net.jini.discovery

Class LookupDiscoveryManager

java.lang.Object

net.jini.discovery.AbstractLookupDiscoveryManager

net.jini.discovery.LookupDiscoveryManager

All Implemented Interfaces:

DiscoveryGroupManagement, DiscoveryLocatorManagement, DiscoveryManagement

public final class LookupDiscoveryManager
extends AbstractLookupDiscoveryManager
implements DiscoveryManagement, DiscoveryGroupManagement, DiscoveryLocatorManagement

This class is a helper utility class that organizes and manages all discovery-related activities on behalf of a client or service. Rather than providing its own facility for coordinating and maintaining all of the necessary state information related to group names, LookupLocator objects, and DiscoveryListener objects, clients and services can employ this class to provide those facilities on their behalf.

Author:

Sun Microsystems, Inc.

See Also:

DiscoveryManagement, DiscoveryGroupManagement, DiscoveryLocatorManagement

Implementation Specifics:

The following implementation-specific items are discussed below:

• Configuring LookupDiscoveryManager
• Logging

Configuring LookupDiscoveryManager

Currently, there are no configuration entries directly supported by this implementation of LookupDiscoveryManager. All configuration entries affecting the operation of this utility are retrieved by either the LookupDiscovery utility, or the LookupLocatorDiscovery utility. Please refer to the documentation provided with those utilities when configuring the behavior of LookupDiscoveryManager.

Logging

With one exception, all logging information produced when using this utility is controlled by the loggers supported by the following utilities:

• LookupDiscovery
• LookupLocatorDiscovery

This implementation of LookupDiscoveryManager uses the Logger named net.jini.discovery.LookupDiscoveryManager to log information at the following logging levels:

net.jini.discovery.LookupDiscoveryManager

Level	Description
HANDLED	when this utility asynchronously invokes a DiscoveryListener implementation and that listener throws and unchecked exception. If the listener throws in a synchronous path (namely, via AbstractLookupDiscoveryManager.addDiscoveryListener(DiscoveryListener)) then the exception is not trapped and will instead throw back to the caller.

Nested Class Summary

Nested classes/interfaces inherited from class net.jini.discovery.AbstractLookupDiscoveryManager

AbstractLookupDiscoveryManager.LocatorDiscoveryListener, AbstractLookupDiscoveryManager.ProxyReg

Field Summary

Fields inherited from class net.jini.discovery.AbstractLookupDiscoveryManager

FROM_GROUP, FROM_LOCATOR

Fields inherited from interface net.jini.discovery.DiscoveryGroupManagement

ALL_GROUPS, NO_GROUPS

Constructor Summary

Constructors

Constructor and Description
LookupDiscoveryManager(String[] groups, LookupLocator[] locators, DiscoveryListener listener) Constructs an instance of this class that will organize and manage all discovery-related activities on behalf of the client or service that instantiates this class.
LookupDiscoveryManager(String[] groups, LookupLocator[] locators, DiscoveryListener listener, Configuration config) Constructs an instance of this class, using the given Configuration, that will organize and manage all discovery-related activities on behalf of the client or service that instantiates this class.

Method Summary

Modifier and Type	Method and Description
private static LookupDiscovery	getLookupDiscovery(String[] groups)
private static LookupLocatorDiscovery	getLookupLocatorDiscovery(LookupLocator[] locators)

Methods inherited from class net.jini.discovery.AbstractLookupDiscoveryManager

addDiscoveryListener, addGroups, addLocators, beginDiscovery, discard, getFrom, getGroups, getLocators, getRegistrars, removeDiscoveryListener, removeGroups, removeLocators, setGroups, setLocators, terminate

Methods inherited from class java.lang.Object

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

Methods inherited from interface net.jini.discovery.DiscoveryManagement

addDiscoveryListener, discard, getRegistrars, removeDiscoveryListener, terminate

Methods inherited from interface net.jini.discovery.DiscoveryGroupManagement

addGroups, getGroups, removeGroups, setGroups

Methods inherited from interface net.jini.discovery.DiscoveryLocatorManagement

addLocators, getLocators, removeLocators, setLocators

Constructor Detail

LookupDiscoveryManager

public LookupDiscoveryManager(String[] groups,
                              LookupLocator[] locators,
                              DiscoveryListener listener)
                       throws IOException

Constructs an instance of this class that will organize and manage all discovery-related activities on behalf of the client or service that instantiates this class.

If null (DiscoveryGroupManagement.ALL_GROUPS) is input to the groups parameter, then attempts will be made via group discovery to discover all lookup services located within range of the entity that constructs this class. If the empty array (DiscoveryGroupManagement.NO_GROUPS) is input to that parameter, no group discovery will be performed until the set of groups to discover is populated.

If an empty array or a null reference is input to the locators parameter, no locator discovery will be performed until the set of locators to discover is populated.

Parameters:

groups - String array, none of whose elements may be null, consisting of the names of the groups whose members are lookup services the client or service wishes to discover.

locators - array of instances of LookupLocator, none of whose elements may be null, and in which each element corresponds to a specific lookup service the client or service wishes to discover via locator discovery.

listener - a reference to DiscoveryListener object that will be notified when a targeted lookup service is discovered or discarded.

Throws:

IOException - because construction of this class may initiate the discovery process, which can throw an IOException when socket allocation occurs.

NullPointerException - this exception occurs when either one or more of the elements of the groups parameter is null, or one or more elements of the locators parameter is null.

See Also:

LookupLocator, DiscoveryListener

LookupDiscoveryManager

public LookupDiscoveryManager(String[] groups,
                              LookupLocator[] locators,
                              DiscoveryListener listener,
                              Configuration config)
                       throws IOException,
                              ConfigurationException

Constructs an instance of this class, using the given Configuration, that will organize and manage all discovery-related activities on behalf of the client or service that instantiates this class.

If null (DiscoveryGroupManagement.ALL_GROUPS) is input to the groups parameter, then attempts will be made via group discovery to discover all lookup services located within range of the entity that constructs this class. If the empty array (DiscoveryGroupManagement.NO_GROUPS) is input to that parameter, no group discovery will be performed until the set of groups to discover is populated.

If an empty array or a null reference is input to the locators parameter, no locator discovery will be performed until the set of locators to discover is populated.

Parameters:

groups - String array, none of whose elements may be null, consisting of the names of the groups whose members are lookup services the client or service wishes to discover.

locators - array of instances of LookupLocator, none of whose elements may be null, and in which each element corresponds to a specific lookup service the client or service wishes to discover via locator discovery.

listener - a reference to DiscoveryListener object that will be notified when a targeted lookup service is discovered or discarded.

config - an instance of Configuration, used to obtain the objects needed to configure the current instance of this class

Throws:

IOException - because construction of this class may initiate the discovery process, which can throw an IOException when socket allocation occurs.

ConfigurationException - indicates an exception occurred while retrieving an item from the given Configuration

NullPointerException - this exception occurs when either one or more of the elements of the groups parameter is null, or one or more elements of the locators parameter is null, or when null is input for the configuration.

See Also:

LookupLocator, DiscoveryListener, Configuration

Method Detail

getLookupDiscovery

private static LookupDiscovery getLookupDiscovery(String[] groups)
                                           throws IOException

Throws:

IOException

getLookupLocatorDiscovery

private static LookupLocatorDiscovery getLookupLocatorDiscovery(LookupLocator[] locators)
                                                         throws IOException

Throws:

IOException