Download J2ME and the IVY platform

J2ME and the
IVY Platform
Confidential & Proprietary Information of Digital Focus
Agenda
Digital Focus
J2ME
•
•
•
Quick overview
What’s in & what’s out
Networking capabilities
IVY & JXTA
•
•
•
Why and what
IVY Architecture and Design
JXTA protocols and components
Confidential & Proprietary Information of Digital Focus
Digital Focus
Founded in 1995
Headquartered in Herndon, Virginia
Long history of excellence with Java technology…
Confidential & Proprietary Information of Digital Focus
Our Clients
Confidential & Proprietary Information of Digital Focus
J2ME
J2ME – Java 2 MicroEdition
•
•
Java for small, mobile and embedded devices
Configurations (horizontal)
•
•
CLDC, CDC
Profiles (vertical)
•
MIDP, Foundation, Palm
Confidential & Proprietary Information of Digital Focus
J2ME Architecture
CLDC Configuration
•
•
•
KVM, networking
Lowest common
denominator for
portability
No optional elements
MID profile
•
•
•
•
GUI
RMS
Timers
Lifecycle
Confidential & Proprietary Information of Digital Focus
What’s missing
Reduced number support
•
•
float, double primitives
Double, Float classes
Extendable UI components
•
•
Final High-level components
New components subclass Canvas
Lacks:
•
•
•
•
•
JNI
Sound API
Serialization
Reflection
User defined class loaders
Confidential & Proprietary Information of Digital Focus
Networking
Only HTTP is required with CLDC
•
•
•
Not great for mobile wireless solutions
Stateful – tough with mobile IP
Stream oriented
Generic Connection Framework
•
•
Opens protocol support (sockets, serial,
datagram,…)
Runtime binding to protocol
J2ME generally designed as a “client”
However:
•
•
Can be a Datagram server
Interfaces exist for socket serving
Confidential & Proprietary Information of Digital Focus
“Designing for small places”
Device resources limit OO design
•
•
Use objects judiciously – consider patterns like Flyweight
Use lazy instantiation where feasible
Design tradeoffs:
•
•
•
Classes, methods (encapsulation vs space)
Inheritance (saves space, increases cpu)
Names (maintainability vs space)
•
Use an obfuscator
Optimizations
•
•
•
Reuse objects; avoid needless re-instantiation
StringBuffer vs String
Use String wrappers when hashing
Confidential & Proprietary Information of Digital Focus
Devices
RIM 5180
Nokia 9120
Nextel
I85s
Kyocera
Confidential & Proprietary Information of Digital Focus
Sprint
Confidential & Proprietary Information of Digital Focus
What is it?
Lightweight wireless platform for Mobile to Mobile
(M2M) collaboration
•
Every Peer is a client, server and router
Enables rapid development
•
•
•
Easy, low cost entry
Provides API for locating, communicating with and sharing
services between groups/peers
Supports Web-enabled start-up and authentication
Open standards-based
•
•
Web Services, JXTA
XML
Built for wireless Java
•
•
•
J2ME (MIDP/CLDC)
Personal Java
CVM & Foundation Profile
Confidential & Proprietary Information of Digital Focus
Why IVY
Growing demand for P2P applications
• Groove Networks
• Games, Instant messaging
• Napster, GNUtella
• Mesh Networks
Technology is available
• Programmable, wireless devices
•
•
•
•
•
•
Nextel’s I85
RIM’s 5820 J2ME/GPRS support
Nokia 9210 (personal java and MIDP)
RIM 8150
Over the air provisioning
Investment in 2.5G infrastructure
Network providers want to increase data usage
Confidential & Proprietary Information of Digital Focus
What & Why not JXTA?
What is JXTA
•
•
www.jxta.org
Mainly 6 protocols
Is IVY compliant with JXTA? No, but almost
•
•
•
Uses JXTA protocols
JXTA requires TCP/IP and/or HTTP;
Datagram/UDP not supported
Why use Datagrams
•
•
Optimal for wireless networks.
Network providers use datagrams under WAP, HTTP and
sockets.
Why not use JXME (JXTA’s J2ME project)
•
•
•
Very early stages
Uses TCP/Http and centralized “super server”
Polling architecture. Not really P2P?
Confidential & Proprietary Information of Digital Focus
JXTA
High-level abstraction
•
•
•
Hides complexity of physical network
Single uniform addressability for all peers
Simple model for discovery, addressing and service sharing
Based on JXTA – 6 protocols
•
•
•
•
•
•
Peer Discovery
Peer Resolver
Peer Information
Peer Membership
Pipe Binding
Endpoint routing
XML messages
•
•
Text
Binary
1 Request & 1 Response
•
Stateless
Confidential & Proprietary Information of Digital Focus
Group
Peer
Peer Peer
Endpoint
Service
Advertisement
Pipe
Conceptual Architecture
APIs
Peer , groups
Services, Ads
Pipes
User Interface
Protocols & Formats
Peers and Groups
•
•
•
•
•
JXTA XML & binary
SOAP/WSDL
Messages
•
•
•
Full duplex
Datagrams
HTTP,HTTPS
Cross Platform
•
•
J2ME
J2SE
Confidential & Proprietary Information of Digital Focus
Web Svcs
Services
(soap,wsdl)
Ads
Pipes
Protocols and Formats
Messages
Service-oriented Architecture
Confidential & Proprietary Information of Digital Focus
Key Design Drivers
Network connectivity
•
•
Asynchronous API with listeners
Datagrams with reliable upper level
Minimize server dependency
•
•
Peer Group advertisements
Get credentials
Small footprint
•
•
Implement “needed” protocols
30K un-obfuscated
JXTA compliant
Confidential & Proprietary Information of Digital Focus
Java Packages
Ivy.api – Just interfaces and factories for
services and abstracts (pipes, messages,
peers, endpoints)
Ivy.impl – Implementations for the ivy.api
package
Ivy.util – constants and static methods
Ivy.net – Differs whether J2ME or J2SE
Ivy.exception
Confidential & Proprietary Information of Digital Focus
Contact Information
Digital Focus, Inc.
13825 Sunrise Valley Drive
Suite 220
Herndon, VA 20171
www.digitalfocus.com
Tom Whitcomb
Chief Technology Officer
[email protected]
703.561.5884
or
Dave Hoffman
Vice President
[email protected]
703.561.5963
Confidential & Proprietary Information of Digital Focus