| /* |
| * 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 |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| 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.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.concurrent.Flow.Publisher; |
| import java.util.concurrent.Flow.Subscription; |
| import java.util.function.Consumer; |
| import java.util.function.Function; |
| import java.util.stream.Stream; |
| import javax.net.ssl.SSLSession; |
| 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 jdk.internal.net.http.ResponseSubscribers.PathSubscriber; |
| import static java.nio.file.StandardOpenOption.*; |
| 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. |
| * |
| * <p> The following is an example of retrieving a response as a String: |
| * |
| * <pre>{@code HttpResponse<String> response = client |
| * .send(request, BodyHandlers.ofString()); }</pre> |
| * |
| * <p> The class {@link BodyHandlers BodyHandlers} provides implementations |
| * of many common response handlers. Alternatively, a custom {@code BodyHandler} |
| * implementation can be used. |
| * |
| * @param <T> the response body type |
| * @since 11 |
| */ |
| public interface HttpResponse<T> { |
| |
| |
| /** |
| * Returns the status code for this response. |
| * |
| * @return the response code |
| */ |
| public int statusCode(); |
| |
| /** |
| * Returns the {@link HttpRequest} corresponding to this response. |
| * |
| * <p> The returned {@code HttpRequest} may not be the initiating request |
| * provided when {@linkplain HttpClient#send(HttpRequest, BodyHandler) |
| * sending}. For example, if the initiating request was redirected, then the |
| * request returned by this method will have the redirected URI, which will |
| * be different from the initiating request URI. |
| * |
| * @see #previousResponse() |
| * |
| * @return the request |
| */ |
| public 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 Optional<HttpResponse<T>> previousResponse(); |
| |
| /** |
| * Returns the received response headers. |
| * |
| * @return the response headers |
| */ |
| public 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 T body(); |
| |
| /** |
| * Returns an {@link Optional} containing the {@link SSLSession} in effect |
| * for this response. Returns an empty {@code Optional} if this is not a |
| * <i>HTTPS</i> response. |
| * |
| * @return an {@code Optional} containing the {@code SSLSession} associated |
| * with the response |
| */ |
| public Optional<SSLSession> sslSession(); |
| |
| /** |
| * 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 URI uri(); |
| |
| /** |
| * Returns the HTTP protocol version that was used for this response. |
| * |
| * @return HTTP protocol version |
| */ |
| public HttpClient.Version version(); |
| |
| |
| /** |
| * Initial response information supplied to a {@link BodyHandler BodyHandler} |
| * when a response is initially received and before the body is processed. |
| */ |
| public interface ResponseInfo { |
| /** |
| * Provides the response status code. |
| * @return the response status code |
| */ |
| public int statusCode(); |
| |
| /** |
| * Provides the response headers. |
| * @return the response headers |
| */ |
| public HttpHeaders headers(); |
| |
| /** |
| * Provides the response protocol version. |
| * @return the response protocol version |
| */ |
| public HttpClient.Version version(); |
| } |
| |
| /** |
| * A handler for response bodies. The class {@link BodyHandlers BodyHandlers} |
| * provides implementations of many common body handlers. |
| * |
| * <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, typically, converts them into a higher-level Java type. |
| * |
| * <p> A {@code BodyHandler} is a function that takes a {@link ResponseInfo |
| * ResponseInfo} object; 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> The following example uses one of the {@linkplain BodyHandlers |
| * predefined body handlers} that always process the response body in the |
| * same way ( streams the response body to a file ). |
| * |
| * <pre>{@code HttpRequest request = HttpRequest.newBuilder() |
| * .uri(URI.create("http://www.foo.com/")) |
| * .build(); |
| * client.sendAsync(request, BodyHandlers.ofFile(Paths.get("/tmp/f"))) |
| * .thenApply(HttpResponse::body) |
| * .thenAccept(System.out::println); }</pre> |
| * |
| * Note, that even though the 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<Path> bodyHandler = (rspInfo) -> rspInfo.statusCode() == 200 |
| * ? BodySubscribers.ofFile(Paths.get("/tmp/f")) |
