He details both the flexibility of the lookup service as well as its inherent limitations. He proposes a way for the ServiceRegistrar interface to evolve and describes the Jini team's response to his proposal. By Bill Venners he Jini lookup service, the central component of Jini's runtime infrastructure, offers Jini clients a flexible and powerful way to find Jini services. It enables service providers to advertise their services and enables clients to locate and enlist the help of those services. To interact with the lookup service, the client must first obtain a service registrar object via discovery, a network-level protocol used by Jini's runtime infrastructure.
Discovery enables clients and services to locate lookup services.
The service registrar object, which implements the net.jini.core.lookup.ServiceRegistrar interface, enables the client to interact with the lookup service. In general, a client looks up a service by Java type, usually an interface. For example, if a client needs to use a printer, it composes a service template that includes a Class object for a well-known interface to printer services. All printer services implement the interface. You can include attributes in the service template to narrow the number of matches for such a type-based search.