Class SockJsClient

java.lang.Object

org.springframework.web.socket.sockjs.client.SockJsClient

All Implemented Interfaces:

Lifecycle, WebSocketClient

public class SockJsClient
extends Object
implements WebSocketClient, Lifecycle

A SockJS implementation of WebSocketClient with fallback alternatives that simulate a WebSocket interaction through plain HTTP streaming and long polling techniques.

Implements Lifecycle in order to propagate lifecycle events to the transports it is configured with.

Since:

4.1

Author:

Rossen Stoyanchev, Sam Brannen, Juergen Hoeller

See Also:

• https://github.com/sockjs/sockjs-client
• Transport

Constructor Summary

Constructors

Constructor	Description
SockJsClient(List<Transport> transports)	Create a SockJsClient with the given transports.

Method Summary

Modifier and Type	Method	Description
protected SockJsUrlInfo	buildSockJsUrlInfo(URI url)	Create a new SockJsUrlInfo for the current client execution.
void	clearServerInfoCache()	By default, the result of a SockJS "Info" request, including whether the server has WebSocket disabled and how long the request took (used for calculating transport timeout time) is cached.
CompletableFuture<WebSocketSession>	execute(WebSocketHandler handler, String uriTemplate, @Nullable Object... uriVars)	Execute a handshake request to the given url and handle the resulting WebSocket session with the given handler.
final CompletableFuture<WebSocketSession>	execute(WebSocketHandler handler, @Nullable WebSocketHttpHeaders headers, URI url)	Execute a handshake request to the given url and handle the resulting WebSocket session with the given handler.
String @Nullable []	getHttpHeaderNames()	The configured HTTP header names to be copied from the handshake headers and also included in other HTTP requests.
InfoReceiver	getInfoReceiver()	Return the configured InfoReceiver (never null).
SockJsMessageCodec	getMessageCodec()	Return the SockJsMessageCodec to use.
protected @Nullable Principal	getUser()	Return the user to associate with the SockJS session and make available via WebSocketSession.getPrincipal().
boolean	isRunning()	Check whether this component is currently running.
void	setConnectTimeoutScheduler(TaskScheduler connectTimeoutScheduler)	Configure a TaskScheduler for scheduling a connect timeout task where the timeout value is calculated based on the duration of the initial SockJS "Info" request.
void	setHttpHeaderNames(String @Nullable ... httpHeaderNames)	The names of HTTP headers that should be copied from the handshake headers of each call to execute(WebSocketHandler, WebSocketHttpHeaders, URI) and also used with other HTTP requests issued as part of that SockJS connection, for example, the initial info request, XHR send or receive requests.
void	setInfoReceiver(InfoReceiver infoReceiver)	Configure the InfoReceiver to use to perform the SockJS "Info" request before the SockJS session starts.
void	setMessageCodec(SockJsMessageCodec messageCodec)	Set the SockJsMessageCodec to use.
void	start()	Start this component.
void	stop()	Stop this component, typically in a synchronous fashion, such that the component is fully stopped upon return of this method.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

SockJsClient

public SockJsClient(List<Transport> transports)

Create a SockJsClient with the given transports.

If the list includes an XhrTransport (or more specifically an implementation of InfoReceiver) the instance is used to initialize the infoReceiver property, or otherwise is defaulted to RestTemplateXhrTransport.

Parameters:

transports - the (non-empty) list of transports to use

Method Details

setHttpHeaderNames

public void setHttpHeaderNames(String @Nullable ... httpHeaderNames)

The names of HTTP headers that should be copied from the handshake headers of each call to execute(WebSocketHandler, WebSocketHttpHeaders, URI) and also used with other HTTP requests issued as part of that SockJS connection, for example, the initial info request, XHR send or receive requests.

By default if this property is not set, all handshake headers are also used for other HTTP requests. Set it if you want only a subset of handshake headers (for example, auth headers) to be used for other HTTP requests.

Parameters:

httpHeaderNames - the HTTP header names

getHttpHeaderNames

public String @Nullable [] getHttpHeaderNames()

The configured HTTP header names to be copied from the handshake headers and also included in other HTTP requests.

setInfoReceiver

public void setInfoReceiver(InfoReceiver infoReceiver)

Configure the InfoReceiver to use to perform the SockJS "Info" request before the SockJS session starts.