| * : BodySubscribers.replacing(Paths.get("/NULL")); |
| * client.sendAsync(request, bodyHandler) |
| * .thenApply(HttpResponse::body) |
| * .thenAccept(System.out::println); }</pre> |
| * |
| * @param <T> the response body type |
| * @see BodyHandlers |
| * @since 11 |
| */ |
| @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 {@link BodySubscriber BodySubscriber} to consume the response |
| * body bytes. |
| * |
| * <p> The response body can be discarded using one of {@link |
| * BodyHandlers#discarding() discarding} or {@link |
| * BodyHandlers#replacing(Object) replacing}. |
| * |
| * @param responseInfo the response info |
| * @return a body subscriber |
| */ |
| public BodySubscriber<T> apply(ResponseInfo responseInfo); |
| } |
| |
| /** |
| * Implementations of {@link BodyHandler BodyHandler} that implement various |
| * useful handlers, such as handling the response body as a String, or |
| * streaming the response body to a file. |
| * |
| * <p> These implementations do not examine the status code, meaning the |
| * body is always accepted. They typically return an equivalently named |
| * {@code BodySubscriber}. Alternatively, a custom handler can be used to |
| * examine the status code and headers, and return a different body |
| * subscriber, of the same type, as appropriate. |
| * |
| * <p>The following are examples of using the predefined body handlers to |
| * convert a flow of response body data into common high-level Java objects: |
| * |
| * <pre>{@code // Receives the response body as a String |
| * HttpResponse<String> response = client |
| * .send(request, BodyHandlers.ofString()); |
| * |
| * // Receives the response body as a file |
| * HttpResponse<Path> response = client |
| * .send(request, BodyHandlers.ofFile(Paths.get("example.html"))); |
| * |
| * // Receives the response body as an InputStream |
| * HttpResponse<InputStream> response = client |
| * .send(request, BodyHandlers.ofInputStream()); |
| * |
| * // Discards the response body |
| * HttpResponse<Void> response = client |
| * .send(request, BodyHandlers.discarding()); }</pre> |
| * |
| * @since 11 |
| */ |
| public static class BodyHandlers { |
| |
| private BodyHandlers() { } |
| |
| /** |
| * Returns a response body handler that returns a {@link BodySubscriber |
| * BodySubscriber}{@code <Void>} obtained from {@link |
| * BodySubscribers#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, |
| * BodyHandlers.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 (responseInfo) -> BodySubscribers.fromSubscriber(subscriber, |
| s -> null); |
| } |
| |
| /** |
| * Returns a response body handler that returns a {@link BodySubscriber |
| * BodySubscriber}{@code <T>} obtained from {@link |
| * BodySubscribers#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, |
| * BodyHandlers.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<? super S,? extends T> finisher) { |
| Objects.requireNonNull(subscriber); |
| Objects.requireNonNull(finisher); |
| return (responseInfo) -> BodySubscribers.fromSubscriber(subscriber, |
| finisher); |
| } |
| |
| /** |
| * Returns a response body handler that returns a {@link BodySubscriber |
| * BodySubscriber}{@code <Void>} obtained from {@link |
| * BodySubscribers#fromLineSubscriber(Subscriber, Function, Charset, String) |
| * BodySubscribers.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 #ofString()}, |
| * 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 a {@code |
| * BodySubscriber} and a text based {@code Flow.Subscriber} that parses |
| * text line by line. |
| * |
| * <p> For example: |
| * <pre> {@code // A PrintSubscriber that implements Flow.Subscriber<String> |
| * // and print lines received by onNext() on System.out |
| * PrintSubscriber subscriber = new PrintSubscriber(System.out); |
| * client.sendAsync(request, BodyHandlers.fromLineSubscriber(subscriber)) |
| * .thenApply(HttpResponse::statusCode) |
| * .thenAccept((status) -> { |
| * if (status != 200) { |
| * System.err.printf("ERROR: %d status received%n", status); |
| * } |
| * }); }</pre> |
| * |
| * @param subscriber the subscriber |
| * @return a response body handler |
| */ |
| public static BodyHandler<Void> |
| fromLineSubscriber(Subscriber<? super String> subscriber) { |
| Objects.requireNonNull(subscriber); |
| return (responseInfo) -> |
| BodySubscribers.fromLineSubscriber(subscriber, |
| s -> null, |
| charsetFrom(responseInfo.headers()), |
| null); |
| } |
| |
| /** |
| * Returns a response body handler that returns a {@link BodySubscriber |
