is a streaming type, such as {@link java.io.InputStream
* InputStream}, then it completes before the body has been read, because
* the calling code uses the {@code InputStream} to consume the data.
*
* @apiNote To ensure that all resources associated with the corresponding
* HTTP exchange are properly released, an implementation of {@code
* BodySubscriber} should ensure to {@link Flow.Subscription#request
* request} more data until one of {@link #onComplete() onComplete} or
* {@link #onError(Throwable) onError} are signalled, or {@link
* Flow.Subscription#request cancel} its {@linkplain
* #onSubscribe(Flow.Subscription) subscription} if unable or unwilling to
* do so. Calling {@code cancel} before exhausting the response body data
* may cause the underlying HTTP connection to be closed and prevent it
* from being reused for subsequent operations.
*
* @param <T> the response body type
*/
public interface BodySubscriber<T>
extends Flow.Subscriber<List<ByteBuffer>> {
/**
* Returns a {@code CompletionStage} which when completed will return
* the response body object. This method can be called at any time
* relative to the other {@link Flow.Subscriber} methods and is invoked
* using the client's {@link HttpClient#executor() executor}.
*
* @return a CompletionStage for the response body
*/
public CompletionStage<T> getBody();
/**
* Returns a body subscriber that forwards all response body to the
* given {@code Flow.Subscriber}. The {@linkplain #getBody() completion
* stage} of the returned body subscriber completes after one of the
* given subscribers {@code onComplete} or {@code onError} has been
* invoked.
*
* @apiNote This method can be used as an adapter between {@code
* BodySubscriber} and {@code Flow.Subscriber}.
*
* @param <S> the type of the Subscriber
* @param subscriber the subscriber
* @return a body subscriber
*/
public static <S extends Subscriber<? super List<ByteBuffer>>> BodySubscriber<Void>
fromSubscriber(S subscriber) {
return new ResponseSubscribers.SubscriberAdapter<S,Void>(subscriber, s -> null);
}
/**
* Returns a body subscriber that forwards all response body to the
* given {@code Flow.Subscriber}. The {@linkplain #getBody() completion
* stage} of the returned body subscriber completes after one of the
* given subscribers {@code onComplete} or {@code onError} has been
* invoked.
*
* <p> The given {@code finisher} function is applied after the given
* subscriber's {@code onComplete} has been invoked. The {@code finisher}
* function is invoked with the given subscriber, and returns a value
* that is set as the response's body.
*
* @apiNote This method can be used as an adapter between {@code
* BodySubscriber} and {@code Flow.Subscriber}.
*
* @param <S> the type of the Subscriber
* @param <T> the type of the response body
* @param subscriber the subscriber
* @param finisher a function to be applied after the subscriber has
* completed
* @return a body subscriber
*/
public static <S extends Subscriber<? super List<ByteBuffer>>,T> BodySubscriber<T>
fromSubscriber(S subscriber,
Function<S,T> finisher) {
return new ResponseSubscribers.SubscriberAdapter<S,T>(subscriber, finisher);
}
/**
* Returns a body subscriber that forwards all response body to the
* given {@code Flow.Subscriber}, line by line.
* The {@linkplain #getBody() completion
* stage} of the returned body subscriber completes after one of the
* given subscribers {@code onComplete} or {@code onError} has been
* invoked.
* Bytes are decoded using the {@link StandardCharsets#UTF_8
* UTF-8} charset, and lines are delimited in the manner of
* {@link BufferedReader#readLine()}.
*
* @apiNote This method can be used as an adapter between {@code
* BodySubscriber} and {@code Flow.Subscriber}.
*
* @implNote This is equivalent to calling <pre>{@code
* fromLineSubscriber(subscriber, s -> null, StandardCharsets.UTF_8, null)
* }</pre>
*
* @param <S> the type of the Subscriber
* @param subscriber the subscriber
* @return a body subscriber
*/
public static <S extends Subscriber<? super String>> BodySubscriber<Void>
fromLineSubscriber(S subscriber) {
return fromLineSubscriber(subscriber, s -> null,
StandardCharsets.UTF_8, null);
}
/**
* Returns a body subscriber that forwards all response body to the
* given {@code Flow.Subscriber}, line by line. The {@linkplain #getBody()
* completion stage} of the returned body subscriber completes after
* one of the given subscribers {@code onComplete} or {@code onError}
* has been invoked.
*
* <p> The given {@code finisher} function is applied after the given
* subscriber's {@code onComplete} has been invoked. The {@code finisher}
* function is invoked with the given subscriber, and returns a value
* that is set as the response's body.
*
* @apiNote This method can be used as an adapter between {@code
* BodySubscriber} and {@code Flow.Subscriber}.