If the list of transports provided to the constructor contained an XhrTransport or an implementation of InfoReceiver that instance would have been used to initialize this property, or otherwise it defaults to RestTemplateXhrTransport.

Parameters:

infoReceiver - the transport to use for the SockJS "Info" request

getInfoReceiver

public InfoReceiver getInfoReceiver()

Return the configured InfoReceiver (never null).

setMessageCodec

public void setMessageCodec(SockJsMessageCodec messageCodec)

Set the SockJsMessageCodec to use.

By default Jackson2SockJsMessageCodec is used if Jackson is on the classpath.

getMessageCodec

public SockJsMessageCodec getMessageCodec()

Return the SockJsMessageCodec to use.

setConnectTimeoutScheduler

public void setConnectTimeoutScheduler(TaskScheduler connectTimeoutScheduler)

Configure a TaskScheduler for scheduling a connect timeout task where the timeout value is calculated based on the duration of the initial SockJS "Info" request. The connect timeout task ensures a more timely fallback but is otherwise entirely optional.

By default this is not configured in which case a fallback may take longer.

Parameters:

connectTimeoutScheduler - the task scheduler to use

start

public void start()

Description copied from interface: Lifecycle

Start this component.

Should not throw an exception if the component is already running.

In the case of a container, this will propagate the start signal to all components that apply.

Specified by:

start in interface Lifecycle

See Also:

• SmartLifecycle.isAutoStartup()

stop

public void stop()

Description copied from interface: Lifecycle

Stop this component, typically in a synchronous fashion, such that the component is fully stopped upon return of this method. Consider implementing SmartLifecycle and its stop(Runnable) variant when asynchronous stop behavior is necessary.

Note that this stop notification is not guaranteed to come before destruction: On regular shutdown, Lifecycle beans will first receive a stop notification before the general destruction callbacks are being propagated; however, on hot refresh during a context's lifetime or on aborted refresh attempts, a given bean's destroy method will be called without any consideration of stop signals upfront.

Should not throw an exception if the component is not running (not started yet).

In the case of a container, this will propagate the stop signal to all components that apply.

Specified by:

stop in interface Lifecycle

See Also:

• SmartLifecycle.stop(Runnable)
• DisposableBean.destroy()

isRunning

public boolean isRunning()

Description copied from interface: Lifecycle

Check whether this component is currently running.

In the case of a container, this will return true only if all components that apply are currently running.

Specified by:

isRunning in interface Lifecycle

Returns:

whether the component is currently running

execute

public CompletableFuture<WebSocketSession> execute(WebSocketHandler handler,
 String uriTemplate,
 @Nullable Object... uriVars)

Description copied from interface: WebSocketClient

Execute a handshake request to the given url and handle the resulting WebSocket session with the given handler.

Specified by:

execute in interface WebSocketClient

Parameters:

handler - the session handler

uriTemplate - the url template

uriVars - the variables to expand the template

Returns:

a future that completes when the session is available

execute

public final CompletableFuture<WebSocketSession> execute(WebSocketHandler handler,
 @Nullable WebSocketHttpHeaders headers,
 URI url)

Description copied from interface: WebSocketClient

Execute a handshake request to the given url and handle the resulting WebSocket session with the given handler.

Specified by:

execute in interface WebSocketClient

Parameters:

handler - the session handler

url - the url

Returns:

a future that completes when the session is available

buildSockJsUrlInfo

protected SockJsUrlInfo buildSockJsUrlInfo(URI url)

Create a new SockJsUrlInfo for the current client execution.

The default implementation builds a SockJsUrlInfo which calculates a random server id and session id if necessary.

Parameters:

url - the target URL

Since:

6.1.3

See Also:

• SockJsUrlInfo(URI)

getUser

protected @Nullable Principal getUser()

Return the user to associate with the SockJS session and make available via WebSocketSession.getPrincipal().

By default this method returns null.

Returns:

the user to associate with the session (possibly null)

clearServerInfoCache

public void clearServerInfoCache()

By default, the result of a SockJS "Info" request, including whether the server has WebSocket disabled and how long the request took (used for calculating transport timeout time) is cached. This method can be used to clear that cache hence causing it to re-populate.