| * BodySubscriber}{@code <T>} obtained from {@link |
| * BodySubscribers#fromLineSubscriber(Subscriber, Function, Charset, String) |
| * BodySubscribers.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 #ofString()}. |
| * |
| * <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 a {@code |
| * BodySubscriber} and a text based {@code Flow.Subscriber} that parses |
| * text line by line. |
| * |
| * <p> For example: |
| * <pre> {@code // A LineParserSubscriber that implements Flow.Subscriber<String> |
| * // and accumulates lines that match a particular pattern |
| * Pattern pattern = ...; |
| * LineParserSubscriber subscriber = new LineParserSubscriber(pattern); |
| * HttpResponse<List<String>> response = client.send(request, |
| * BodyHandlers.fromLineSubscriber(subscriber, s -> s.getMatchingLines(), "\n")); |
| * if (response.statusCode() != 200) { |
| * System.err.printf("ERROR: %d status received%n", response.statusCode()); |
| * } }</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<? super S,? extends 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 (responseInfo) -> |
| BodySubscribers.fromLineSubscriber(subscriber, |
| finisher, |
| charsetFrom(responseInfo.headers()), |
| lineSeparator); |
| } |
| |
| /** |
| * Returns a response body handler that discards the response body. |
| * |
| * @return a response body handler |
| */ |
| public static BodyHandler<Void> discarding() { |
| return (responseInfo) -> BodySubscribers.discarding(); |
| } |
| |
| /** |
| * Returns a response body handler that returns the given replacement |
| * value, after discarding the response body. |
| * |
| * @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> replacing(U value) { |
| return (responseInfo) -> BodySubscribers.replacing(value); |
| } |
| |
| /** |
| * Returns a {@code BodyHandler<String>} that returns a |
| * {@link BodySubscriber BodySubscriber}{@code <String>} obtained from |
| * {@link BodySubscribers#ofString(Charset) BodySubscribers.ofString(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> ofString(Charset charset) { |
| Objects.requireNonNull(charset); |
| return (responseInfo) -> BodySubscribers.ofString(charset); |
| } |
| |
| /** |
| * Returns a {@code BodyHandler<Path>} that returns a |
| * {@link BodySubscriber BodySubscriber}{@code <Path>} obtained from |
| * {@link BodySubscribers#ofFile(Path, OpenOption...) |
| * BodySubscribers.ofFile(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}. |
| * |
| * <p> Security manager permission checks are performed in this factory |
| * method, when the {@code BodyHandler} is created. Care must be taken |
| * that the {@code BodyHandler} is not shared with untrusted code. |
| * |
| * @param file the file to store the body in |
| * @param openOptions any options to use when opening/creating the file |
| * @return a response body handler |
| * @throws IllegalArgumentException if an invalid set of open options |
| * are specified |
| * @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> ofFile(Path file, OpenOption... openOptions) { |
| Objects.requireNonNull(file); |
| List<OpenOption> opts = List.of(openOptions); |
| if (opts.contains(DELETE_ON_CLOSE) || opts.contains(READ)) { |
| // these options make no sense, since the FileChannel is not exposed |
| throw new IllegalArgumentException("invalid openOptions: " + opts); |
| } |
| return PathBodyHandler.create(file, opts); |
| } |
| |
| /** |
| * Returns a {@code BodyHandler<Path>} that returns a |
| * {@link BodySubscriber BodySubscriber}{@code <Path>}. |
| * |
| * <p> Equivalent to: {@code ofFile(file, CREATE, WRITE)} |
| * |
| * <p> Security manager permission checks are performed in this factory |
| * method, when the {@code BodyHandler} is created. Care must be taken |
| * that the {@code BodyHandler} is not shared with untrusted code. |
| * |
| * @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> ofFile(Path file) { |
| return BodyHandlers.ofFile(file, CREATE, 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}. |
| * |
| * <p> Security manager permission checks are performed in this factory |
| * method, when the {@code BodyHandler} is created. Care must be taken |
| * that the {@code BodyHandler} is not shared with untrusted code. |
| * |
| * @param directory the directory to store the file in |
| * @param openOptions open options used when opening the file |
| * @return a response body handler |
| * @throws IllegalArgumentException if the given path does not exist, |
| * is not a directory, is not writable, or if an invalid set |
