com.sun.jini.discovery

Class DiscoveryConstraints

java.lang.Object

com.sun.jini.discovery.DiscoveryConstraints

public class DiscoveryConstraints
extends Object

Class for processing constraints which apply to the discovery protocol: DiscoveryProtocolVersion, MulticastMaxPacketSize, MulticastTimeToLive, UnicastSocketTimeout, ConnectionRelativeTime, ConnectionAbsoluteTime.

Since:

2.0

Author:

Sun Microsystems, Inc.

Field Summary

Fields

Modifier and Type	Field and Description
static Method	multicastAnnouncementMethod Method object for the multicastAnnouncement method of this class.
static Method	multicastRequestMethod Method object for the multicastRequest method of this class.
static Method	unicastDiscoveryMethod Method object for the unicastDiscovery method of this class.

Method Summary

Modifier and Type	Method and Description
void	checkProtocolVersion(int version) Checks the protocol version of an incoming multicast request, announcement, or unicast discovery attempt, throwing an UnsupportedConstraintException if handling of the given protocol does not satisfy the constraints of this instance.
int	chooseProtocolVersion() Returns the protocol version to use for sending multicast requests or announcements, or initiating unicast discovery.
long	getConnectionDeadline(long defaultValue) Returns the deadline by which a network connection must be established during unicast discovery, or defaultValue if not constrained.
int	getMulticastMaxPacketSize(int defaultValue) Returns the maximum multicast packet size to allow, or the specified default value if not constrained.
int	getMulticastTimeToLive(int defaultValue) Returns the multicast time to live value to use, or the specified default value if not constrained.
InvocationConstraints	getUnfulfilledConstraints() Returns the constraints for this instance which are not, or do not contain as alternatives, instances of the "fulfillable" (by this layer) constraint types DiscoveryProtocolVersion, ConnectionRelativeTime, MulticastMaxPacketSize, MulticastTimeToLive, and UnicastSocketTimeout.
int	getUnicastSocketTimeout(int defaultValue) Returns socket read timeout to use for unicast discovery, or the specified default value if not constrained.
static void	multicastAnnouncement() Empty method which serves as a MethodConstraints key for looking up InvocationConstraints that apply to multicast announcements.
static void	multicastRequest() Empty method which serves as a MethodConstraints key for looking up InvocationConstraints that apply to multicast requests.
static DiscoveryConstraints	process(InvocationConstraints constraints) Processes the discovery-related constraints in the given set of constraints, returning a DiscoveryConstraints instance from which the constraint results can be queried.
static void	unicastDiscovery() Empty method which serves as a MethodConstraints key for looking up InvocationConstraints that apply to unicast discovery.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

multicastRequestMethod

public static final Method multicastRequestMethod

Method object for the multicastRequest method of this class.

multicastAnnouncementMethod

public static final Method multicastAnnouncementMethod

Method object for the multicastAnnouncement method of this class.

unicastDiscoveryMethod

public static final Method unicastDiscoveryMethod

Method object for the unicastDiscovery method of this class.

Method Detail

multicastRequest

public static void multicastRequest()

Empty method which serves as a MethodConstraints key for looking up InvocationConstraints that apply to multicast requests.

multicastAnnouncement

public static void multicastAnnouncement()

Empty method which serves as a MethodConstraints key for looking up InvocationConstraints that apply to multicast announcements.

unicastDiscovery

public static void unicastDiscovery()

Empty method which serves as a MethodConstraints key for looking up InvocationConstraints that apply to unicast discovery.

process

public static DiscoveryConstraints process(InvocationConstraints constraints)
                                    throws UnsupportedConstraintException

Processes the discovery-related constraints in the given set of constraints, returning a DiscoveryConstraints instance from which the constraint results can be queried. Processing of timeout constraints is time dependent, and subsequent invocations of this method with the same InvocationConstraints may result in DiscoveryConstraint instances with different constraint results.

Parameters:

constraints - the constraints to process

Returns:

an instance representing processed constraints

Throws:

UnsupportedConstraintException - if the discovery-related constraints contain conflicts, or otherwise cannot be processed

NullPointerException - if constraints is null

chooseProtocolVersion

public int chooseProtocolVersion()

Returns the protocol version to use for sending multicast requests or announcements, or initiating unicast discovery.

Returns:

the protocol version to use

checkProtocolVersion

public void checkProtocolVersion(int version)
                          throws UnsupportedConstraintException

Checks the protocol version of an incoming multicast request, announcement, or unicast discovery attempt, throwing an UnsupportedConstraintException if handling of the given protocol does not satisfy the constraints of this instance.

Parameters:

version - protocol version to check

Throws:

UnsupportedConstraintException - if handling of the given protocol does not satisfy the constraints of this instance

getConnectionDeadline

public long getConnectionDeadline(long defaultValue)

Returns the deadline by which a network connection must be established during unicast discovery, or defaultValue if not constrained.

Parameters:

defaultValue - default timeout to return

Returns:

the deadline for the network connection

Since:

2.1

getMulticastMaxPacketSize

public int getMulticastMaxPacketSize(int defaultValue)

Returns the maximum multicast packet size to allow, or the specified default value if not constrained.

Parameters:

defaultValue - the value to return if the multicast packet size is unconstrained

Returns:

the maximum multicast packet size to allow

getMulticastTimeToLive

public int getMulticastTimeToLive(int defaultValue)

Returns the multicast time to live value to use, or the specified default value if not constrained.

Parameters:

defaultValue - the value to return if the multicast time to live value is unconstrained

Returns:

the multicast time to live value to use

getUnicastSocketTimeout

public int getUnicastSocketTimeout(int defaultValue)

Returns socket read timeout to use for unicast discovery, or the specified default value if not constrained.

Parameters:

defaultValue - the value to return if the socket timeout is unconstrained

Returns:

the socket timeout to use

getUnfulfilledConstraints

public InvocationConstraints getUnfulfilledConstraints()

Returns the constraints for this instance which are not, or do not contain as alternatives, instances of the "fulfillable" (by this layer) constraint types DiscoveryProtocolVersion, ConnectionRelativeTime, MulticastMaxPacketSize, MulticastTimeToLive, and UnicastSocketTimeout. Constraint alternatives containing both fulfillable and unfulfillable constraints are treated optimistically--it is assumed that the one of the fulfillable alternatives will be satisfied, so the unfulfillable alternatives are not included in the returned constraints.

Returns:

the unfulfilled constraints for this instance