javax.sip.header
Interface ExpiresHeader

All Superinterfaces:

java.lang.Cloneable, Header, java.io.Serializable

All Known Subinterfaces:

MinExpiresHeader

public interface ExpiresHeader
extends Header

The Expires header field gives the relative time after which the message (or content) expires. The precise meaning of this is method dependent. The expiration time in an INVITE does not affect the duration of the actual session that may result from the invitation. Session description protocols may offer the ability to express time limits on the session duration, however. The value of this field is an integral number of seconds (in decimal) between 0 and (2**32)-1, measured from the receipt of the request. Malformed values SHOULD be treated as equivalent to 3600.

This interface represents the Expires entity-header. The ExpiresHeader is optional in both REGISTER and INVITE Requests.

• REGISTER - When a client sends a REGISTER request, it MAY suggest an expiration interval that indicates how long the client would like the registration to be valid. There are two ways in which a client can suggest an expiration interval for a binding: through an Expires header field or an "expires" Contact header parameter. The latter allows expiration intervals to be suggested on a per-binding basis when more than one binding is given in a single REGISTER request, whereas the former suggests an expiration interval for all Contact header field values that do not contain the "expires" parameter.
• INVITE - The UAC MAY add an Expires header field to limit the validity of the invitation. If the time indicated in the Expires header field is reached and no final answer for the INVITE has been received, the UAC core SHOULD generate a CANCEL request for the INVITE.

Example:
Expires: 5

Author:

BEA Systems, NIST

Field Summary

static java.lang.String

NAME Name of ExpiresHeader

Method Summary

int	getExpires() Gets the expires value of the ExpiresHeader.
void	setExpires(int expires) Sets the relative expires value of the ExpiresHeader in units of seconds.

Methods inherited from interface javax.sip.header.Header

clone, equals, getName, hashCode, toString

Field Detail

NAME

static final java.lang.String NAME

Name of ExpiresHeader

See Also:

Constant Field Values

Method Detail

setExpires

void setExpires(int expires)
                throws InvalidArgumentException

Sets the relative expires value of the ExpiresHeader in units of seconds. The expires value MUST be between zero and (2**31)-1.

Parameters:

expires - - the new expires value of this ExpiresHeader

Throws:

InvalidArgumentException - if supplied value is less than zero.

getExpires

int getExpires()

Gets the expires value of the ExpiresHeader. This expires value is relative time.

Returns:

the expires value of the ExpiresHeader.