jain.protocol.ip.sip.header
Class MaxForwardsHeader

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.MaxForwardsHeader

public final class MaxForwardsHeader

extends RequestHeader

This class represents the Max-Forwards request-header. The MaxForwardsHeader may be used with any SIP method to limit the number of proxies or gateways that can forward the RequestMessage to the next downstream server. This can also be useful when the client is attempting to trace a request chain which appears to be failing or looping in mid-chain.

The MaxForwards value is an integer indicating the remaining number of times this RequestMessage is allowed to be forwarded. Each proxy or gateway recipient of a RequestMessage containing a MaxForwardsHeader must check and update its value prior to forwarding the request. If the received value is zero (0), the recipient must not forward the RequestMessage. Instead, for OptionsMessages and RegisterMessagess, it must respond as the final recipient. For all other methods, the server returns a TOO_MANY_HOPS ResponseMessage.

If the received MaxForwards value is greater than zero, then the forwarded RequestMessage must contain an updated MaxForwardsHeader with a value decremented by one (1).

Version:

0.6

Field Summary

static java.lang.String

token Token of MaxForwardsHeader

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

ENTITY_HEADER, GENERAL_HEADER, REQUEST_HEADER, RESPONSE_HEADER

Constructor Summary

MaxForwardsHeader(int maxForwards)
Creates a MaxForwardsHeader based on given number of max-forwards

Method Summary

java.lang.Object	clone() Creates and returns a copy of MaxForwardsHeader
void	decrementMaxForwards() Decrements the number of max-forwards by one
boolean	equals(MaxForwardsHeader maxForwardsHeader) Indicates whether some other MaxForwardsHeader is "equal to" this one
int	getMaxForwards() Gets max-forwards of MaxForwardsHeader
java.lang.String	getValue() Gets value of MaxForwardsHeader
void	setMaxForwards(int maxForwards) Sets max-forwards of MaxForwardsHeader

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 MaxForwardsHeader

Constructor Detail

MaxForwardsHeader

public MaxForwardsHeader(int maxForwards)

Creates a MaxForwardsHeader based on given number of max-forwards

Parameters:

maxForwards - number of max-forwards

Throws:

java.lang.IllegalArgumentException - if maxForwards is negative

Method Detail

setMaxForwards

public void setMaxForwards(int maxForwards)
                    throws java.lang.IllegalArgumentException

Sets max-forwards of MaxForwardsHeader

Parameters:

maxForwards - number of max-forwards

Throws:

java.lang.IllegalArgumentException - if maxForwards is negative

decrementMaxForwards

public void decrementMaxForwards()

Decrements the number of max-forwards by one

getMaxForwards

public int getMaxForwards()

Gets max-forwards of MaxForwardsHeader

Returns:

max-forwards of MaxForwardsHeader

getValue

public java.lang.String getValue()

Gets value of MaxForwardsHeader

Overrides:

getValue in class Header

Returns:

value of MaxForwardsHeader

clone

public java.lang.Object clone()

Creates and returns a copy of MaxForwardsHeader

Overrides:

clone in class Header

equals

public boolean equals(MaxForwardsHeader maxForwardsHeader)

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

Parameters:

maxForwardsHeader - the MaxForwardsHeader with which to compare