O'Reilly Network Safari Bookshelf Jini Specifications, The, Second Edition in Java

Maker Code 128C in Java O'Reilly Network Safari Bookshelf Jini Specifications, The, Second Edition
O'Reilly Network Safari Bookshelf Jini Specifications, The, Second Edition
Printing USS Code 128 In Java
Using Barcode creator for Java Control to generate, create USS Code 128 image in Java applications.
The Locator Mutator Methods
Print Barcode In Java
Using Barcode maker for Java Control to generate, create bar code image in Java applications.
With respect to a particular registration, the set of locators to discover may be modified using the methods described in this section In each case, a set of locators is represented as an array of LookupLocator objects, none of whose elements may be null If any set of locators input to one of these methods contains one of more null elements, a NullPointerException is thrown Invoking any of these methods with a set of locators that contains duplicate locators (as determined by LookupLocatorequals) is equivalent to performing the invocation with the duplicates removed from the input set The addLocators method adds a set of LookupLocator objects to the registration's managed set This method takes one argument: an array consisting of the set of locators with which to augment the registration's managed set If null is passed to addLocators, a NullPointerException will be thrown If the parameter value is the empty array, the registration's managed set of locators will not change The setLocators method replaces all of the locators in the registration's managed set with LookupLocator objects from a new set This method takes one argument: an array consisting of the set of locators with which to replace the current locators in the registration's managed set If null is passed to setLocators, a NullPointerException will be thrown If the empty set is passed to setLocators, then locator discovery will be halted until the registration's managed set of locators is changed through a subsequent call to this method or to addLocators to a set that is nonnull and non empty The removeLocators method deletes a set of LookupLocator objects from the registration's managed set This method takes one argument: an array contain ing the set of LookupLocator objects to remove from the registration's managed set If null is passed to removeLocators, a NullPointerException will be thrown If any element of the set of locators to remove is not contained in the registration's managed set, removeLocators takes no action with respect to that element If the parameter value is the empty array, the managed set of locators will not change Whenever a new locator is placed in the managed set as a result of an invocation of one of the locator mutator methods and that new locator equals none of the previously discovered locators (across all registrations), the lookup discovery service will attempt unicast discovery of the lookup service associated with the new locator If locator discovery is attempted for a registration, such discovery attempts will be repeated until one of the following events occurs: The lookup service is discovered The client's lease on the registration expires The client explicitly removes the locator from the registration's managed set Upon discovery of the lookup service corresponding to the new locator, or upon finding a match between the new locator and a previously discovered lookup service, a discovered event will be sent to the registration's listener, unless that lookup service was previously discovered for that registration through group discovery Any already discovered lookup service corresponding to a locator that is removed from the registration's managed set as a result of an invocation of either setLocators or removeLocators will be discarded and will no longer be eligible for discovery, but only if it is not currently eligible for discovery through group discovery that is, only if the lookup service is not also a member of one or more of the groups in the registration's managed set of groups
Barcode Reader In Java
Using Barcode reader for Java Control to read, scan read, scan image in Java applications.
LD4 Supporting Interfaces and Classes
Code 128 Code Set B Encoder In C#
Using Barcode generation for .NET Control to generate, create Code 128B image in Visual Studio .NET applications.
O'Reilly Network Safari Bookshelf Jini Specifications, The, Second Edition
Encode Code 128A In Visual Studio .NET
Using Barcode creator for ASP.NET Control to generate, create Code 128B image in ASP.NET applications.
Discarding Lookup Services
Code 128 Printer In Visual Studio .NET
Using Barcode drawer for .NET framework Control to generate, create Code 128 Code Set C image in .NET applications.
When the lookup discovery service removes an already discovered lookup service from a registration's managed set of lookup services, the lookup service is said to be discarded There are a number of situations in which the lookup discovery service will discard a lookup service: In response to a discard request resulting from an invocation of a registration's discard method In response to a declaration via an invocation of one of the mutator methods on a registration that there is no longer any interest in one or more of the registration's already discovered lookup services In response to the determination that the multicast announcements from an already discovered lookup service indicate that the lookup service has changed its group membership in such a way that the lookup service is no longer of interest to one or more of the registrations that previously registered interest in the groups of that lookup service In response to the determination that the multicast announcements from an already discovered lookup service are no longer being received For each of these cases, whenever the lookup discovery service discards a lookup service, it will send an event to the registration's listener to notify it that the lookup service has been discarded The discard method provides a mechanism for registered clients to inform the lookup discovery service of the existence of an unavailable or unreachable lookup service, and to request that the lookup discovery service discard that lookup service and make it eligible for rediscovery The discard method takes a single argument: the proxy to the lookup service to discard This method takes no action if the parameter to this method equals none of the proxies reflected in the managed set (using proxy equality as defined in The Jini Technology Core Platform Specification, "Lookup Service" If null is passed to discard, a NullPointerException is thrown Although the lookup discovery service monitors the multicast announcements from all discovered lookup services for indications of unavailability, it should be noted that there are conditions under which the lookup discovery service will not discard such a lookup service, even when the lookup service is found to be unreachable Whether or not the lookup discovery service discards such an unreachable lookup service is dependent on how each registration is configured for discovery with respect to that lookup service If every registration that is configured to discover the unreachable lookup service is configured to discover it through locator discovery only, the lookup discovery service will not discard the lookup service In other words, in order for the lookup discovery service to discard a lookup service it has determined is unreachable, at least one registration must be configured for discovery of at least one group in which that lookup service is a member Thus, whenever a client determines that a previously discovered lookup service has become unreachable, it should not rely on the lookup discovery service to discard the lookup service Instead, the client should inform the lookup discovery service through the invocation of the registration's discard method that the previously discovered lookup service is no longer available and that attempts should be made to rediscover that lookup service for the registration Typically, a client determines that a lookup service is unavailable when the client attempts to use the lookup service but receives an indefinite exception, a bad object exception, or a bad invocation exception as a result of the attempt Note that the lookup discovery service may be acting on behalf of numerous clients that have access to the same lookup service If that lookup service becomes unavailable, many of those clients may invoke discard between the time the lookup service becomes unavailable and the time it is rediscovered Upon the first invocation of discard, the lookup discovery service will re initiate discovery of the relevant lookup service for the registration of the client that made the invocation For all other invocations made prior to rediscovery, the registrations through which the invocation is made are sent a discarded event, and added to the list of registrations that will be notified when rediscovery of the lookup service does occur That is, upon rediscovery of the lookup service, only those registrations LD4 Supporting Interfaces and Classes 260
Drawing Code 128 Code Set A In VB.NET
Using Barcode printer for VS .NET Control to generate, create Code 128 Code Set A image in Visual Studio .NET applications.
