Persistent Storage II: File Connection and PIM API - Beginning J2ME: From Novice to Professional - page 128

You can try out the application. Enter in a user name and a password, and then click the
Save button. You can then exit the MIDlet. When you start the MIDlet again, the persisted
information should be redisplayed.

Tip If you are using the default phone emulator of the J2ME Wireless Toolkit 2.x, the file systems are actually
subdirectories under the appdb\DefaultColorPhone\filesystem directory. You should be able to find
the preferences.pfs file storing the preference under the root1 subdirectory.

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PIM Optional Package
Many devices, especially phones, have the ability to maintain lists of phone numbers and names.
Some devices also store addresses, e-mails, events, to-do lists, and other personal information.
This PIM data is stored in PIM databases. Most devices will have built-in applications that
manage the PIM data. Until recently, there was no direct way of accessing this information
from your MIDP application. A device vendor may now expose access to its PIM databases
through the PIM Optional Package, specified in JSR 75.
Figure 9-2 shows the hierarchy of major classes and interfaces in the PIM API.

Figure 9-2. The major classes and interfaces of the JSR 75 PIM API

In Figure 9-2, PIM is a singleton object that is used to open lists of records. Think of PIM
as representing the PIM database. Lists are accessed through the PIMList interface. Each list
contains items. Each item represents a single record in the PIM database. Items are accessed
through the PIMItem interface. Contact , Event , and ToDo all inherit from PIMItem , while
ContactList , EventList , and ToDoList all inherit from PIMList .