@NonNullApi @NonNullFields

# Package org.springframework.web.socket.sockjs.client

SockJS client implementation of `WebSocketClient`.

See: Description

- Interface Summary
  Interface | Description
  --- | ---
  InfoReceiver | A component that can execute the SockJS "Info" request that needs to be performed before the SockJS session starts in order to check server endpoint capabilities such as whether the endpoint permits use of WebSocket.
  Transport | A client-side implementation for a SockJS transport.
  TransportRequest | Exposes information, typically to `Transport` and `session` implementations, about a request to connect to a SockJS server endpoint over a given transport.
  XhrTransport | A SockJS `Transport` that uses HTTP requests to simulate a WebSocket interaction.

- Class Summary
  Class | Description
  --- | ---
  AbstractClientSockJsSession | Base class for SockJS client implementations of `WebSocketSession`.
  AbstractXhrTransport | Abstract base class for XHR transport implementations to extend.
  JettyXhrTransport | An XHR transport based on Jetty's `HttpClient`.
  RestTemplateXhrTransport | An `XhrTransport` implementation that uses a `RestTemplate`.
  SockJsClient | A SockJS implementation of `WebSocketClient` with fallback alternatives that simulate a WebSocket interaction through plain HTTP streaming and long polling techniques.
  SockJsUrlInfo | Container for the base URL of a SockJS endpoint with additional helper methods to derive related SockJS URLs: specifically, the `info` and `transport` URLs.
  UndertowXhrTransport | An XHR transport based on Undertow's `UndertowClient`.
  WebSocketClientSockJsSession | An extension of `AbstractClientSockJsSession` wrapping and delegating to an actual WebSocket session.
  WebSocketTransport | A SockJS `Transport` that uses a `WebSocketClient`.
  XhrClientSockJsSession | An extension of `AbstractClientSockJsSession` for use with HTTP transports simulating a WebSocket session.

## Package org.springframework.web.socket.sockjs.client Description

SockJS client implementation of `WebSocketClient`.