Jini

Jini is a framework for programming distributed applications which make special demands on the scalability and complexity of the cooperation between the different components and can not be serviced by existing techniques. Jini provides a flexible infrastructure that can deliver services (services) can be deployed in a network. Jini was developed by Sun Microsystems, based on the Java programming language.

The artificial word Jini was created when was looking for a catchy name that starts with the letter " J" for " Java". The name Jini was ultimately selected, the English word genie [ dʒi ː ni ː ] for a genie from the Arabian Nights because he sounds like. About meanings as an acronym has been speculated only retrospectively. The hallmark of Jini is an oil lamp, the dwelling of the ministering spirit in the story Aladdin and the Magic Lamp.

The Jini network technology is an open architecture that enables developers, adaptable network - based services - implemented in hardware or software - to program. With Jini scalable and flexible networks can be created as they are needed in a dynamic computer environment.

Properties

The eight fallacies of distributed applications

• The network is always available
• The waiting time (English latency ) is zero
• The transmission rate is infinitely large
• The network is secure
• The structure of the network does not change
• There is only one administrator
• The network is homogeneous

These assumptions about the network hinder the effective velocity and the distribution of the software. The following properties of the Jini network technology help to meet the above-mentioned pitfalls.

• Code mobility - The programming model of the Java programming language is transmitted to the network. It is possible that data and programs are transferred as a Java object over the network.
• Protocol - independent - allows a high flexibility in the design of the programs.
• Leasing - enables self-healing and automatic configuration of the network, which, for example, the error tolerance is increased.
• Flexibility - the network adapts to changes in the computing environment.
• Integration - allowing a simple and rapid cooperation of old, current and future network components
• Licensing - the Jini network technology is available free of charge.

Jini architecture

The Jini architecture specifies how to find clients and services on a network and can work together to resolve Asked tasks. The service providers allow clients to access the services on Java - based objects. The network communication can be done through various techniques such as RMI, CORBA or SOAP, because the client only sees the offered Java objects of the service. The actual network communication is covered by the Java object of the service.

If a service which supports Jini is started in a network, then spread this service a message about a Java object that implements the service API. The implementation of this Java object is optional for the service. A client finds services by looking for objects that provide the desired programming. Once the client has found the published object, the required tools are loaded in order to communicate with the service can. The service developer has defined how you want the communication between client and service done.

The existing Java platform makes it possible to define the Jini network technology. Jini extends the Java platform by making it available the services within the network. The Java platform defines what is at a participating machine functions. The Jini technology extends the idea of ​​a platform from a single computer to the network of computers that use the Java platform. Jini services need not necessarily exist on all computers of the network, but are available through the network on all computers.

Jini and UPnP

Jini and UPnP are different approaches in order to allow cooperation between programs and devices on a network. However, both approaches represent each prepared a different scope of implementation. For example, while Jini already presupposes an existing network for communication between the participants of the network, UPnP also provides functions to configure the network between different devices and thus enable only.