Interface HttpRequest.BodyPublisher
- All Superinterfaces:
Flow.Publisher<ByteBuffer>
- Enclosing class:
HttpRequest
BodyPublisher
converts high-level Java objects into a flow of
byte buffers suitable for sending as a request body. The class
BodyPublishers
provides implementations of many
common publishers.
The BodyPublisher
interface extends Flow.Publisher<ByteBuffer>
, which means that a BodyPublisher
acts as a publisher of byte buffers.
When sending a request that contains a body, the HTTP Client
subscribes to the request's BodyPublisher
in order to receive the
flow of outgoing request body data. The normal semantics of Flow.Subscriber
and Flow.Publisher
are implemented by the HTTP
Client and are expected from BodyPublisher
implementations. Each
outgoing request results in one HTTP Client 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 published to the HTTP
Client. These subscriptions complete normally when the request body 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 BodyPublisher
that reports a content length of 0
may not be subscribed to by the HTTP Client,
as it has effectively no data to publish.
- Since:
- 11
- See Also:
-
Method Summary
Modifier and TypeMethodDescriptionlong
Returns the content length for this request body.Methods declared in interface java.util.concurrent.Flow.Publisher
subscribe
-
Method Details
-
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
-