Package java.net.http

HTTP Client and WebSocket APIs

Provides high-level client interfaces to HTTP (versions 1.1 and 2) and low-level client interfaces to WebSocket. The main types defined are:

The protocol-specific requirements are defined in the Hypertext Transfer Protocol Version 2 (HTTP/2), the Hypertext Transfer Protocol (HTTP/1.1), and The WebSocket Protocol.

In general, asynchronous tasks execute in either the thread invoking the operation, e.g. sending an HTTP request, or by the threads supplied by the client's executor. Dependent tasks, those that are triggered by returned CompletionStages or CompletableFutures, that do not explicitly specify an executor, execute in the same default executor as that of CompletableFuture, or the invoking thread if the operation completes before the dependent task is registered.

CompletableFutures returned by this API will throw UnsupportedOperationException for their obtrudeValue and obtrudeException methods. Invoking the cancel method on a CompletableFuture returned by this API may not interrupt the underlying operation, but may be useful to complete, exceptionally, dependent stages that have not already completed.

Unless otherwise stated, null parameter values will cause methods of all classes in this package to throw NullPointerException.

Since:: 11

Interface Summary
Interface	Description
HttpClient.Builder	A builder of HTTP Clients.
HttpRequest.BodyPublisher	A `BodyPublisher` converts high-level Java objects into a flow of byte buffers suitable for sending as a request body.
HttpRequest.Builder	A builder of HTTP requests.
HttpResponse<T>	An HTTP response.
HttpResponse.BodyHandler<T>	A handler for response bodies.
HttpResponse.BodySubscriber<T>	A `BodySubscriber` consumes response body bytes and converts them into a higher-level Java type.
HttpResponse.PushPromiseHandler<T>	A handler for push promises.
HttpResponse.ResponseInfo	Initial response information supplied to a `BodyHandler` when a response is initially received and before the body is processed.
WebSocket	A WebSocket Client.
WebSocket.Builder	A builder of WebSocket Clients.
WebSocket.Listener	The receiving interface of `WebSocket`.

Class Summary
Class	Description
HttpClient	An HTTP Client.
HttpHeaders	A read-only view of a set of HTTP headers.
HttpRequest	An HTTP request.
HttpRequest.BodyPublishers	Implementations of `BodyPublisher` that implement various useful publishers, such as publishing the request body from a String, or from a file.
HttpResponse.BodyHandlers	Implementations of `BodyHandler` that implement various useful handlers, such as handling the response body as a String, or streaming the response body to a file.
HttpResponse.BodySubscribers	Implementations of `BodySubscriber` that implement various useful subscribers, such as converting the response body bytes into a String, or streaming the bytes to a file.

Enum Summary
Enum	Description
HttpClient.Redirect	Defines the automatic redirection policy.
HttpClient.Version	The HTTP protocol version.

Exception Summary
Exception	Description
HttpConnectTimeoutException	Thrown when a connection, over which an `HttpRequest` is intended to be sent, is not successfully established within a specified time period.
HttpTimeoutException	Thrown when a response is not received within a specified time period.
WebSocketHandshakeException	Thrown when the opening handshake has failed.