Module jdk.incubator.httpclient
Package jdk.incubator.http

Interface HttpRequest.BodyPublisher

  • All Superinterfaces:
    Flow.Publisher<ByteBuffer>
    Enclosing class:
    HttpRequest
    public static interface HttpRequest.BodyPublisher
extends Flow.Publisher<ByteBuffer>
    A Publisher which converts high level Java objects into flows of byte buffers suitable for sending as request bodies.
    Incubating Feature. Will be removed in a future release.

    The BodyPublisher class implements Flow.Publisher<ByteBuffer> which means that a BodyPublisher acts as a publisher of byte buffers.

    The HTTP client implementation subscribes to the publisher in order to receive the flow of outgoing data buffers. The normal semantics of Flow.Subscriber and Flow.Publisher are implemented by the library and are expected from publisher implementations. Each outgoing request results in one Subscriber subscribing to the BodyPublisher in order to provide the sequence of byte buffers containing the request body. Instances of ByteBuffer published by the publisher must be allocated by the publisher, and must not be accessed after being handed over to the library. These subscriptions complete normally when the request is fully sent, and can be canceled or terminated early through error. If a request needs to be resent for any reason, then a new subscription is created which is expected to generate the same data as before.

    A publisher that reports a content length of 0 may not be subscribed to by the HTTP client implementation, as it has effectively no data to publish.

    • Method Detail

      • fromPublisher

        static HttpRequest.BodyPublisher fromPublisher​(Flow.Publisher<? extends ByteBuffer> publisher)
        Returns a request body publisher whose body is retrieved from the given Flow.Publisher. The returned request body publisher has an unknown content length.
        API Note:
        This method can be used as an adapter between BodyPublisher and Flow.Publisher, where the amount of request body that the publisher will publish is unknown.
        Parameters:
        publisher - the publisher responsible for publishing the body
        Returns:
        a BodyPublisher

      • fromPublisher

        static HttpRequest.BodyPublisher fromPublisher​(Flow.Publisher<? extends ByteBuffer> publisher,
                                               long contentLength)
        Returns a request body publisher whose body is retrieved from the given Flow.Publisher. The returned request body publisher has the given content length.

        The given contentLength is a positive number, that represents the exact amount of bytes the publisher must publish.

        API Note:
        This method can be used as an adapter between BodyPublisher and Flow.Publisher, where the amount of request body that the publisher will publish is known.
        Parameters:
        publisher - the publisher responsible for publishing the body
        contentLength - a positive number representing the exact amount of bytes the publisher will publish
        Returns:
        a BodyPublisher
        Throws:
        IllegalArgumentException - if the content length is non-positive

      • fromString

        static HttpRequest.BodyPublisher fromString​(String body)
        Returns a request body publisher whose body is the given String, converted using the UTF_8 character set.
        Parameters:
        body - the String containing the body
        Returns:
        a BodyPublisher

      • fromString

        static HttpRequest.BodyPublisher fromString​(String s,
                                            Charset charset)
        Returns a request body publisher whose body is the given String, converted using the given character set.
        Parameters:
        s - the String containing the body
        charset - the character set to convert the string to bytes
        Returns:
        a BodyPublisher

      • fromInputStream

        static HttpRequest.BodyPublisher fromInputStream​(Supplier<? extends InputStream> streamSupplier)
        A request body publisher that reads its data from an InputStream. A Supplier of InputStream is used in case the request needs to be repeated, as the content is not buffered. The Supplier may return null on subsequent attempts, in which case the request fails.
        Parameters:
        streamSupplier - a Supplier of open InputStreams
        Returns:
        a BodyPublisher

      • fromByteArray

        static HttpRequest.BodyPublisher fromByteArray​(byte[] buf)
        Returns a request body publisher whose body is the given byte array.
        Parameters:
        buf - the byte array containing the body
        Returns:
        a BodyPublisher

      • fromByteArray

        static HttpRequest.BodyPublisher fromByteArray​(byte[] buf,
                                               int offset,
                                               int length)
        Returns a request body publisher whose body is the content of the given byte array of length bytes starting from the specified offset.
        Parameters:
        buf - the byte array containing the body
        offset - the offset of the first byte
        length - the number of bytes to use
        Returns:
        a BodyPublisher
        Throws:
        IndexOutOfBoundsException - if the sub-range is defined to be out-of-bounds

      • fromByteArrays

        static HttpRequest.BodyPublisher fromByteArrays​(Iterable<byte[]> iter)
        A request body publisher that takes data from an Iterable of byte arrays. An Iterable is provided which supplies Iterator instances. Each attempt to send the request results in one invocation of the Iterable.
        Parameters:
        iter - an Iterable of byte arrays
        Returns:
        a BodyPublisher

      • noBody

        static HttpRequest.BodyPublisher noBody()
        A request body publisher which sends no request body.
        Returns:
        a BodyPublisher which completes immediately and sends no request body.

      • contentLength

        long contentLength()
        Returns the content length for this request body. May be zero if no request body being sent, greater than zero for a fixed length content, or less than zero for an unknown content length. This method may be invoked before the publisher is subscribed to. This method may be invoked more than once by the HTTP client implementation, and MUST return the same constant value each time.
        Returns:
        the content length for this request body, if known