| * of open options are specified |
| * @throws SecurityException If a security manager has been installed |
| * and it denies |
| * {@linkplain SecurityManager#checkRead(String) read access} |
| * to the directory, or it denies |
| * {@linkplain SecurityManager#checkWrite(String) write access} |
| * to the directory, or it denies |
| * {@linkplain SecurityManager#checkWrite(String) write access} |
| * to the files within the directory. |
| */ |
| public static BodyHandler<Path> ofFileDownload(Path directory, |
| OpenOption... openOptions) { |
| Objects.requireNonNull(directory); |
| List<OpenOption> opts = List.of(openOptions); |
| if (opts.contains(DELETE_ON_CLOSE)) { |
| throw new IllegalArgumentException("invalid option: " + DELETE_ON_CLOSE); |
| } |
| return FileDownloadBodyHandler.create(directory, opts); |
| } |
| |
| /** |
| * Returns a {@code BodyHandler<InputStream>} that returns a |
| * {@link BodySubscriber BodySubscriber}{@code <InputStream>} obtained from |
| * {@link BodySubscribers#ofInputStream() BodySubscribers.ofInputStream}. |
| * |
| * <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 BodySubscribers#ofInputStream()} for more |
| * information. |
| * |
| * @return a response body handler |
| */ |
| public static BodyHandler<InputStream> ofInputStream() { |
| return (responseInfo) -> BodySubscribers.ofInputStream(); |
| } |
| |
| /** |
| * Returns a {@code BodyHandler<Stream<String>>} that returns a |
| * {@link BodySubscriber BodySubscriber}{@code <Stream<String>>} obtained |
| * from {@link BodySubscribers#ofLines(Charset) BodySubscribers.ofLines(charset)}. |
| * The {@link Charset charset} used to decode the response body bytes is |
| * obtained from the HTTP response headers as specified by {@link #ofString()}, |
| * 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>> ofLines() { |
| return (responseInfo) -> |
| BodySubscribers.ofLines(charsetFrom(responseInfo.headers())); |
| } |
| |
| /** |
| * Returns a {@code BodyHandler<Void>} that returns a |
| * {@link BodySubscriber BodySubscriber}{@code <Void>} obtained from |
| * {@link BodySubscribers#ofByteArrayConsumer(Consumer) |
| * BodySubscribers.ofByteArrayConsumer(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> |
| ofByteArrayConsumer(Consumer<Optional<byte[]>> consumer) { |
| Objects.requireNonNull(consumer); |
| return (responseInfo) -> BodySubscribers.ofByteArrayConsumer(consumer); |
| } |
| |
| /** |
| * Returns a {@code BodyHandler<byte[]>} that returns a |
| * {@link BodySubscriber BodySubscriber}<{@code byte[]}> obtained |
| * from {@link BodySubscribers#ofByteArray() BodySubscribers.ofByteArray()}. |
| * |
| * <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[]> ofByteArray() { |
| return (responseInfo) -> BodySubscribers.ofByteArray(); |
| } |
| |
| /** |
| * Returns a {@code BodyHandler<String>} that returns a |
| * {@link BodySubscriber BodySubscriber}{@code <String>} obtained from |
| * {@link BodySubscribers#ofString(Charset) BodySubscribers.ofString(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 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> ofString() { |
| return (responseInfo) -> BodySubscribers.ofString(charsetFrom(responseInfo.headers())); |
| } |
| |
| /** |
| * Returns a {@code BodyHandler<Publisher<List<ByteBuffer>>>} that creates a |
| * {@link BodySubscriber BodySubscriber}{@code <Publisher<List<ByteBuffer>>>} |
| * obtained from {@link BodySubscribers#ofPublisher() |
| * BodySubscribers.ofPublisher()}. |
| * |
| * <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 a |
| * {@link Publisher Publisher<List<ByteBuffer>>} from which the body |
| * response bytes can be obtained as they are received. The publisher |
| * can and must be subscribed to only once. |
| * |
| * @apiNote See {@link BodySubscribers#ofPublisher()} for more |
| * information. |
| * |
| * @return a response body handler |
| */ |
| public static BodyHandler<Publisher<List<ByteBuffer>>> ofPublisher() { |
| return (responseInfo) -> BodySubscribers.ofPublisher(); |
| } |
| |
| /** |
| * Returns a {@code BodyHandler} which, when invoked, returns a {@linkplain |
| * BodySubscribers#buffering(BodySubscriber,int) buffering BodySubscriber} |
| * that buffers data before delivering it to the downstream subscriber. |
| * These {@code BodySubscriber} instances are created by calling |
| * {@link BodySubscribers#buffering(BodySubscriber,int) |
| * BodySubscribers.buffering} with a subscriber obtained from the given |
