com.bigdata.service.jini.lookup
Class AbstractCachingServiceClient<S extends Remote>

java.lang.Object
  com.bigdata.service.jini.lookup.AbstractCachingServiceClient<S>

Type Parameters:

S - A class or interface implemented by all services whose proxies will be discovered and cached by this class.

Direct Known Subclasses:

BigdataCachingServiceClient

public abstract class AbstractCachingServiceClient<S extends Remote>
extends Object

Abstract base class for a jini client which uses a LookupCache to reduce round trips to the discovered ServiceRegistrars for a specific class of services.

Version:

$Id$

Author:

Bryan Thompson

Field Summary

protected long	cacheMissTimeout Timeout for remote lookup on cache miss (milliseconds).
protected net.jini.lookup.ServiceItemFilter	filter The filter provided to the ctor.
protected static org.apache.log4j.Logger	log
protected net.jini.lookup.LookupCache	lookupCache A LookupCache that will be populated with all services that match a filter.
protected ServiceCache	serviceCache Provides direct cached lookup of discovered services matching both the template and the optional filter by their ServiceID.
protected net.jini.core.lookup.ServiceTemplate	template The template provided to the ctor.

Constructor Summary

AbstractCachingServiceClient(net.jini.lookup.ServiceDiscoveryManager serviceDiscoveryManager, net.jini.lookup.ServiceDiscoveryListener serviceDiscoveryListener, Class serviceIface, net.jini.core.lookup.ServiceTemplate template, net.jini.lookup.ServiceItemFilter filter, long cacheMissTimeout)
Sets up service discovery for the designed class of services.

Method Summary

void	destroyDiscoveredServices(ExecutorService executorService, net.jini.lookup.ServiceItemFilter filter) Destroy all services in the cache which match the filter.
protected boolean	destroyService(net.jini.core.lookup.ServiceItem serviceItem) Sends RemoteDestroyAdmin.destroy() request to the service.
net.jini.lookup.LookupCache	getLookupCache() An object that provides cached lookup of discovered services matching both the template and the optional filter.
S	getService() Return an arbitrary service from the cache -or- null if there is no such service in the cache and a remote lookup times out.
S	getService(net.jini.lookup.ServiceItemFilter filter) Return the proxy for an arbitrary service from the cache -or- null if there is no such service in the cache and a remote lookup times out.
ServiceCache	getServiceCache() An object that provides direct cached lookup of discovered services matching both the template and the optional filter by their ServiceID.
protected net.jini.lookup.ServiceDiscoveryManager	getServiceDiscoveryManager()
net.jini.core.lookup.ServiceItem	getServiceItem(net.jini.lookup.ServiceItemFilter filter) Return an arbitrary ServiceItem from the cache -or- null if there is no such service in the cache and a remote lookup times out.
net.jini.core.lookup.ServiceItem	getServiceItem(UUID serviceUUID) Return the ServiceItem associated with the UUID.
net.jini.core.lookup.ServiceItem[]	getServiceItems(int maxCount, net.jini.lookup.ServiceItemFilter filter) Return an array ServiceItems for up to maxCount discovered services which satisify the optional filter.
UUID[]	getServiceUUIDs(int maxCount, net.jini.lookup.ServiceItemFilter filter) Return an array UUIDs for up to maxCount discovered services which satisify the optional filter.
void	shutdownDiscoveredServices(ExecutorService executorService, net.jini.lookup.ServiceItemFilter filter, boolean immediateShutdown) Shutdown all services in the cache which match the filter.
protected boolean	shutdownService(net.jini.core.lookup.ServiceItem serviceItem, boolean immediateShutdown) Sends a shutdown request to the service.
void	terminate() Terminates asynchronous processing by the LookupCache.

Methods inherited from class java.lang.Object

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

Field Detail

log

protected static final transient org.apache.log4j.Logger log

lookupCache

protected final net.jini.lookup.LookupCache lookupCache

A LookupCache that will be populated with all services that match a filter. This is used to keep track of all services registered with any ServiceRegistrar to which the client is listening.

template

protected final net.jini.core.lookup.ServiceTemplate template

The template provided to the ctor.

filter

protected final net.jini.lookup.ServiceItemFilter filter

The filter provided to the ctor.

cacheMissTimeout

protected final long cacheMissTimeout

Timeout for remote lookup on cache miss (milliseconds).

serviceCache

protected final ServiceCache serviceCache

Provides direct cached lookup of discovered services matching both the template and the optional filter by their ServiceID.

Constructor Detail

AbstractCachingServiceClient

public AbstractCachingServiceClient(net.jini.lookup.ServiceDiscoveryManager serviceDiscoveryManager,
                                    net.jini.lookup.ServiceDiscoveryListener serviceDiscoveryListener,
                                    Class serviceIface,
                                    net.jini.core.lookup.ServiceTemplate template,
                                    net.jini.lookup.ServiceItemFilter filter,
                                    long cacheMissTimeout)
                             throws RemoteException

Sets up service discovery for the designed class of services.

