The J2ME provides data record mechanism called record management system (RMS) wich provides a mechanism through which MIDlets can persistently store data and retrieve it later. In a record-oriented approach, J2ME RMS comprises multiple record stores. An overview of J2ME RMS and MIDlet interfacing is given in this picture.

Each record store can be visualized as a collection of records, which will remain persistent across multiple invocations of the MIDlet. The device platform is responsible for making its best effort to maintain the integrity of the MIDlet's record stores throughout the normal use of the platform, including reboots, battery changes, etc.

A record store is created in platform-dependent locations, like nonvolatile device memory, which are not directly exposed to the MIDlets. The RMS classes call into the platform-specific native code that uses the standard OS data manager functions to perform the actual database operations.

Record store implementations ensure that all individual record store operations are atomic, synchronous, and serialized, so no corruption of data will occur with multiple accesses. The record store is timestamped to denote the last time it was modified. The record store also maintains a version, which is an integer that is incremented for each operation that modifies the contents of the record store. Versions and timestamps are useful for synchronization purposes.

When a MIDlet uses multiple threads to access a record store, it is the MIDlet's responsibility to coordinate this access; if it fails to do so, unintended consequences may result. Similarly, if a platform performs a synchronization of a record store with multiple threads trying to access the record store simultaneously, it is the platform's responsibility to enforce exclusive access to the record store between the MIDlet and its synchronization engine.

Each record in a record store is an array of bytes and has a unique integer identifier.

ok here is the sample code try it.