com.db4o.internal

Class Config4Class

java.lang.Object

com.db4o.internal.Config4Abstract

com.db4o.internal.Config4Class

All Implemented Interfaces:

ObjectClass, DeepClone

public class Config4Class
extends Config4Abstract
implements ObjectClass, DeepClone

Field Summary

Fields inherited from class com.db4o.internal.Config4Abstract

_config

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Config4Class(Config4Impl configuration, KeySpecHashtable4 config)

Method Summary

Methods

Modifier and Type	Method and Description
int	adjustActivationDepth(int depth)
TernaryBool	callConstructor()
void	callConstructor(boolean flag) advises db4o to try instantiating objects of this class with/without calling constructors.
void	compare(ObjectAttribute comparator) Deprecated.
java.lang.Object	deepClone(java.lang.Object param) The parameter allows passing one new object so parent references can be corrected on children.
void	enableReplication(boolean setting) Must be called before databases are created or opened so that db4o will control versions and generate UUIDs for objects of this class, which is required for using replication.
void	generateUUIDs(boolean setting) generate UUIDs for stored objects of this class.
void	generateVersionNumbers(boolean setting) generate version numbers for stored objects of this class.
ObjectTranslator	getTranslator()
boolean	indexed()
void	indexed(boolean flag) turns the class index on or off.
void	maximumActivationDepth(int depth) sets the maximum activation depth to the desired value.
int	minimumActivationDepth() gets the configured minimum activation depth.
void	minimumActivationDepth(int depth) sets the minimum activation depth to the desired value.
ObjectField	objectField(java.lang.String fieldName) returns an ObjectField object to configure the specified field.
void	persistStaticFieldValues() turns on storing static field values for this class.
ObjectAttribute	queryAttributeProvider()
void	rename(java.lang.String newName) renames a stored class.
boolean	storeTransientFields()
void	storeTransientFields(boolean flag) allows to specify if transient fields are to be stored.
void	translate(ObjectTranslator translator) registers a translator for this class.
void	updateDepth(int depth) specifies the updateDepth for this class.

Methods inherited from class com.db4o.internal.Config4Abstract

cascadeOnActivate, cascadeOnActivate, cascadeOnDelete, cascadeOnDelete, cascadeOnUpdate, cascadeOnUpdate, equals, getName, hashCode, putThreeValued, putThreeValuedInt, setName

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.db4o.config.ObjectClass

cascadeOnActivate, cascadeOnDelete, cascadeOnUpdate

Constructor Detail

Config4Class

protected Config4Class(Config4Impl configuration,
            KeySpecHashtable4 config)

Method Detail

adjustActivationDepth

public int adjustActivationDepth(int depth)

callConstructor

public void callConstructor(boolean flag)

Description copied from interface: ObjectClass

advises db4o to try instantiating objects of this class with/without calling constructors.

Not all JDKs / .NET-environments support this feature. db4o will attempt, to follow the setting as good as the environment supports. In doing so, it may call implementation-specific features like sun.reflect.ReflectionFactory#newConstructorForSerialization on the Sun Java 1.4.x/5 VM (not available on other VMs) and FormatterServices.GetUninitializedObject() on the .NET framework (not available on CompactFramework).

This setting may also be set globally for all classes in Configuration.callConstructors(boolean).

In client-server environment this setting should be used on both client and server.

This setting can be applied to an open object container.

Specified by:

callConstructor in interface ObjectClass

Parameters:

flag - - specify true, to request calling constructors, specify false to request not calling constructors.

See Also:

Configuration.callConstructors(boolean)

compare

public void compare(ObjectAttribute comparator)

Deprecated.

Description copied from interface: ObjectClass

registers an attribute provider for special query behavior.

The query processor will compare the object returned by the attribute provider instead of the actual object, both for the constraint and the candidate persistent object.

In client-server environment this setting should be used on both client and server.

Specified by:

compare in interface ObjectClass

Parameters:

comparator - the attribute provider to be used

deepClone

public java.lang.Object deepClone(java.lang.Object param)

Description copied from interface: DeepClone

The parameter allows passing one new object so parent references can be corrected on children.

Specified by:

deepClone in interface DeepClone

enableReplication

public void enableReplication(boolean setting)

Description copied from interface: ObjectClass

Must be called before databases are created or opened so that db4o will control versions and generate UUIDs for objects of this class, which is required for using replication.

Specified by:

enableReplication in interface ObjectClass

generateUUIDs

public void generateUUIDs(boolean setting)

Description copied from interface: ObjectClass

generate UUIDs for stored objects of this class. This setting should be used before the database is first created.

Specified by:

generateUUIDs in interface ObjectClass

generateVersionNumbers

public void generateVersionNumbers(boolean setting)

Description copied from interface: ObjectClass

generate version numbers for stored objects of this class. This setting should be used before the database is first created.

Specified by:

generateVersionNumbers in interface ObjectClass

getTranslator

public ObjectTranslator getTranslator()

indexed

public void indexed(boolean flag)

Description copied from interface: ObjectClass

turns the class index on or off.

db4o maintains an index for each class to be able to deliver all instances of a class in a query. If the class index is never needed, it can be turned off with this method to improve the performance to create and delete objects of a class.

