com.ashridgetech.prevdb.client
Class AbstractPersistentObject

java.lang.Object
  |
  +--com.ashridgetech.prevdb.client.AbstractPersistentObject

All Implemented Interfaces:

Persistent

Direct Known Subclasses:

TestClassA, TestClassB, TestClassC

public abstract class AbstractPersistentObject

extends Object

implements Persistent

A convenient base class for classes that want to implement Persistent. Holds an oid. Cooperates with its PersistentManager.

Version:

1.0

Author:

paulb

Field Summary

Object	oid
static PersistentField	OID
protected static PersistentField[]	PERSISTENT_FIELDS

Constructor Summary

protected	AbstractPersistentObject(PersistentManager manager)
protected	AbstractPersistentObject(PersistentManager manager, Object oid)
protected	AbstractPersistentObject(PrevDb prevDb, Class thisClass)

Method Summary

Object	getField(PersistentField field) Get the value of a single field.
FieldMap	getFields() Get a map of all the persistent fields in this object.
protected Object	getJavaField(Field javaField) Get the value of a Java field.
PersistentManager	getManager() Get the PersistentManager for this class
Object	getOid() Get the oid of this object.
static PersistentField	getPersistentField(PersistentField[] persistentFields, String name) Get a PersistentField from an array by name.
protected PersistentField[]	getPersistentFields() Provide an array of PersistentFields for this object.
protected int	notifyUpdate(PersistentField field, int oldValue, int newValue)
protected Object	notifyUpdate(PersistentField field, Object oldValue, Object newValue) Convenience method to allow a subclass setter method to call PersistentManager.notifyFieldUpdate(com.ashridgetech.prevdb.client.Persistent, com.ashridgetech.prevdb.client.PersistentField, java.lang.Object, java.lang.Object).
protected String	notifyUpdate(PersistentField field, String oldValue, String newValue)
void	setField(PersistentField field, Object value) Set the value of a single field.
void	setFields(FieldMap fields) Set some or all of the fields in this object.
protected void	setJavaField(Field javaField, Object value) Set the value of a Java field.

Methods inherited from class java.lang.Object

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

Field Detail

oid

public Object oid

OID

public static final PersistentField OID

PERSISTENT_FIELDS

protected static final PersistentField[] PERSISTENT_FIELDS

Constructor Detail

AbstractPersistentObject

protected AbstractPersistentObject(PersistentManager manager,
                                   Object oid)

AbstractPersistentObject

protected AbstractPersistentObject(PersistentManager manager)

AbstractPersistentObject

protected AbstractPersistentObject(PrevDb prevDb,
                                   Class thisClass)

Method Detail

getOid

public Object getOid()

Description copied from interface: Persistent

Get the oid of this object. This is the unique identifier for objects of this object's class.

Specified by:

getOid in interface Persistent

Returns:

the oid

getManager

public PersistentManager getManager()

Get the PersistentManager for this class

Specified by:

getManager in interface Persistent

Returns:

the PersistentManager

getFields

public FieldMap getFields()

Description copied from interface: Persistent

Get a map of all the persistent fields in this object.

Specified by:

getFields in interface Persistent

Returns:

the field map

setFields

public void setFields(FieldMap fields)

Description copied from interface: Persistent

Set some or all of the fields in this object.

Specified by:

setFields in interface Persistent

Parameters:

fields - the fields to set

getField

public Object getField(PersistentField field)

Description copied from interface: Persistent

Get the value of a single field.

Specified by:

getField in interface Persistent

Parameters:

field - the PersistentFieldwhose value is required

Returns:

the field value

setField

public void setField(PersistentField field,
                     Object value)

Description copied from interface: Persistent

Set the value of a single field.

Specified by:

setField in interface Persistent

Parameters:

field - the PersistentFieldwhose value is to be set

value - the field value

notifyUpdate

protected Object notifyUpdate(PersistentField field,
                              Object oldValue,
                              Object newValue)

Convenience method to allow a subclass setter method to call PersistentManager.notifyFieldUpdate(com.ashridgetech.prevdb.client.Persistent, com.ashridgetech.prevdb.client.PersistentField, java.lang.Object, java.lang.Object). Returns the new value so that the notification and assignment can be done in one line eg

    public void setBalance( BigDecimal balance ) {
        this.balance = noyifyUpdate( this.balance, balance );
    }
 

Parameters:

field - the persistent field being updated

oldValue - the existing value of the field

newValue - the new value of the field

Returns:

the new value

notifyUpdate

protected String notifyUpdate(PersistentField field,
                              String oldValue,
                              String newValue)

See Also:

notifyUpdate( PersistentField, Object, Object )

notifyUpdate

protected int notifyUpdate(PersistentField field,
                           int oldValue,
                           int newValue)

See Also:

notifyUpdate( PersistentField, Object, Object )

getJavaField

protected Object getJavaField(Field javaField)
                       throws IllegalAccessException

Get the value of a Java field. Must be duplicated in each subclass to avoid access restrictions. The code required is simply return javaField.get( this );

Parameters:

javaField - the Field to get the value of

Returns:

the value

IllegalAccessException

setJavaField

protected void setJavaField(Field javaField,
                            Object value)
                     throws IllegalAccessException

Set the value of a Java field. Must be duplicated in each subclass to avoid access restrictions. The code required is simply javaField.set( this, value );

Parameters:

javaField - the Field to set the value of

value - the value to set

IllegalAccessException

getPersistentFields

protected PersistentField[] getPersistentFields()

Provide an array of PersistentFields for this object. Must include the persistent fields of the superclass, if any

Returns:

the array of PersistentFields

getPersistentField

public static PersistentField getPersistentField(PersistentField[] persistentFields,
                                                 String name)

Get a PersistentField from an array by name.

Parameters:

persistentFields - the fields to select from

name - the name of the field

Returns:

the field

Throws:

IllegalArgumentException - if no field called name exists in persistentFields