com.ashridgetech.prevdb.client
Class FieldMap

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

public final class FieldMap

extends Object

A mapping from a set of a persistent fields of one Persistent class to their values, in one Persistent object. Can be used with the Persistent interface to get or set fields. Field values cannot be removed once set, but they can be set more than once (although this is not recommended). The fields are stored in the order in which they are set by calls to setFieldValue(com.ashridgetech.prevdb.client.PersistentField, java.lang.Object).

Version:

1.0

Author:

paulb

Constructor Summary

FieldMap(Class persistentClass, Object oid)
Creates a new FieldMap for a particular persistent class and oid.

FieldMap(Persistent obj)
Creates a new FieldMap for a particular persistent object.

Method Summary

Set	getFields() Get the set of fields in this FieldMap, in the order in which they were set.
Object	getFieldValue(PersistentField field) Get a field value that is known to be held in this FieldMap
Object	getOid() Get the oid
Class	getPersistentClass() Get the class to which this FieldMap belongs
boolean	hasFieldValue(PersistentField field) Indicate whether this FieldMap has a value for a particular field
boolean	isMapFor(Persistent obj) Show whether this FieldMap holds field values for a given Persistent object.
void	setFieldValue(PersistentField field, Object value) Set a field value in this FieldMap
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

FieldMap

public FieldMap(Class persistentClass,
                Object oid)

Creates a new FieldMap for a particular persistent class and oid.

Parameters:

persistentClass - the class of object for which this FieldMap stores fields and values

oid - the object id of the Persistent to which the field values in this FieldMap apply

FieldMap

public FieldMap(Persistent obj)

Creates a new FieldMap for a particular persistent object.

Parameters:

obj - the object for which this FieldMap stores fields and values

Method Detail

getPersistentClass

public Class getPersistentClass()

Get the class to which this FieldMap belongs

Returns:

the class to which this FieldMap belongs

getOid

public Object getOid()

Get the oid

Returns:

the object id of the Persistent to which the field values in this FieldMap apply

isMapFor

public boolean isMapFor(Persistent obj)

Show whether this FieldMap holds field values for a given Persistent object.

Parameters:

obj - the persistent object to check

getFieldValue

public Object getFieldValue(PersistentField field)

Get a field value that is known to be held in this FieldMap

Parameters:

field - the field for which a value is required

Returns:

the value of the field

See Also:

hasFieldValue(com.ashridgetech.prevdb.client.PersistentField)

setFieldValue

public void setFieldValue(PersistentField field,
                          Object value)

Set a field value in this FieldMap

Parameters:

field - the field for which a value is to be set

Returns:

the name of the field

See Also:

getFieldValue(com.ashridgetech.prevdb.client.PersistentField)

hasFieldValue

public boolean hasFieldValue(PersistentField field)

Indicate whether this FieldMap has a value for a particular field

Parameters:

field - the field for which a value is required

Returns:

true if this FieldMap has a value for field

getFields

public Set getFields()

Get the set of fields in this FieldMap, in the order in which they were set.

Returns:

the unmodifiable set of PersistentField objects

toString

public String toString()

Overrides:

toString in class Object