The Preferences API is java.util.prefs package provides
convenient way to save and recall preference data. This data should be:
relatively small (< 8kB),
accessed only occasionally
not critical
Design goals of Preferences API
should work in multithreaded, multiprocess, multilanguage environment
should work even if backing store isn't available
back-end indepenent, no explicit saving/loading
hierarchical, tree-like data store
store primitive data types as key value pairs
Use cases for Preferences API in NetBeans
user properties settable via custom options panels
windows layout configuration
These use cases are currently covered by setting infrastructure which is our way to
store persistent data. Code that utilizes settings infrastructure (like SystemOption,
TopComponent, ServiceType) could be replaced or rewritten by Preferences API.
Use cases for NetBeans specific implementation
We need an implementation that will write to somewhere in the
userdir, rather than globally because not to share a common storage area for
user preferences if someone is running :
two applications based on NetBeans
two versions of NetBeans on the same machine
newer version of a module that writes some setting that an older version can't understand
Preferences API permit, but not require, stored defaults. Applications based
on NetBeans should be able to specify default values which means:
provide default values for module private settings
brand, localize default values for the whole application
Almost all user preferences will be probably imported from previous version.
But there might be requirement to: