Jini technology allows for dynamic assembly and maintenance of networks made of services and clients. It provides a simple infrastructure for delivering and accessing services across a network without human intervention. Key concepts of Jini include services, lookup services, Java RMI for communication, transactions, leasing, Java spaces, and security. Services register with lookup services, which enable clients to discover and access them. Jini supports flexibility, ease of programming, and addition of new services to a network. However, it does not scale well to very large systems and is not compatible with some limited virtual machines.

1. JINI Technology
presented
by:
sravya.s
14A81A05B1

2. Contents
Introduction to jini
Who developed jini?
What is jini?
Key concepts
How it works?
Advantages
Disadvantages
Conclusion

3. Introduction to jini
Any type of network made of services of clients of thoseAny type of network made of services of clients of those
services can be easily assembled,dissembled andservices can be easily assembled,dissembled and
maintained on the network using jini technology.maintained on the network using jini technology.
Jini technology provides a simple infrastructure forJini technology provides a simple infrastructure for
delivering services in a network and for creating andelivering services in a network and for creating an
interaction between programs that use these servicesinteraction between programs that use these services
regardless of their hardware/software implementationregardless of their hardware/software implementation

4. Who Developed JINI?
The idea of the jini system was invented by sunThe idea of the jini system was invented by sun
cofounder bill joy at sun aspen small works R&D lab incofounder bill joy at sun aspen small works R&D lab in
1994.1994.
In january 1999 download of jini realised from sunIn january 1999 download of jini realised from sun
website.website.

5. What is JINI?
 Jini is set of specifications that enables these services toJini is set of specifications that enables these services to
discover each other on a network and that provides adiscover each other on a network and that provides a
framework that allows those services to participate inframework that allows those services to participate in
certain type of operations.certain type of operations.
 Jini is all about services.Jini is all about services.
 It lets devices communicate immediately on a networkIt lets devices communicate immediately on a network
without human intervention.without human intervention.
 Jini client that loses contact with a server can recoverJini client that loses contact with a server can recover
and continue processing.and continue processing.

6. Key Concepts
ServicesServices
Lookup ServicesLookup Services
JRMIJRMI
TransactionsTransactions
LeasingLeasing
Java SpacesJava Spaces
 SecuritySecurity

7. Services
AA serviceservice can be anything that sits on the network andcan be anything that sits on the network and
is ready to perform a useful function. Hardware devices,is ready to perform a useful function. Hardware devices,
software, communications channels – even human userssoftware, communications channels – even human users
themselves -- can be servicesthemselves -- can be services
Services may be added or withdrawn from a Jini at anyServices may be added or withdrawn from a Jini at any
timetime
Services communicate by using a service protocol = set ofServices communicate by using a service protocol = set of
Java interfacesJava interfaces

8. Lookup Services
It is core of jini functionality.It is core of jini functionality.
It holds registrations of all services.It holds registrations of all services.
 Hierarchical LookupHierarchical Lookup: Lookup service may include: Lookup service may include
entry for other lookup services.entry for other lookup services.
When new services become available on the network,When new services become available on the network,
they register themselves with a lookup service.they register themselves with a lookup service.
Lookup service enables a client to query a lookup serviceLookup service enables a client to query a lookup service
for services.for services.

9. JRMI
Communication among services uses Java RMICommunication among services uses Java RMI
RMI providesRMI provides
 Distributed Garbage Collection.Distributed Garbage Collection.
 MulticastMulticast..
TransactionsTransactions
 Partial failure in distributed systems is a night mare.
 A series of operations ,either within a single service orA series of operations ,either within a single service or
multiple services can be wrapped in a transaction.multiple services can be wrapped in a transaction.

10. Leasing
A lease is a grant of guaranteed access over a timeA lease is a grant of guaranteed access over a time
period. Each lease is negotiated between the user of theperiod. Each lease is negotiated between the user of the
service and the provider of the service as part of theservice and the provider of the service as part of the
service protocol.service protocol.
Leases handle client and network failures, removal ofLeases handle client and network failures, removal of
services.services.
Leases in Jini is self-healing. Exclusive lease says serviceLeases in Jini is self-healing. Exclusive lease says service
cannot be shared.cannot be shared.

11. Security
The design of the security model for Jini technology is built on theThe design of the security model for Jini technology is built on the
twin notions:twin notions:
1)A principle.1)A principle.
2)An access control list.2)An access control list.
Security plays an important role in distributed systems. The JiniSecurity plays an important role in distributed systems. The Jini
security model is based on the JDK 1.2 security system.security model is based on the JDK 1.2 security system.
javaspacesjavaspaces
Javaspaces is a jini service that builds and maintains a database ofJavaspaces is a jini service that builds and maintains a database of
java objects.java objects.
Javaspaces provide communication through sharing java objects.Javaspaces provide communication through sharing java objects.

12. How it works
• To use a service, a person or a program locates the
service using the lookup service.
• The service's interface is copied from the lookup
service to the requesting device where it will be used.
• The lookup service acts as a switchboard to connect a
client looking for a service with that service.
• Once the connection is made, the lookup service is
not involved in any of the resulting interactions
between that client and that service

13. How it works

14. ADVANTAGES
Jini is open source.
Jini supports an extremely flexible network as services
and clients can move code to where it is needed.
New services are easy to program in java and can be
easily added to the network.

15. DISADVANTAGES
• Depends on java/RMI or external mechanism for
security.
• Does not scale well to very large systems because jini use
lookup service as a transmitter between client & services.
• One of the most restricting ones is not compatable with
the kilobyte virtual machines[sun99j],72 which is a very
limited VM.it is targeted to embedded devices with
approximately 128 kilobytes of available memory.

16. Conclusion
The overall goal is to turn the network in to flexible,
easily administered tool on which resources can be found
by human and computational clients.
Resources can be implemented as either hardware
devices , software program’s, or a combination of the
two. you can use the jini network technology to create
network technology systems that are scalable, evolvable
and flexible, in dynamic run time environments in a multi
faceted way.

17. Thank you
BbTHANK YOU