jain.protocol.ip.sip.header
Class RequireHeader

java.lang.Object
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  +--jain.protocol.ip.sip.header.Header
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        +--jain.protocol.ip.sip.header.RequestHeader
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              +--jain.protocol.ip.sip.header.RequireHeader

public final class RequireHeader

extends RequestHeader

This class representshe Require request-header. The RequireHeader is used by clients to tell user agent servers about options that the client expects the server to support in order to properly process the RequestMessage. If a server does not understand the option, it must respond by returning a BAD_EXTENSION ResponseMessage and list those options it does not understand in the UnsupportedHeader.

This is to make sure that the client-server interaction will proceed without delay when all options are understood by both sides, and only slow down if options are not understood. For a well-matched client-server pair, the interaction proceeds quickly, saving a round-trip often required by negotiation mechanisms. In addition, it also removes ambiguity when the client requires features that the server does not understand. Some features, such as call handling fields, are only of interest to end systems.

Proxy and redirect servers must ignore features that are not understood. If a particular extension requires that intermediate devices support it, the extension must be tagged in the ProxyRequireHeader as well.

Version:

0.6

See Also:

ProxyRequireHeader

Field Summary

static java.lang.String

token Token of RequireHeader

Fields inherited from class jain.protocol.ip.sip.header.Header

ENTITY_HEADER, GENERAL_HEADER, REQUEST_HEADER, RESPONSE_HEADER

Constructor Summary

RequireHeader(java.lang.String optionTag)
Creates a RequireHeader based on given option tag

Method Summary

java.lang.Object	clone() Creates and returns a copy of RequireHeader
boolean	equals(RequireHeader requireHeader) Indicates whether some other RequireHeader is "equal to" this one
java.lang.String	getOptionTag() Gets option tag of RequireHeader
java.lang.String	getValue() Gets value of RequireHeader
void	setOptionTag(java.lang.String optionTag) Sets option tag of RequireHeader

Methods inherited from class jain.protocol.ip.sip.header.Header

equals, getHeaderType, getToken, setValue, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

token

public static final java.lang.String token

Token of RequireHeader

Constructor Detail

RequireHeader

public RequireHeader(java.lang.String optionTag)
              throws java.lang.IllegalArgumentException

Creates a RequireHeader based on given option tag

Parameters:

optionTag - option tag

Throws:

java.lang.IllegalArgumentException - if optionTag is null or zero-length

Method Detail

getOptionTag

public java.lang.String getOptionTag()

Gets option tag of RequireHeader

Returns:

option tag of RequireHeader

setOptionTag

public void setOptionTag(java.lang.String optionTag)
                  throws java.lang.IllegalArgumentException

Sets option tag of RequireHeader

Parameters:

optionTag - option tag

Throws:

java.lang.IllegalArgumentException - if optionTag is null or zero-length

getValue

public java.lang.String getValue()

Gets value of RequireHeader

Overrides:

getValue in class Header

Returns:

value of RequireHeader

clone

public java.lang.Object clone()

Creates and returns a copy of RequireHeader

Overrides:

clone in class Header

equals

public boolean equals(RequireHeader requireHeader)

Indicates whether some other RequireHeader is "equal to" this one

Parameters:

requireHeader - the RequireHeader with which to compare