org.jpox.state
Class RelationshipManager

java.lang.Object
  org.jpox.state.RelationshipManager

public class RelationshipManager
extends java.lang.Object

Manager for relationships of a class. Performs management of (bidirectional) relations. If one side is set yet the other isnt, corrects the other side.

Version:

$Revision$

Field Summary

protected static Localiser

LOCALISER Localiser for messages.

Constructor Summary

RelationshipManager(StateManager sm)
Constructor.

Method Summary

void	checkConsistency() Method to check for consistency the managed relations of this object with the related objects.
protected void	checkManyToManyBidirectionalRelation(AbstractMemberMetaData mmd, ClassLoaderResolver clr, ObjectManager om, java.util.ArrayList changes) Method to check consistency of the passed field as M-N.
protected void	checkManyToOneBidirectionalRelation(AbstractMemberMetaData mmd, ClassLoaderResolver clr, ObjectManager om, java.lang.Object oldValue, java.lang.Object newValue) Method to check the consistency of the passed field as N-1.
protected void	checkOneToManyBidirectionalRelation(AbstractMemberMetaData mmd, ClassLoaderResolver clr, ObjectManager om, java.util.ArrayList changes) Method to check the consistency of the passed field as 1-N.
protected void	checkOneToOneBidirectionalRelation(AbstractMemberMetaData mmd, ClassLoaderResolver clr, ObjectManager om, java.lang.Object oldValue, java.lang.Object newValue) Method to check the consistency of the passed field as 1-1.
void	clearFields() Convenience method to clear all fields from being managed.
void	process() Method to process the (bidirectional) relations for this object.
protected void	processManyToManyBidirectionalRelation(AbstractMemberMetaData mmd, ClassLoaderResolver clr, ObjectManager om, java.util.ArrayList changes) Method to process all M-N bidir fields.
protected void	processManyToOneBidirectionalRelation(AbstractMemberMetaData mmd, ClassLoaderResolver clr, ObjectManager om, java.lang.Object oldValue, java.lang.Object newValue) Method to process all N-1 bidir fields.
protected void	processOneToManyBidirectionalRelation(AbstractMemberMetaData mmd, ClassLoaderResolver clr, ObjectManager om, java.util.ArrayList changes) Method to process all 1-N bidir fields.
protected void	processOneToOneBidirectionalRelation(AbstractMemberMetaData mmd, ClassLoaderResolver clr, ObjectManager om, java.lang.Object oldValue, java.lang.Object newValue) Method to process all 1-1 bidir fields.
void	relationAdd(int fieldNumber, java.lang.Object val) Method to register a change in the contents of a container field, with an object being added.
void	relationChange(int fieldNumber, java.lang.Object oldValue, java.lang.Object newValue) Method that is called when the user calls setXXX() on a field.
void	relationRemove(int fieldNumber, java.lang.Object val) Method to register a change in the contents of a container field, with an object being removed.

Methods inherited from class java.lang.Object

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

Field Detail

LOCALISER

protected static final Localiser LOCALISER

Localiser for messages.

Constructor Detail

RelationshipManager

public RelationshipManager(StateManager sm)

Constructor.

Parameters:

sm - StateManager for the object that we are managing relations for.

Method Detail

clearFields

public void clearFields()

Convenience method to clear all fields from being managed.

relationChange

public void relationChange(int fieldNumber,
                           java.lang.Object oldValue,
                           java.lang.Object newValue)

Method that is called when the user calls setXXX() on a field.

Parameters:

fieldNumber - Number of the field

oldValue - The old value

newValue - The new value

relationAdd

public void relationAdd(int fieldNumber,
                        java.lang.Object val)

Method to register a change in the contents of a container field, with an object being added.

Parameters:

fieldNumber - Number of the field

val - Value being added

relationRemove

public void relationRemove(int fieldNumber,
                           java.lang.Object val)

Method to register a change in the contents of a container field, with an object being removed.

Parameters:

fieldNumber - Number of the field

val - Value being removed

checkConsistency

public void checkConsistency()

Method to check for consistency the managed relations of this object with the related objects.

process

public void process()

Method to process the (bidirectional) relations for this object.

checkOneToOneBidirectionalRelation

protected void checkOneToOneBidirectionalRelation(AbstractMemberMetaData mmd,
                                                  ClassLoaderResolver clr,
                                                  ObjectManager om,
                                                  java.lang.Object oldValue,
                                                  java.lang.Object newValue)

Method to check the consistency of the passed field as 1-1. Processes the case where we had a 1-1 field set at this side previously to some value and now to some other value. We need to make sure that all of the affected objects are now related consistently. Taking an example

a.b = b1; a.b = b2;

so A's b field is changed from b1 to b2. The following changes are likely to be necessary

• b1.a = null - so we null out the old related objects link back to this object
• b2.oldA = null - if b2 was previously related to a different A, null out that objects link to b2
• b2.a = a - set the link from b2 back to a so it is bidirectional

Parameters:

mmd - MetaData for the field

clr - ClassLoader resolver

om - ObjectManager

oldValue - The old value

newValue - The new value

checkOneToManyBidirectionalRelation

protected void checkOneToManyBidirectionalRelation(AbstractMemberMetaData mmd,
                                                   ClassLoaderResolver clr,
                                                   ObjectManager om,
                                                   java.util.ArrayList changes)

Method to check the consistency of the passed field as 1-N.

