Push registry
Normally J2ME applications start by user interaction. Let’s say you got email. Normally you must create a request and check whether new emails arrived to server or not.
Push registry enables very powerful feature of automatic activation by
- Network
- Timer
The push registry is part of the application management system (AMS), the software in the device that's responsible for each application's life-cycle (installation, activation, execution, and removal).
TCP socketsConnector.open("socket://:5000")
UDP datagramsConnector.open("datagram://:5000")
SMS Connector.open("sms://:5000")
The MIDP 2.0 specification doesn't mandate which inbound connection types must be available for push; that decision is left up to the platform vendors. Typically, though, we will have socket and datagrams available to us. Note that requesting an unsupported connection type will result in a ConnectionNotFoundException.
Problem here is TCP and UDP both need static connection to uniquely identify specific device. But local address (IP address) con be vary time to time. But phone numbers (MSISDN) are static (fixed).
So SMS-based push activation which comes with Wireless Messaging API (WMA, JSR 120) is best suite for common case. Example
reference
http://developers.sun.com/mobility/midp/articles/wma/
