javax.servlet.sip

Interface SessionKeepAlive

public interface SessionKeepAlive

Represents Session Keep Alive as specified in RFC 4028. An application may use this interface to schedule refresh and expiry tasks, which will be executed by the container for keeping the session alive and expiring the session respectively.

Since:

2.0

See Also:

SipSession.getKeepAlive()

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	SessionKeepAlive.Callback An implementation of this interface may be set on the SessionKeepAlive as a refresh task and/or expiry callback.
static interface	SessionKeepAlive.Preference Holds the preference data in the SIP message headers.
static class	SessionKeepAlive.Refresher Represents the refresher type.

Method Summary

Methods

Modifier and Type	Method and Description
int	getExpirationInterval() Returns the expiration interval in seconds, beyond with session will expire.
SessionKeepAlive.Callback	getExpiryCallback() Return the expiry task set in the session.
long	getLastExpirationTime() Returns the last time a session refresh request is sent, received or proxied with this session, as the number of milliseconds since midnight January 1, 1970 GMT.
SessionKeepAlive.Callback	getRefreshCallback() Return the task that was previously set using setRefreshTask method.
long	getRemainingTime() For a UAC return the remaining time for sending the next refresh request in seconds.
boolean	isRefresher() Returns whether the session is a UA that assumed the role of refresher.
void	setExpiryCallback(SessionKeepAlive.Callback callback) Set the callback that will be executed by the container for sending the session termination request.
void	setRefreshCallback(SessionKeepAlive.Callback callback) Set the callback that will be executed by the container for sending the refresh request.

Method Detail

isRefresher

boolean isRefresher()

Returns whether the session is a UA that assumed the role of refresher. A refresher is tasked with sending session refresh requests.

Returns:

True if the session represents a UA and that UA is the refresher. False otherwise.

getExpirationInterval

int getExpirationInterval()

Returns the expiration interval in seconds, beyond with session will expire. Will return -1, if the session keep alive is not enabled in this session.

Returns:

Session expiration interval in seconds.

getLastExpirationTime

long getLastExpirationTime()

Returns the last time a session refresh request is sent, received or proxied with this session, as the number of milliseconds since midnight January 1, 1970 GMT. Will return -1, if a session refresh request is not sent, received or proxied on this session yet.

Returns:

a long representing the last time the a session refresh request is sent,received or proxied with this session, expressed in milliseconds since 1/1/1970 GMT

getRemainingTime

long getRemainingTime()

For a UAC return the remaining time for sending the next refresh request in seconds. For a UAS or proxy, this will be equal to getExpirationInterval Will return -1 if the session keep alive is not enabled in this session.

Returns:

Time remaining for sending the next refresh request.

setRefreshCallback

void setRefreshCallback(SessionKeepAlive.Callback callback)

Set the callback that will be executed by the container for sending the refresh request. Application may set null to remove the already set callback.

Parameters:

callback - Callback that will be executed by the container for sending refresh request.

See Also:

SessionKeepAlive.Callback

getRefreshCallback

SessionKeepAlive.Callback getRefreshCallback()

Return the task that was previously set using setRefreshTask method.

Returns:

Refresh task to send refresh requests.

setExpiryCallback

void setExpiryCallback(SessionKeepAlive.Callback callback)

Set the callback that will be executed by the container for sending the session termination request. Application may set null to remove the already set callback.

Parameters:

callback - The expiry callback to send session termination requests.

getExpiryCallback

SessionKeepAlive.Callback getExpiryCallback()

Return the expiry task set in the session.

Returns:

The expiry task to send the session termination requests.