| * downstream handler and the {@code bufferSize} parameter. |
| * |
| * @param <T> the response body type |
| * @param downstreamHandler the downstream handler |
| * @param bufferSize the buffer size parameter passed to {@link |
| * BodySubscribers#buffering(BodySubscriber,int) BodySubscribers.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 (responseInfo) -> BodySubscribers |
| .buffering(downstreamHandler.apply(responseInfo), |
| 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 |
| * @since 11 |
| */ |
| 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. The class {@link BodySubscribers |
| * BodySubscriber} provides implementations of many common body subscribers. |
| * |
| * <p> The object acts as a {@link Flow.Subscriber}<{@link List}<{@link |
| * ByteBuffer}>> to the HTTP Client implementation, which publishes |
| * lists of 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. |
| * |
| * @implNote The flow of data containing the response body is immutable. |
| * Specifically, it is a flow of unmodifiable lists of read-only ByteBuffers. |
| * |
| * @param <T> the response body type |
| * @see BodySubscribers |
| * @since 11 |
| */ |
| 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(); |
| } |
| |
| /** |
| * Implementations of {@link BodySubscriber BodySubscriber} that implement |
| * various useful subscribers, such as converting the response body bytes |
| * into a String, or streaming the bytes to a file. |
| * |
| * <p>The following are examples of using the predefined body subscribers |
| * to convert a flow of response body data into common high-level Java |
| * objects: |
| * |
| * <pre>{@code // Streams the response body to a File |
| * HttpResponse<byte[]> response = client |
| * .send(request, responseInfo -> BodySubscribers.ofByteArray()); |
| * |
| * // Accumulates the response body and returns it as a byte[] |
| * HttpResponse<byte[]> response = client |
| * .send(request, responseInfo -> BodySubscribers.ofByteArray()); |
| * |
| * // Discards the response body |
| * HttpResponse<Void> response = client |
| * .send(request, responseInfo -> BodySubscribers.discarding()); |
| * |
| * // Accumulates the response body as a String then maps it to its bytes |
| * HttpResponse<byte[]> response = client |
| * .send(request, responseInfo -> |
| * BodySubscribers.mapping(BodySubscribers.ofString(UTF_8), String::getBytes)); |
| * }</pre> |
| * |
| * @since 11 |
| */ |
| public static class BodySubscribers { |
| |
| private BodySubscribers() { } |
| |
| /** |
| * Returns a body subscriber that forwards all response body to the |
| * given {@code Flow.Subscriber}. The {@linkplain BodySubscriber#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 subscriber the subscriber |
| * @return a body subscriber |
| */ |
| public static BodySubscriber<Void> |
| fromSubscriber(Subscriber<? super List<ByteBuffer>> subscriber) { |
| return new ResponseSubscribers.SubscriberAdapter<>(subscriber, s -> null); |
| } |
| |
| /** |
| * Returns a body subscriber that forwards all response body to the |
| * given {@code Flow.Subscriber}. The {@linkplain BodySubscriber#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<? super S,? extends T> finisher) { |
| return new ResponseSubscribers.SubscriberAdapter<>(subscriber, finisher); |
| } |
| |
| /** |
| * Returns a body subscriber that forwards all response body to the |
| * given {@code Flow.Subscriber}, line by line. |
| * The {@linkplain BodySubscriber#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 subscriber the subscriber |
| * @return a body subscriber |
| */ |
| public static BodySubscriber<Void> |
| fromLineSubscriber(Subscriber<? super String> 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 |
| * BodySubscriber#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<? super S,? extends 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> ofString(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[]> ofByteArray() { |
| return new ResponseSubscribers.ByteArraySubscriber<>( |
| Function.identity() // no conversion |
| ); |
| } |
| |
| /** |
| * 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. |
| * |
| * <p> Security manager permission checks are performed in this factory |
| * method, when the {@code BodySubscriber} is created. Care must be taken |
| * that the {@code BodyHandler} is not shared with untrusted code. |
| * |
| * @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 IllegalArgumentException if an invalid set of open options |
| * are specified |
