org.melati.poem
Class StandardIntegrityFix

java.lang.Object
  org.melati.poem.StandardIntegrityFix

All Implemented Interfaces:

IntegrityFix

public abstract class StandardIntegrityFix
extends Object
implements IntegrityFix

A class which defines the three standard integrity fixes of delete, clear and prevent.

These correspond to the SQL ON DELETE CASCADE, ON DELETE SET NULL and ON DELETE NO ACTION.

Nested Class Summary

static class

StandardIntegrityFix.NameUnrecognisedException Thrown when an invalid StandardIntegrityFix is specified, by a typing mistake in the DSD for example.

Field Summary

static StandardIntegrityFix	clear Clear (make null) field in referring object.
static StandardIntegrityFix	delete Delete referred objects.
static StandardIntegrityFix	prevent Disallow the deletion.

Method Summary

static int	count()
static StandardIntegrityFix	forIndex(int i) Get a fix by its index.
Integer	getIndex()
String	getName() Integrity fixes are set in the DSD by name.
static StandardIntegrityFix	named(String name) Find by name.
abstract Enumeration	referencesTo(Persistent referee, Column column, Enumeration refs, Map referenceFixOfColumn) Each StandardIntegrityFix differs from another by the way they implement referencesTo(org.melati.poem.Persistent, org.melati.poem.Column, java.util.Enumeration, java.util.Map).
String	toString() Return the name and index.

Methods inherited from class java.lang.Object

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

Field Detail

delete

public static final StandardIntegrityFix delete

Delete referred objects.

clear

public static final StandardIntegrityFix clear

Clear (make null) field in referring object.

prevent

public static final StandardIntegrityFix prevent

Disallow the deletion.

Method Detail

getName

public String getName()

Description copied from interface: IntegrityFix

Integrity fixes are set in the DSD by name.

Specified by:

getName in interface IntegrityFix

Returns:

the name

getIndex

public Integer getIndex()

Returns:

the index.

referencesTo

public abstract Enumeration referencesTo(Persistent referee,
                                         Column column,
                                         Enumeration refs,
                                         Map referenceFixOfColumn)

Each StandardIntegrityFix differs from another by the way they implement referencesTo(org.melati.poem.Persistent, org.melati.poem.Column, java.util.Enumeration, java.util.Map). delete deletes all references to this Persistent.
clear sets the references to null.
prevent returns the references, which prevokes an exception

Specified by:

referencesTo in interface IntegrityFix

Parameters:

referee - the Persistent we are deleting

column - the Column of the reference to Persistent we are deleting, used in clear

refs - an Enumeration of the objects which contain a reference to the Persistent we are deleting, each is deleted, cleared or returned respectively

referenceFixOfColumn - a Map keyed on Column giving the associated IntegrityFix, passed in to the Persistent referer to delete itself

Returns:

an Enumeration of the remaining referers, which if not empty will prevent deletion

See Also:

Persistent.delete(Map)

forIndex

public static StandardIntegrityFix forIndex(int i)

Get a fix by its index.

Parameters:

i - the index

Returns:

the fix at that index

count

public static int count()

Returns:

the number of fixes

named

public static StandardIntegrityFix named(String name)

Find by name.

Parameters:

name - the name

Returns:

the named fix

toString

public String toString()

Return the name and index.

Overrides:

toString in class Object

See Also:

Object.toString()