O'Reilly Network Safari Bookshelf Jini Specifications, The, Second Edition through which the discard method was invoked will be notified Upon successful completion of the discard method, the proxy requested to be discarded is guaranteed to have been removed from the managed set of the registration through which the invocation was made No such guarantee is made with respect to when the discarded event is sent to each such registration's listener That is, the event notifying the listeners that the lookup service has been discarded may or may not be sent asynchronously LD42 The RemoteDiscoveryEvent Class When the lookup discovery service discovers or discards a lookup service matching the criteria established through one of its registrations, the lookup discovery service sends an instance of the RemoteDiscoveryEvent class to the RemoteEventListener implemented by the client and registered with the lookup discovery service
Code 128 Code Set A Printer In Java
Using Barcode maker for Java Control to generate, create USS Code 128 image in Java applications.
package netjinidiscovery; public class RemoteDiscoveryEvent extends RemoteEvent { public RemoteDiscoveryEvent(Object source, long eventID, long seqNum, MarshalledObject handback, boolean discarded, Map groups) throws IOException {} public boolean isDiscarded() {} public ServiceRegistrar[] getRegistrars() throws LookupUnmarshalException {} public Map getGroups() {} }
Making USS Code 39 In Java
Using Barcode generation for Java Control to generate, create Code 3 of 9 image in Java applications.
The RemoteDiscoveryEvent class provides an encapsulation of event information that the lookup discovery service uses to notify a registration of the occurrence of an event involving one or more ServiceRegistrar objects (lookup services) in which the registration has registered interest The lookup discovery service passes an instance of this class to the registration's discovery listener when one of the following events occurs: Each lookup service referenced in the event has been discovered for the first time or rediscovered after having been discarded Each lookup service referenced in the event has been either actively or passively discarded RemoteDiscoveryEvent is a subclass of RemoteEvent, adding the following additional items of abstract state: A boolean indicating whether the lookup services referenced by the event have been discovered or discarded A set of marshalled instances of the ServiceRegistrar interface having the characteristic that when each element is unmarshalled, the result is a proxy to one of the discovered or discarded lookup services referenced by the event A Map instance in which the elements of the map's key set are the instances of ServiceID that correspond to each lookup service reference returned in the event, and the map's value set contains the corresponding member groups of each lookup service reference Methods are defined through which this additional state may be retrieved upon receipt of an instance of this class Clients need to know not only when a targeted lookup service has been discovered, but also when it has been discarded The lookup discovery service uses an instance of RemoteDiscoveryEvent to notify a registration when either of these events occurs, as indicated by the value of the boolean state variable When the value of that variable is true, the event is referred to as a discarded event; when LD4 Supporting Interfaces and Classes 261
GTIN - 13 Generation In Java
Using Barcode drawer for Java Control to generate, create EAN 13 image in Java applications.
O'Reilly Network Safari Bookshelf Jini Specifications, The, Second Edition false, it is referred to as a discovered event
Drawing Universal Product Code Version A In Java
Using Barcode creation for Java Control to generate, create UPC-A image in Java applications.
Drawing Bar Code In Java
Using Barcode creator for Java Control to generate, create barcode image in Java applications.
Data Matrix 2d Barcode Decoder In .NET
Using Barcode decoder for .NET framework Control to read, scan read, scan image in Visual Studio .NET applications.
Creating Code-39 In Visual Studio .NET
Using Barcode drawer for VS .NET Control to generate, create Code 3 of 9 image in VS .NET applications.
Create Bar Code In Visual Studio .NET
Using Barcode generator for ASP.NET Control to generate, create bar code image in ASP.NET applications.
Painting Data Matrix ECC200 In Visual Studio .NET
Using Barcode generation for .NET framework Control to generate, create DataMatrix image in .NET framework applications.