Package com.vaadin.flow.server.communication

Class SseRequestHandler

java.lang.Object

com.vaadin.flow.server.communication.SseRequestHandler

All Implemented Interfaces:

RequestHandler, SessionExpiredHandler, Serializable

public class SseRequestHandler
extends Object
implements RequestHandler, SessionExpiredHandler

Handles requests to open an SSE (Server-Sent Events) push connection between the client and the server. SSE is a unidirectional server-to-client channel; client-to-server messages continue to use XHR.

This handler does not use the Atmosphere framework.

For internal use only. May be renamed or removed in a future release.

Since:

24.7

Author:

Vaadin Ltd

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
SseRequestHandler(VaadinServletService service)	Creates an instance connected to the given service.

Method Summary

Modifier and Type	Method	Description
void	destroy()	Frees any resources currently in use.
boolean	handleRequest(VaadinSession session, VaadinRequest request, VaadinResponse response)	Called when a request needs to be handled.
boolean	handleSessionExpired(VaadinRequest request, VaadinResponse response)	Called when the a session expiration has occurred and a notification needs to be sent to the user.

Methods inherited from class java.lang.Object

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

Constructor Details

SseRequestHandler

public SseRequestHandler(VaadinServletService service)

Creates an instance connected to the given service.

Parameters:

service - the service this handler belongs to

Method Details

handleRequest

public boolean handleRequest(VaadinSession session,
 VaadinRequest request,
 VaadinResponse response)
                      throws IOException

Description copied from interface: RequestHandler

Called when a request needs to be handled. If a response is written, this method should return true to indicate that no more request handlers should be invoked for the request.

Note that request handlers by default do not lock the session. If you are using VaadinSession or anything inside the VaadinSession you must ensure the session is locked. This can be done by extending SynchronizedRequestHandler or by using VaadinSession.accessSynchronously(Command) or UI.accessSynchronously(Command).

Specified by:

handleRequest in interface RequestHandler

Parameters:

session - The session for the request

request - The request to handle

response - The response object to which a response can be written.

Returns:

true if a response has been written and no further request handlers should be called, otherwise false

Throws:

IOException - If an IO error occurred

handleSessionExpired

public boolean handleSessionExpired(VaadinRequest request,
 VaadinResponse response)
                             throws IOException

Description copied from interface: SessionExpiredHandler

Called when the a session expiration has occurred and a notification needs to be sent to the user. If a response is written, this method should return true to indicate that no more SessionExpiredHandler handlers should be invoked for the request.

Specified by:

handleSessionExpired in interface SessionExpiredHandler

Parameters:

request - The request to handle

response - The response object to which a response can be written.

Returns:

true if a response has been written and no further request handlers should be called, otherwise false

Throws:

IOException - If an IO error occurred

destroy

public void destroy()

Frees any resources currently in use.