net.rim.device.api.util
Interface Persistable

All Known Subinterfaces:

Accessory, AuthInfo, AsymmetricCryptoToken, CryptoSystem, CryptoToken, CryptoTokenCryptoSystemData, CryptoTokenMACKeyData, CryptoTokenPrivateKeyData, CryptoTokenPublicKeyData, CryptoTokenSymmetricKeyData, DHKey, DSAKey, ECKey, KEAKey, Key, PrivateKey, PublicKey, RSAKey, SymmetricCryptoToken, SymmetricKey, Certificate, DistinguishedName, KeyStoreData

All Known Implementing Classes:

BiometricData, FingerprintBiometricData, BigIntVector, BigLongVector, BigVector, SparseList, AESCryptoToken, AESKey, ARC4Key, CAST128CryptoToken, CAST128Key, CryptoSmartCard, CryptoSmartCardKeyStoreData, DESCryptoToken, DESKey, DHCryptoSystem, DHCryptoToken, DHKeyPair, DHPrivateKey, DHPublicKey, DSACryptoSystem, DSACryptoToken, DSAKeyPair, DSAPrivateKey, DSAPublicKey, ECCryptoSystem, ECCryptoToken, ECKeyPair, ECPrivateKey, ECPublicKey, HMACCryptoToken, HMACKey, InitializationVector, KEACryptoSystem, KEACryptoToken, KEAKeyPair, KEAPrivateKey, KEAPublicKey, KeyPair, RC2CryptoToken, RC2Key, RC5CryptoToken, RC5Key, RSACryptoSystem, RSACryptoToken, RSAKeyPair, RSAPrivateKey, RSAPublicKey, SkipjackCryptoToken, SkipjackKey, SmartCardDSACryptoToken, SmartCardRSACryptoToken, TripleDESCryptoToken, TripleDESKey, ASN1BitSet, CertificateExtension, CertificateServerInfo, CertificateServers, CertificateStatus, WTLSCertificate, WTLSDistinguishedName, X509Certificate, X509DistinguishedName, CMSReceiptData, AssociatedData, OID, DatagramBase, FileInfo, HttpHeaders, ObjectPathHashtableBase, JSONHashtable, XMLHashtable, LatLonRectangle, AbstractMappable, MapComplexPolygon, MapImage, MapLine, MapLocation, MapMarker, MapPoint, MapPolyLine, MapSimplePolygon, PeerPoint, GsFolder, GsImage, GsLine, GsMarker, GsPoint, GsPolyLine, GsPolygon, GsRoot, Style, StyleSet, ServiceBook, ServiceBook.ServiceStatus, ServiceRecord, SmartCard, SmartCardID, CodeSigningKey, ControlledAccess, PersistentObject, PersistentStore, UserAuthenticatorContextObject, ByteVector, ContentProtectedHashtable, ContentProtectedVector, DataBuffer, IntHashtable, IntIntHashtable, IntLongHashtable, IntMultiMap, IntStack, IntVector, LongHashtable, LongIntHashtable, LongStack, LongVector, MultiMap, SimpleSortingIntVector, StringMatch, ToIntHashtable, ToLongHashtable, HotspotCredentialsAgent

public interface Persistable

Every object that can persist between handheld resets must implement persistable. The Persistable interface does not declare any methods to implement. It is an empty interface used to mark a class as persistable.

A class must explicitly implement this interface for the system to persistently store instances of the class. Sub-classes do not inherit implementation of this interface. In the following example, Bar instances cannot persist, because the class does not explicitly implement the Persistable interface (if you attempt to store a Bar object in the persistent store, the device will raise a JVM error):

 
  class Foo extends Vector implements Persistable { // }
  class Bar extends Foo { // }
 

Here are some key points you should note about persistant data:

• Classes may remain compatible with old instances kept in persistent storage, but the configuration of instance data in the class (and all its superclasses) must not change.
• Adding classes or significantly altering their number and order of methods within the COD files on the device will most likely result in persistent data stored on the device becoming unusable and being removed upon a reset.
• Removing a COD containing class definitions for any persisted instances will result in the device removing the persisted instances upon a reset.
• You should assume that persistent data must be backed up and restored whenever any code on the device is changed; your application will need to provide a means for receiving and re-encoding backed up data.