com.vaadin.flow.server.communication

Class PushRequestHandler

java.lang.Object

com.vaadin.flow.server.communication.PushRequestHandler

All Implemented Interfaces:

RequestHandler, SessionExpiredHandler, Serializable

public class PushRequestHandler
extends Object
implements RequestHandler, SessionExpiredHandler

Handles requests to open a push (bidirectional) communication channel between the client and the server. After the initial request, communication through the push channel is managed by PushAtmosphereHandler and PushHandler

Since:

1.0

Author:

Vaadin Ltd

See Also:

Serialized Form

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method and Description
protected PushHandler	createPushHandler(VaadinServletService service) Creates a push handler for this request handler.
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 Detail

PushRequestHandler

public PushRequestHandler(VaadinServletService service)
                   throws ServiceException

Creates an instance connected to the given service.

Parameters:

service - the service this handler belongs to

Throws:

ServiceException - if initialization of Atmosphere fails

Method Detail

createPushHandler

protected PushHandler createPushHandler(VaadinServletService service)

Creates a push handler for this request handler.

Create your own request handler and override this method if you want to customize the PushHandler, e.g. to dynamically decide the suspend timeout.

Parameters:

service - the vaadin service

Returns:

the push handler to use for this service

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

destroy

public void destroy()

Frees any resources currently in use.

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