| * @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> ofFile(Path file, OpenOption... openOptions) { |
| Objects.requireNonNull(file); |
| List<OpenOption> opts = List.of(openOptions); |
| if (opts.contains(DELETE_ON_CLOSE) || opts.contains(READ)) { |
| // these options make no sense, since the FileChannel is not exposed |
| throw new IllegalArgumentException("invalid openOptions: " + opts); |
| } |
| return PathSubscriber.create(file, opts); |
| } |
| |
| /** |
| * Returns a {@code BodySubscriber} which stores the response body in a |
| * file opened with the given name. |
| * |
| * <p> Equivalent to: {@code ofFile(file, CREATE, WRITE)} |
| * |
| * <p> Security manager permission checks are performed in this factory |
| * method, when the {@code BodySubscriber} is created. Care must be taken |
| * that the {@code BodyHandler} is not shared with untrusted code. |
| * |
| * @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> ofFile(Path file) { |
| return ofFile(file, CREATE, 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> |
| ofByteArrayConsumer(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> ofInputStream() { |
| 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>> ofLines(Charset charset) { |
| return ResponseSubscribers.createLineStream(charset); |
| } |
| |
| /** |
| * Returns a response subscriber which publishes the response body |
| * through a {@code Publisher<List<ByteBuffer>>}. |
| * |
| * <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 bytes can then be obtained by subscribing to the publisher |
| * returned by the {@code HttpResponse} {@link HttpResponse#body() body} |
| * method. |
| * |
| * <p>The publisher returned by the {@link HttpResponse#body() body} |
| * method can be subscribed to only once. The first subscriber will |
| * receive the body response bytes if successfully subscribed, or will |
| * cause the subscription to be cancelled otherwise. |
| * If more subscriptions are attempted, the subsequent subscribers will |
| * be immediately subscribed with an empty subscription and their |
| * {@link Subscriber#onError(Throwable) onError} method |
| * will be invoked with an {@code IllegalStateException}. |
| * |
| * @apiNote To ensure that all resources associated with the |
| * corresponding exchange are properly released the caller must |
| * ensure that the provided publisher is subscribed once, and either |
| * {@linkplain Subscription#request(long) requests} all bytes |
| * until {@link Subscriber#onComplete() onComplete} or |
| * {@link Subscriber#onError(Throwable) onError} are invoked, or |
| * cancel the provided {@linkplain Subscriber#onSubscribe(Subscription) |
| * subscription} if it is unable or unwilling to do so. |
| * Note that depending on the actual HTTP protocol {@linkplain |
| * HttpClient.Version version} used for the exchange, cancelling the |
| * subscription instead of exhausting the flow may cause the underlying |
| * HTTP connection to be closed and prevent it from being reused for |
| * subsequent operations. |
| * |
| * @return A {@code BodySubscriber} which publishes the response body |
| * through a {@code Publisher<List<ByteBuffer>>}. |
| */ |
| public static BodySubscriber<Publisher<List<ByteBuffer>>> ofPublisher() { |
| return ResponseSubscribers.createPublisher(); |
| } |
| |
| /** |
| * 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> replacing(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> discarding() { |
| 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 BodySubscriber#onNext(Object) onNext} method, |
| * except for the final invocation, just before |
| * {@link BodySubscriber#onComplete() onComplete} is invoked. The final |
| * invocation of {@code onNext} may contain fewer than {@code bufferSize} |
| * bytes. |
| * |
| * <p> The returned subscriber delegates its {@link BodySubscriber#getBody() |
| * getBody()} method to the downstream subscriber. |
| * |
| * @param <T> the type of the response body |
| * @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<>(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 = BodySubscribers.ofInputStream(); |
| * |
| * BodySubscriber<W> downstream = BodySubscribers.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 body 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 mapping body subscriber |
| */ |
| public static <T,U> BodySubscriber<U> mapping(BodySubscriber<T> upstream, |
| Function<? super T, ? extends U> mapper) |
| { |
| return new ResponseSubscribers.MappingSubscriber<>(upstream, mapper); |
| } |
| } |
| } |