Parameters:

mmd - MetaData for the field

clr - ClassLoader resolver

om - ObjectManager

changes - List of changes to the collection

checkManyToOneBidirectionalRelation

protected void checkManyToOneBidirectionalRelation(AbstractMemberMetaData mmd,
                                                   ClassLoaderResolver clr,
                                                   ObjectManager om,
                                                   java.lang.Object oldValue,
                                                   java.lang.Object newValue)

Method to check the consistency of the passed field as N-1. Processes the case where we had an N-1 field set at this side previously to some value and now to some other value.That is, this object was in some collection/map originally, and now should be in some other collection/map. So in terms of an example this object "a" was in collection "b1.as" before and is now in "b2.as". The following changes are likely to be necessary

• b1.getAs().remove(a) - remove it from b1.as if still present
• b2.getAs().add(a) - add it to b1.as if not present

Parameters:

mmd - MetaData for the field

clr - ClassLoader resolver

om - ObjectManager

oldValue - The old value

newValue - The new value

checkManyToManyBidirectionalRelation

protected void checkManyToManyBidirectionalRelation(AbstractMemberMetaData mmd,
                                                    ClassLoaderResolver clr,
                                                    ObjectManager om,
                                                    java.util.ArrayList changes)

Method to check consistency of the passed field as M-N.

Parameters:

mmd - MetaData for the field

clr - ClassLoader resolver

om - ObjectManager

changes - List of changes to the collection

processOneToOneBidirectionalRelation

protected void processOneToOneBidirectionalRelation(AbstractMemberMetaData mmd,
                                                    ClassLoaderResolver clr,
                                                    ObjectManager om,
                                                    java.lang.Object oldValue,
                                                    java.lang.Object newValue)

Method to process all 1-1 bidir fields. Processes the case where we had a 1-1 field set at this side previously to some value and now to some other value. We need to make sure that all of the affected objects are now related consistently. Taking an example

a.b = b1; a.b = b2;

so A's b field is changed from b1 to b2. The following changes are likely to be necessary

• b1.a = null - so we null out the old related objects link back to this object
• b2.oldA = null - if b2 was previously related to a different A, null out that objects link to b2
• b2.a = a - set the link from b2 back to a so it is bidirectional

Parameters:

mmd - MetaData for the field

clr - ClassLoader resolver

om - ObjectManager

oldValue - The old value

newValue - The new value

processOneToManyBidirectionalRelation

protected void processOneToManyBidirectionalRelation(AbstractMemberMetaData mmd,
                                                     ClassLoaderResolver clr,
                                                     ObjectManager om,
                                                     java.util.ArrayList changes)

Method to process all 1-N bidir fields.

Parameters:

mmd - MetaData for the field

clr - ClassLoader resolver

om - ObjectManager

changes - List of changes to the collection

processManyToOneBidirectionalRelation

protected void processManyToOneBidirectionalRelation(AbstractMemberMetaData mmd,
                                                     ClassLoaderResolver clr,
                                                     ObjectManager om,
                                                     java.lang.Object oldValue,
                                                     java.lang.Object newValue)

Method to process all N-1 bidir fields. Processes the case where we had an N-1 field set at this side previously to some value and now to some other value.That is, this object was in some collection/map originally, and now should be in some other collection/map. So in terms of an example this object "a" was in collection "b1.as" before and is now in "b2.as". The following changes are likely to be necessary

• b1.getAs().remove(a) - remove it from b1.as if still present
• b2.getAs().add(a) - add it to b1.as if not present

Parameters:

mmd - MetaData for the field

clr - ClassLoader resolver

om - ObjectManager

oldValue - The old value

newValue - The new value

processManyToManyBidirectionalRelation

protected void processManyToManyBidirectionalRelation(AbstractMemberMetaData mmd,
                                                      ClassLoaderResolver clr,
                                                      ObjectManager om,
                                                      java.util.ArrayList changes)

Method to process all M-N bidir fields.

Parameters:

mmd - MetaData for the field

clr - ClassLoader resolver

om - ObjectManager

changes - List of changes to the collection