*
* @param <S> the type of the Subscriber
* @param <T> the type of the response body
* @param subscriber the subscriber
* @param finisher a function to be applied after the subscriber has
* completed
* @param charset a {@link Charset} to decode the bytes
* @param lineSeparator an optional line separator: can be {@code null},
* in which case lines will be delimited in the manner of
* {@link BufferedReader#readLine()}.
* @return a body subscriber
* @throws IllegalArgumentException if the supplied {@code lineSeparator} is the empty string.
*/
public static <S extends Subscriber<? super String>,T> BodySubscriber<T>
fromLineSubscriber(S subscriber,
Function<S,T> finisher,
Charset charset,
String lineSeparator) {
return LineSubscriberAdapter.create(subscriber,
finisher, charset, lineSeparator);
}
/**
* Returns a body subscriber which stores the response body as a {@code
* String} converted using the given {@code Charset}.
*
* <p> The {@link HttpResponse} using this subscriber is available after
* the entire response has been read.
*
* @param charset the character set to convert the String with
* @return a body subscriber
*/
public static BodySubscriber<String> asString(Charset charset) {
Objects.requireNonNull(charset);
return new ResponseSubscribers.ByteArraySubscriber<>(
bytes -> new String(bytes, charset)
);
}
/**
* Returns a {@code BodySubscriber} which stores the response body as a
* byte array.
*
* <p> The {@link HttpResponse} using this subscriber is available after
* the entire response has been read.
*
* @return a body subscriber
*/
public static BodySubscriber<byte[]> asByteArray() {
return new ResponseSubscribers.ByteArraySubscriber<>(
Function.identity() // no conversion
);
}
// no security check
private static BodySubscriber<Path> asFileImpl(Path file, OpenOption... openOptions) {
return new ResponseSubscribers.PathSubscriber(file, openOptions);
}
/**
* Returns a {@code BodySubscriber} which stores the response body in a
* file opened with the given options and name. The file will be opened
* with the given options using {@link FileChannel#open(Path,OpenOption...)
* FileChannel.open} just before the body is read. Any exception thrown
* will be returned or thrown from {@link HttpClient#send(HttpRequest,
* BodyHandler) HttpClient::send} or {@link HttpClient#sendAsync(HttpRequest,
* BodyHandler) HttpClient::sendAsync} as appropriate.
*
* <p> The {@link HttpResponse} using this subscriber is available after
* the entire response has been read.
*
* @param file the file to store the body in
* @param openOptions the list of options to open the file with
* @return a body subscriber
* @throws SecurityException If a security manager has been installed
* and it denies {@link SecurityManager#checkWrite(String)
* write access} to the file. The {@link
* SecurityManager#checkDelete(String) checkDelete} method is
* invoked to check delete access if the file is opened with the
* {@code DELETE_ON_CLOSE} option.
*/
public static BodySubscriber<Path> asFile(Path file, OpenOption... openOptions) {
Objects.requireNonNull(file);
List<OpenOption> opts = List.of(openOptions);
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
String fn = pathForSecurityCheck(file);
sm.checkWrite(fn);
if (opts.contains(StandardOpenOption.DELETE_ON_CLOSE))
sm.checkDelete(fn);
if (opts.contains(StandardOpenOption.READ))
sm.checkRead(fn);
}
return asFileImpl(file, openOptions);
}
/**
* Returns a {@code BodySubscriber} which stores the response body in a
* file opened with the given name. Has the same effect as calling
* {@link #asFile(Path, OpenOption...) asFile} with the standard open
* options {@code CREATE} and {@code WRITE}
*
* <p> The {@link HttpResponse} using this subscriber is available after
* the entire response has been read.
*
* @param file the file to store the body in
* @return a body subscriber
* @throws SecurityException if a security manager has been installed
* and it denies {@link SecurityManager#checkWrite(String)
* write access} to the file
*/
public static BodySubscriber<Path> asFile(Path file) {
return asFile(file, StandardOpenOption.CREATE, StandardOpenOption.WRITE);
}
/**
* Returns a {@code BodySubscriber} which provides the incoming body
* data to the provided Consumer of {@code Optional<byte[]>}. Each
* call to {@link Consumer#accept(java.lang.Object) Consumer.accept()}
* will contain a non empty {@code Optional}, except for the final
* invocation after all body data has been read, when the {@code
* Optional} will be empty.
*
* <p> The {@link HttpResponse} using this subscriber is available after
* the entire response has been read.
*
* @apiNote
* This subscriber is not flow controlled.
* Therefore, the supplied consumer must be able to process whatever
* amount of data is delivered in a timely fashion.
*
* @param consumer a Consumer of byte arrays
* @return a BodySubscriber
*/
public static BodySubscriber<Void> asByteArrayConsumer(Consumer<Optional<byte[]>> consumer) {
return new ResponseSubscribers.ConsumerSubscriber(consumer);
}
/**
* Returns a {@code BodySubscriber} which streams the response body as
* an {@link InputStream}.
