javax.sip.header

Interface MaxForwardsHeader

All Superinterfaces:

Cloneable, Header, Serializable

All Known Implementing Classes:

MaxForwards

public interface MaxForwardsHeader
extends Header

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

The Max-Forwards value is an integer in the range 0-255 indicating the remaining number of times this request message is allowed to be forwarded. This count is decremented by each server that forwards the request. The recommended initial value is 70.

This header field should be inserted by elements that can not otherwise guarantee loop detection. For example, a B2BUA should insert a Max-Forwards header field.

For Example:
Max-Forwards: 6

Version:

1.2

Author:

BEA Systems, NIST

Field Summary

Fields

Modifier and Type	Field and Description
static String	NAME Name of MaxForwardsHeader

Method Summary

Methods

Modifier and Type	Method and Description
void	decrementMaxForwards() This convenience function decrements the number of max-forwards by one.
boolean	equals(Object obj) Compare this MaxForwardsHeader for equality with another.
int	getMaxForwards() Gets the maximum number of forwards value of this MaxForwardsHeader.
void	setMaxForwards(int maxForwards) Sets the max-forwards argument of this MaxForwardsHeader to the supplied maxForwards value.

Methods inherited from interface javax.sip.header.Header

clone, getName, hashCode, toString

Field Detail

NAME

static final String NAME

Name of MaxForwardsHeader

See Also:

Constant Field Values

Method Detail

decrementMaxForwards

void decrementMaxForwards()
                          throws TooManyHopsException

This convenience function decrements the number of max-forwards by one. This utility is useful for proxy functionality.

Throws:

TooManyHopsException - if implementation cannot decrement max-fowards i.e. max-forwards has reached zero

getMaxForwards

int getMaxForwards()

Gets the maximum number of forwards value of this MaxForwardsHeader.

Returns:

the maximum number of forwards of this MaxForwardsHeader

setMaxForwards

void setMaxForwards(int maxForwards)
                    throws InvalidArgumentException

Sets the max-forwards argument of this MaxForwardsHeader to the supplied maxForwards value.

Parameters:

maxForwards - - the number of max-forwards

Throws:

InvalidArgumentException - if the maxForwards argument is less than 0 or greater than 255.

equals

boolean equals(Object obj)

Compare this MaxForwardsHeader for equality with another. This method overrides the equals method in javax.sip.Header. This method specifies object equality as outlined by RFC3261. Two MaxForwards header fields are equivalent if their max forwards integer match.

Specified by:

equals in interface Header

Overrides:

equals in class Object

Parameters:

obj - the object to compare this MaxForwardsHeader with.

Returns:

true if obj is an instance of this class representing the same MaxForwardsHeader as this, false otherwise.

Since:

v1.2