Persistent Data Storage; Create A Persistent Data Store; Store Persistent Data - Blackberry JAVA DEVELOPMENT ENVIRONMENT - - DEVELOPMENT GUIDE Manual

Development Guide

Persistent data storage

Create a persistent data store

Each PersistentObject has a unique long key.
1. Import the following classes:
• net.rim.device.api.system.PersistentObject
• net.rim.device.api.system.PersistentStore
• java.lang.String
• net.rim.device.api.ui.component.Dialog
2. To create a unique long key, in the BlackBerry® Integrated Development Environment, type a string value.
com.rim.samples.docs.userinfo
3. Right-click the string and click Convert 'com.rim.samples.docs.userinfo' to long.
4. Include a comment in your code to indicate the string that you used to generate the unique long key.
5. To create a persistent data store, create a single static PersistentObject and invoke
PersistentStore.getPersistentObject, using the unique long key as a parameter.
static PersistentObject store;
static {
store = PersistentStore.getPersistentObject( 0xa1a569278238dad2L );
}

Store persistent data

1. Import the following classes:
• net.rim.device.api.system.PersistentStore
• net.rim.device.api.system.PersistentObject
2. Invoke setContents() on a PersistentObject. This method replaces existing content with the new content.
3. To save the new content to the persistent store, invoke commit().
String[] userinfo = {username, password};
synchronized(store) {
store.setContents(userinfo);
store.commit();
}
4. To use a batch transaction to commit objects to the persistent store, invoke
PersistentStore.getSynchObject(). This method retrieves the persistent store monitor that locks the
object.
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Persistent data storage