*
* <p> The {@link HttpResponse} using this subscriber is available
* immediately after the response headers have been read, without
* requiring to wait for the entire body to be processed. The response
* body can then be read directly from the {@link InputStream}.
*
* @apiNote To ensure that all resources associated with the
* corresponding exchange are properly released the caller must
* ensure to either read all bytes until EOF is reached, or call
* {@link InputStream#close} if it is unable or unwilling to do so.
* Calling {@code close} before exhausting the stream may cause
* the underlying HTTP connection to be closed and prevent it
* from being reused for subsequent operations.
*
* @return a body subscriber that streams the response body as an
* {@link InputStream}.
*/
public static BodySubscriber<InputStream> asInputStream() {
return new ResponseSubscribers.HttpResponseInputStream();
}
/**
* Returns a {@code BodySubscriber} which streams the response body as
* a {@link Stream Stream<String>}, where each string in the stream
* corresponds to a line as defined by {@link BufferedReader#lines()}.
*
* <p> The {@link HttpResponse} using this subscriber is available
* immediately after the response headers have been read, without
* requiring to wait for the entire body to be processed. The response
* body can then be read directly from the {@link Stream}.
*
* @apiNote To ensure that all resources associated with the
* corresponding exchange are properly released the caller must
* ensure to either read all lines until the stream is exhausted,
* or call {@link Stream#close} if it is unable or unwilling to do so.
* Calling {@code close} before exhausting the stream may cause
* the underlying HTTP connection to be closed and prevent it
* from being reused for subsequent operations.
*
* @param charset the character set to use when converting bytes to characters
* @return a body subscriber that streams the response body as a
* {@link Stream Stream<String>}.
*
* @see BufferedReader#lines()
*/
public static BodySubscriber<Stream<String>> asLines(Charset charset) {
return ResponseSubscribers.createLineStream(charset);
}
/**
* Returns a response subscriber which discards the response body. The
* supplied value is the value that will be returned from
* {@link HttpResponse#body()}.
*
* @param <U> The type of the response body
* @param value the value to return from HttpResponse.body(), may be {@code null}
* @return a {@code BodySubscriber}
*/
public static <U> BodySubscriber<U> replace(U value) {
return new ResponseSubscribers.NullSubscriber<>(Optional.ofNullable(value));
}
/**
* Returns a response subscriber which discards the response body.
*
* @return a response body subscriber
*/
public static BodySubscriber<Void> discard() {
return new ResponseSubscribers.NullSubscriber<>(Optional.ofNullable(null));
}
/**
* Returns a {@code BodySubscriber} which buffers data before delivering
* it to the given downstream subscriber. The subscriber guarantees to
* deliver {@code buffersize} bytes of data to each invocation of the
* downstream's {@link #onNext(Object) onNext} method, except for
* the final invocation, just before {@link #onComplete() onComplete}
* is invoked. The final invocation of {@code onNext} may contain fewer
* than {@code bufferSize} bytes.
*
* <p> The returned subscriber delegates its {@link #getBody()} method
* to the downstream subscriber.
*
* @param downstream the downstream subscriber
* @param bufferSize the buffer size
* @return a buffering body subscriber
* @throws IllegalArgumentException if {@code bufferSize <= 0}
*/
public static <T> BodySubscriber<T> buffering(BodySubscriber<T> downstream,
int bufferSize) {
if (bufferSize <= 0)
throw new IllegalArgumentException("must be greater than 0");
return new BufferingSubscriber<T>(downstream, bufferSize);
}
/**
* Returns a {@code BodySubscriber} whose response body value is that of
* the result of applying the given function to the body object of the
* given {@code upstream} {@code BodySubscriber}.
*
* <p> The mapping function is executed using the client's {@linkplain
* HttpClient#executor() executor}, and can therefore be used to map any
* response body type, including blocking {@link InputStream}, as shown
* in the following example which uses a well-known JSON parser to
* convert an {@code InputStream} into any annotated Java type.
*
* <p>For example:
* <pre> {@code public static <W> BodySubscriber<W> asJSON(Class<W> targetType) {
* BodySubscriber<InputStream> upstream = BodySubscriber.asInputStream();
*
* BodySubscriber<W> downstream = mapping(
* upstream,
* (InputStream is) -> {
* try (InputStream stream = is) {
* ObjectMapper objectMapper = new ObjectMapper();
* return objectMapper.readValue(stream, targetType);
* } catch (IOException e) {
* throw new UncheckedIOException(e);
* }
* });
* return downstream;
* } }</pre>
*
* @param <T> the upstream both type
* @param <U> the type of the body subscriber returned
* @param upstream the body subscriber to be mapped
* @param mapper the mapping function
* @return a mapped body subscriber
*/
public static <T,U> BodySubscriber<U> mapping(BodySubscriber<T> upstream,
Function<T, U> mapper)
{
return new ResponseSubscribers.MappingSubscriber<T, U>(upstream, mapper);
}
}
}