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.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	DiscoveryConstraints.ConnectionAbsoluteTimeReducer
private static class	DiscoveryConstraints.ConstraintReducer Utility for reducing constraints of a given type into a base set of alternatives.
private static class	DiscoveryConstraints.MaxValueReducer
private static class	DiscoveryConstraints.MulticastMaxPacketSizeReducer

Field Summary

Fields

Modifier and Type	Field and Description
private ConnectionAbsoluteTime	connectionAbsoluteTime
private int	hashcode
private MulticastMaxPacketSize	maxPacketSize
static Method	multicastAnnouncementMethod Method object for the multicastAnnouncement method of this class.
static Method	multicastRequestMethod Method object for the multicastRequest method of this class.
private int	preferredProtocolVersion
private Set	protocolVersions
private UnicastSocketTimeout	socketTimeout
private static Set	supportedProtocols
private MulticastTimeToLive	timeToLive
private InvocationConstraints	unfulfilled
static Method	unicastDiscoveryMethod Method object for the unicastDiscovery method of this class.

Constructor Summary

Constructors

Modifier	Constructor and Description
private	DiscoveryConstraints(InvocationConstraints constraints)

Method Summary

Methods

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.
private static int	chooseProtocolVersion(Set protocolVersions, Set protocolVersionPrefs, InvocationConstraints unfulfilled)
boolean	equals(Object o)
long	getConnectionDeadline(long defaultValue) Returns the deadline by which a network connection must be established during unicast discovery, or defaultValue if not constrained.
private static Object	getElement(Set s)
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.
private static Set	getUnfulfilled(Set constraints)
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.
int	hashCode()
private static Set	intersect(Set s1, Set s2)
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, finalize, getClass, 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.

supportedProtocols

private static final Set supportedProtocols

unfulfilled

private final InvocationConstraints unfulfilled

protocolVersions

private final Set protocolVersions

preferredProtocolVersion

private final int preferredProtocolVersion

connectionAbsoluteTime

private final ConnectionAbsoluteTime connectionAbsoluteTime

maxPacketSize

private final MulticastMaxPacketSize maxPacketSize

timeToLive

private final MulticastTimeToLive timeToLive

socketTimeout

private final UnicastSocketTimeout socketTimeout

hashcode

private final int hashcode

Constructor Detail

DiscoveryConstraints

private DiscoveryConstraints(InvocationConstraints constraints)
                      throws UnsupportedConstraintException

Throws:

UnsupportedConstraintException

Method Detail

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object o)

Overrides:

equals in class Object

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

getUnfulfilled

private static Set getUnfulfilled(Set constraints)

chooseProtocolVersion

private static int chooseProtocolVersion(Set protocolVersions,
                        Set protocolVersionPrefs,
                        InvocationConstraints unfulfilled)

intersect

private static Set intersect(Set s1,
            Set s2)

getElement

private static Object getElement(Set s)