Common cases where a class index is not needed:
- The application always works with sub classes or super classes.
- There are convenient field indexes that will always find instances of a class.
- The application always works with IDs.

In client-server environment this setting should be used on both client and server.

This setting can be applied to an open object container.

Specified by:

indexed in interface ObjectClass

indexed

public boolean indexed()

maximumActivationDepth

public void maximumActivationDepth(int depth)

Description copied from interface: ObjectClass

sets the maximum activation depth to the desired value.

A class specific setting overrides the global setting

In client-server environment this setting should be used on both client and server.

This setting can be applied to an open object container.

Specified by:

maximumActivationDepth in interface ObjectClass

Parameters:

depth - the desired maximum activation depth

See Also:

Why activation?, ObjectClass.cascadeOnActivate(boolean)

minimumActivationDepth

public void minimumActivationDepth(int depth)

Description copied from interface: ObjectClass

sets the minimum activation depth to the desired value.

A class specific setting overrides the global setting

In client-server environment this setting should be used on both client and server.

This setting can be applied to an open object container.

Specified by:

minimumActivationDepth in interface ObjectClass

Parameters:

depth - the desired minimum activation depth

See Also:

Why activation?, ObjectClass.cascadeOnActivate(boolean)

minimumActivationDepth

public int minimumActivationDepth()

Description copied from interface: ObjectClass

gets the configured minimum activation depth. In client-server environment this setting should be used on both client and server.

Specified by:

minimumActivationDepth in interface ObjectClass

Returns:

the configured minimum activation depth.

callConstructor

public TernaryBool callConstructor()

objectField

public ObjectField objectField(java.lang.String fieldName)

Description copied from interface: ObjectClass

returns an ObjectField object to configure the specified field.

Specified by:

objectField in interface ObjectClass

Parameters:

fieldName - the name of the field to be configured.

Returns:

an instance of an ObjectField object for configuration.

persistStaticFieldValues

public void persistStaticFieldValues()

Description copied from interface: ObjectClass

turns on storing static field values for this class.

By default, static field values of classes are not stored to the database file. By turning the setting on for a specific class with this switch, all non-simple-typed static field values of this class are stored the first time an object of the class is stored, and restored, every time a database file is opened afterwards, after class meta information is loaded for this class (which can happen by querying for a class or by loading an instance of a class).

To update a static field value, once it is stored, you have to the following in this order:
(1) open the database file you are working against
(2) make sure the class metadata is loaded
objectContainer.query().constrain(Foo.class); // Java
objectContainer.Query().Constrain(typeof(Foo)); // C#
(3) change the static member
(4) store the static member explicitly
objectContainer.store(Foo.staticMember); // Java

The setting will be ignored for simple types.

Use this setting for constant static object members.

This option will slow down the process of opening database files and the stored objects will occupy space in the database file.

In client-server environment this setting should be used on both client and server.

This setting can NOT be applied to an open object container.

Specified by:

persistStaticFieldValues in interface ObjectClass

rename

public void rename(java.lang.String newName)

Description copied from interface: ObjectClass

renames a stored class.

Use this method to refactor classes.

In client-server environment this setting should be used on both client and server.

This setting can NOT be applied to an open object container.

Specified by:

rename in interface ObjectClass

Parameters:

newName - the new fully qualified class name.

storeTransientFields

public void storeTransientFields(boolean flag)

Description copied from interface: ObjectClass

allows to specify if transient fields are to be stored.
The default for every class is false.

In client-server environment this setting should be used on both client and server.

This setting can be applied to an open object container.

Specified by:

storeTransientFields in interface ObjectClass

Parameters:

flag - whether or not transient fields are to be stored.

translate

public void translate(ObjectTranslator translator)

Description copied from interface: ObjectClass

registers a translator for this class.



The use of an ObjectTranslator is not compatible with the use of an internal class ObjectMarshaller.

In client-server environment this setting should be used on both client and server.

This setting can be applied to an open object container.

Specified by:

translate in interface ObjectClass

Parameters:

translator - this may be an ObjectTranslator or an ObjectConstructor

See Also:

ObjectTranslator, ObjectConstructor

updateDepth

public void updateDepth(int depth)

Description copied from interface: ObjectClass

specifies the updateDepth for this class.

see the documentation of ObjectContainer.store(Object) for further details.

The default setting is 0: Only the object passed to ObjectContainer.store(Object) will be updated.

In client-server environment this setting should be used on both client and server.

Specified by:

updateDepth in interface ObjectClass

Parameters:

depth - the depth of the desired update for this class.

See Also:

Configuration.updateDepth(int), ObjectClass.cascadeOnUpdate(boolean), ObjectField.cascadeOnUpdate(boolean), Using callbacks

queryAttributeProvider

public ObjectAttribute queryAttributeProvider()

storeTransientFields

public boolean storeTransientFields()