Workshop minutes on the Jini Pattern Language
This document tries to cover the key ideas discussed during the
workshop at OOPSLA 2000. We will try to capture the ideas in their
original unmodified form.
The following is a list of key items discussed.
- Direction of Jini - Jini is going to evolve from where it is
now. As Jim Waldo explained, some of the new directions may be:
- Surrogate proxies
- Jini and EJB interoperation
- Further integration of JavaSpaces
- Searching for a simple, yet powerful, security mechanism
- Discovered patterns - Many of the presentations aimed
at finding patterns in Jini and ad hoc networking in general.
Presentations, which were mainly focusing on patterns are:
- Event Pipeline Pattern, by Bina Ramamurthy
- Pick and Verify Pattern, discovered in UPnP, by Markus Wischy
- Service-Oriented Programming Pattern Language, by Guy
- Locate and Track Pattern, by Bruce Cohen
- Profile-based Service Browsing, by Martin Gitsels
- User Interface Pattern, by Vrijendra Gokhale
- Jini and Components - Jim Waldo scratched the topic
with the EJB/Jini integration slightly. It got covered in detail
by Guy Biebers presentation about the OpenWings project. During
that presentation, it became clear that service-oriented
programming, which he is suggesting, bases on component -
container contracts. A component is the deployment unit of a
Also the JinACE presentation of the workshop organizers has
been pointing into that direction. However the focus here was
not restricted to Java, but to ad hoc networking in
general. Some ideas include making the CORBA Component Model
(CCM) ad hoc capable by merging it with dynamic scenarios from
the Jini world. The other direction, of making todays ad hoc
networking frameworks, like Jini, more component-oriented, by
introducing techniques like the deployment and configuration
scenarios, from EJB and CCM.
- Location awareness - in ad hoc networking seems to be one
of the big problems and therefor an important field of research.
Fabio Kon raised some issues, problems in this field. With the
"2k Name Service Browser" he showed how they tackled the
problem in their environment.
Bruce Cohen aimed at the same problem with his Locate and
Track pattern, where he suggests to make the location one of
the criterias of the service discovery.
The "Profile-based Service Browsing" presentation aimed at a
similar direction, where services would register with a
profile, possibly containing location information, which gets
then used for enhanced searches on the services.
Location awareness can be seen as one of several parameters
found by reflection on the environment the service is running
- Scaling down - The currently available frameworks for
ad hoc networking are too big to fit on todays small
devices. Jim Waldo and Fabio Kon mentioned some ideas around
- Surrogate architecture in Jini
- Proxies at various levels responsible for gateway
- Bridges between technologies, e.g. Jini/CORBA
- Suggested areas of work - Due to the complexity of
the themes and the restricted time we left the workshop with
many open questions. Here a list of them:
- How to standardize location awareness?
- Discover more patterns, e.g. in the areas of Security,
Proxies, Bridges and Federations.
- Find a simple but efficient security mechanism
appropriate for small devices
- Simplicty - ad hoc networking frameworks should be
simple in the core and extensible with services around
- How can loaded services be replaced? Jini specifies how
services get loaded, but how do they get unloaded?
- Relection techniques might be of matter to specific
domains of small devices. How can such information be
accessed in a standard way?
Last modified: Mon Nov 13 22:20:58 W. Europe Standard Time 2000