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java.lang.Objectnet.rim.device.api.system.PersistentStore
public final class PersistentStore
Store for persistent objects.
The persistent store provides a means for objects to persist across device resets. A persistent object consists of a key-value pair. When a persistent object is committed to the persistent store, that object's value is stored in flash memory via a deep copy. The value can then be retrieved at a later point in time via the key.
Here is an example of a persistent address book:
import java.util.*; import net.rim.device.api.system.*; public class AddressBook { static Vector addresses; static PersistentObject persist; static { // Hash of "net.rim.sample.AddressBook". long KEY = 0xa3b3159378f59a29L; persist = PersistentStore.getPersistentObject( KEY ); addresses = (Vector) persist.getContents(); if( addresses == null ) { addresses = new Vector(); persist.setContents( addresses ); persist.commit(); } } void add( Address a ) { addresses.addElement( a ); persist.commit(); } }
Method Summary | ||
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static void |
destroyPersistentObject(long key)
Removes the persistent object from the store by its key. |
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static PersistentObject |
getPersistentObject(long key)
Retrieves a persistent object from store by its key. |
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static Object |
getSynchObject()
Retrieves the monitor object for this persistent store. |
Methods inherited from class java.lang.Object |
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equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Method Detail |
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public static PersistentObject getPersistentObject(long key)
key
- Key of object to retrieve.
public static void destroyPersistentObject(long key)
If the identified object is wrapped in a controlled access object, then the caller must have replace permissions on that object in order to destroy it.
key
- Key of object to destroy.
ControlledAccessException
- If the caller does not have replace permission.public static Object getSynchObject()
In order to perform efficient batch-commit transactions on this store, callers must synchronize the object returned by this method.
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Copyright 1993-2003 Sun Microsystems, Inc. 901 San Antonio Road, Palo Alto, California, 94303, U.S.A. All Rights Reserved.
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