Package com.sleepycat.bind.serial

Class SerialSerialKeyCreator<PK,D,SK>

java.lang.Object

com.sleepycat.bind.serial.SerialSerialKeyCreator<PK,D,SK>

All Implemented Interfaces:

ForeignKeyNullifier, SecondaryKeyCreator

public abstract class SerialSerialKeyCreator<PK,D,SK>
extends java.lang.Object
implements SecondaryKeyCreator, ForeignKeyNullifier

A abstract key creator that uses a serial key and a serial data entry. This class takes care of serializing and deserializing the key and data entry automatically. The following abstract method must be implemented by a concrete subclass to create the index key using these objects

• createSecondaryKey(Object,Object)

If ForeignKeyDeleteAction.NULLIFY was specified when opening the secondary database, the following method must be overridden to nullify the foreign index key. If NULLIFY was not specified, this method need not be overridden.

• nullifyForeignKey(Object)

Author:

Mark Hayes

See Also:

Class Evolution

Field Summary

Fields

Modifier and Type	Field	Description
protected SerialBinding<D>	dataBinding
protected SerialBinding<SK>	indexKeyBinding
protected SerialBinding<PK>	primaryKeyBinding

Constructor Summary

Constructors

Constructor	Description
SerialSerialKeyCreator(ClassCatalog classCatalog, java.lang.Class<PK> primaryKeyClass, java.lang.Class<D> dataClass, java.lang.Class<SK> indexKeyClass)	Creates a serial-serial key creator.
SerialSerialKeyCreator(SerialBinding<PK> primaryKeyBinding, SerialBinding<D> dataBinding, SerialBinding<SK> indexKeyBinding)	Creates a serial-serial entity binding.

Method Summary

Modifier and Type	Method	Description
boolean	createSecondaryKey(SecondaryDatabase db, DatabaseEntry primaryKeyEntry, DatabaseEntry dataEntry, DatabaseEntry indexKeyEntry)	Creates a secondary key entry, given a primary key and data entry.
abstract SK	createSecondaryKey(PK primaryKey, D data)	Creates the index key object from primary key and data objects.
boolean	nullifyForeignKey(SecondaryDatabase db, DatabaseEntry dataEntry)	Sets the foreign key reference to null in the datum of the primary database.
D	nullifyForeignKey(D data)	Clears the index key in a data object.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

primaryKeyBinding

protected SerialBinding<PK> primaryKeyBinding

dataBinding

protected SerialBinding<D> dataBinding

indexKeyBinding

protected SerialBinding<SK> indexKeyBinding

Constructor Detail

SerialSerialKeyCreator

public SerialSerialKeyCreator(ClassCatalog classCatalog,
                              java.lang.Class<PK> primaryKeyClass,
                              java.lang.Class<D> dataClass,
                              java.lang.Class<SK> indexKeyClass)

Creates a serial-serial key creator.

Parameters:

classCatalog - is the catalog to hold shared class information and for a database should be a StoredClassCatalog.

primaryKeyClass - is the primary key base class.

dataClass - is the data base class.

indexKeyClass - is the index key base class.

SerialSerialKeyCreator

public SerialSerialKeyCreator(SerialBinding<PK> primaryKeyBinding,
                              SerialBinding<D> dataBinding,
                              SerialBinding<SK> indexKeyBinding)

Creates a serial-serial entity binding.

Parameters:

primaryKeyBinding - is the primary key binding.

dataBinding - is the data binding.

indexKeyBinding - is the index key binding.

Method Detail

createSecondaryKey

public boolean createSecondaryKey(SecondaryDatabase db,
                                  DatabaseEntry primaryKeyEntry,
                                  DatabaseEntry dataEntry,
                                  DatabaseEntry indexKeyEntry)

Description copied from interface: SecondaryKeyCreator

Creates a secondary key entry, given a primary key and data entry.

A secondary key may be derived from the primary key, primary data, or a combination of the primary key and data. For secondary keys that are optional, the key creator method may return false and the key/data pair will not be indexed. To ensure the integrity of a secondary database the key creator method must always return the same result for a given set of input parameters.

A RuntimeException may be thrown by this method if an error occurs attempting to create the secondary key. This exception will be thrown by the API method currently in progress, for example, a put method. However, this will cause the write operation to be incomplete. When databases are not configured to be transactional, caution should be used to avoid integrity problems. See Special considerations for using Secondary Databases with and without Transactions.

Specified by:

createSecondaryKey in interface SecondaryKeyCreator

Parameters:

db - the database to which the secondary key will be added. This parameter is passed for informational purposes but is not commonly used. This parameter is always non-null.

primaryKeyEntry - the primary key entry. This parameter must not be modified by this method. This parameter is always non-null.

dataEntry - the primary data entry. This parameter must not be modified by this method. If SecondaryConfig.setExtractFromPrimaryKeyOnly(boolean) is configured as true, the data param may be either null or non-null, and the implementation is expected to ignore it; otherwise, this parameter is always non-null.

indexKeyEntry - the secondary key created by this method. This parameter is always non-null.

Returns:

true if a key was created, or false to indicate that the key is not present.

nullifyForeignKey

public boolean nullifyForeignKey(SecondaryDatabase db,
                                 DatabaseEntry dataEntry)

Description copied from interface: ForeignKeyNullifier

Sets the foreign key reference to null in the datum of the primary database.

Specified by:

nullifyForeignKey in interface ForeignKeyNullifier

Parameters:

db - the database in which the foreign key integrity constraint is defined. This parameter is passed for informational purposes but is not commonly used.

dataEntry - the existing primary datum in which the foreign key reference should be set to null. This parameter should be updated by this method if it returns true.

Returns:

true if the datum was modified, or false to indicate that the key is not present.

createSecondaryKey

public abstract SK createSecondaryKey(PK primaryKey,
                                      D data)

Creates the index key object from primary key and data objects.

Parameters:

primaryKey - is the deserialized source primary key entry, or null if no primary key entry is used to construct the index key.

data - is the deserialized source data entry, or null if no data entry is used to construct the index key.

Returns:

the destination index key object, or null to indicate that the key is not present.

nullifyForeignKey

public D nullifyForeignKey(D data)

Clears the index key in a data object.

On entry the data parameter contains the index key to be cleared. It should be changed by this method such that createSecondaryKey(com.sleepycat.je.SecondaryDatabase, com.sleepycat.je.DatabaseEntry, com.sleepycat.je.DatabaseEntry, com.sleepycat.je.DatabaseEntry) will return false. Other fields in the data object should remain unchanged.

Parameters:

data - is the source and destination data object.

Returns:

the destination data object, or null to indicate that the key is not present and no change is necessary. The data returned may be the same object passed as the data parameter or a newly created object.