Parameters:

serviceDiscoveryManager - Used to discovery services matching the template and filter.

serviceDiscoveryListener - Service discovery notices are delivered to this class.

serviceIface - The most interesting interface on the service (this is used for log messages).

template - A template used to restrict the services which are discovered and cached by this class (required).

filter - A filter used to further restrict the services which are discovered and cached by this class (optional).

cacheMissTimeout - The timeout in milliseconds that the client will await the discovery of a service if there is a cache miss.

Throws:

RemoteException - if we could not setup the LookupCache

Method Detail

getServiceDiscoveryManager

protected net.jini.lookup.ServiceDiscoveryManager getServiceDiscoveryManager()

getServiceCache

public final ServiceCache getServiceCache()

An object that provides direct cached lookup of discovered services matching both the template and the optional filter by their ServiceID.

getLookupCache

public final net.jini.lookup.LookupCache getLookupCache()

An object that provides cached lookup of discovered services matching both the template and the optional filter.

terminate

public final void terminate()

Terminates asynchronous processing by the LookupCache.

getService

public final S getService()

Return an arbitrary service from the cache -or- null if there is no such service in the cache and a remote lookup times out.

getService

public final S getService(net.jini.lookup.ServiceItemFilter filter)

Return the proxy for an arbitrary service from the cache -or- null if there is no such service in the cache and a remote lookup times out.

Parameters:

filter - An optional filter. If given it will be applied in addition to the optional filter specified to the ctor.

getServiceItem

public final net.jini.core.lookup.ServiceItem getServiceItem(net.jini.lookup.ServiceItemFilter filter)

Return an arbitrary ServiceItem from the cache -or- null if there is no such service in the cache and a remote lookup times out.

Parameters:

filter - An optional filter. If given it will be applied in addition to the optional filter specified to the ctor.

getServiceItem

public final net.jini.core.lookup.ServiceItem getServiceItem(UUID serviceUUID)

Return the ServiceItem associated with the UUID.

Parameters:

serviceUUID - The service UUID.

Returns:

The service item iff it is found in the cache and null otherwise.

getServiceItems

public net.jini.core.lookup.ServiceItem[] getServiceItems(int maxCount,
                                                          net.jini.lookup.ServiceItemFilter filter)

Return an array ServiceItems for up to maxCount discovered services which satisify the optional filter.

Parameters:

maxCount - The maximum #of data services whose UUID will be returned. When zero (0) the UUID for all known data services will be returned.

filter - An optional filter. If given it will be applied in addition to the optional filter specified to the ctor.

Returns:

An array of ServiceItems for matching discovered services.

getServiceUUIDs

public UUID[] getServiceUUIDs(int maxCount,
                              net.jini.lookup.ServiceItemFilter filter)

Return an array UUIDs for up to maxCount discovered services which satisify the optional filter.

Parameters:

maxCount - The maximum #of data services whose UUID will be returned. When zero (0) the UUID for all known data services will be returned.

filter - An optional filter. If given it will be applied in addition to the optional filter specified to the ctor.

Returns:

An array of service UUIDs for matching discovered services.

destroyDiscoveredServices

public void destroyDiscoveredServices(ExecutorService executorService,
                                      net.jini.lookup.ServiceItemFilter filter)
                               throws InterruptedException

Destroy all services in the cache which match the filter. Errors are logged for any service which could not be sent a RemoteDestroyAdmin.destroy() request.

Parameters:

filter - An optional filter. When null all services in the cache will be destroyed.

Throws:

InterruptedException

shutdownDiscoveredServices

public void shutdownDiscoveredServices(ExecutorService executorService,
                                       net.jini.lookup.ServiceItemFilter filter,
                                       boolean immediateShutdown)
                                throws InterruptedException

Shutdown all services in the cache which match the filter. Errors are logged for any service which could not be sent a RemoteDestroyAdmin.shutdown() or RemoteDestroyAdmin.shutdownNow() request.

Parameters:

filter - An optional filter. When null all services in the cache will be shutdown.

immediateShutdown - if shutdownNow() should be used.

Throws:

InterruptedException

destroyService

protected boolean destroyService(net.jini.core.lookup.ServiceItem serviceItem)
                          throws Exception

Sends RemoteDestroyAdmin.destroy() request to the service. Note that the service may process the request asynchronously.

Parameters:

serviceItem - The service item.

Returns:

true if we were able to send that message to the service.

Throws:

Exception - if anything goes wrong.

shutdownService

protected boolean shutdownService(net.jini.core.lookup.ServiceItem serviceItem,
                                  boolean immediateShutdown)
                           throws Exception

Sends a shutdown request to the service. This will invoke either RemoteDestroyAdmin.shutdown() or RemoteDestroyAdmin.shutdownNow() as indicated by the parameter. Note that the service may process the shutdown request asynchronously.

Parameters:

serviceItem - The service item.

immediateShutdown - When true uses shutdownNow().

Returns:

true if we were able to send the request to the service.

Throws:

Exception - if anything goes wrong.