org.jpox.store.mapped.mapping
Class ReferenceMapping

java.lang.Object
  org.jpox.store.mapped.mapping.JavaTypeMapping
      org.jpox.store.mapped.mapping.MultiMapping
          org.jpox.store.mapped.mapping.ReferenceMapping

All Implemented Interfaces:

MappingCallbacks

Direct Known Subclasses:

InterfaceMapping, ObjectMapping

public abstract class ReferenceMapping
extends MultiMapping
implements MappingCallbacks

Mapping for a reference type. This can be used for things like interfaces, or Object which are simply a reference to some specific (PersistenceCapable) class. All fields of this type have a list of possible "implementations" of the reference type. A column is created for each possible implementation of the reference as a FK to the implementation table.

Version:

$Revision: 1.33 $

Field Summary

Fields inherited from class org.jpox.store.mapped.mapping.MultiMapping

javaTypeMappings

Fields inherited from class org.jpox.store.mapped.mapping.JavaTypeMapping

datastoreContainer, datastoreMappings, dba, fmd, LOCALISER, MAPPING_ARRAY_ELEMENT, MAPPING_COLLECTION_ELEMENT, MAPPING_FIELD, MAPPING_MAP_KEY, MAPPING_MAP_VALUE, referenceMapping, roleForField, type

Constructor Summary

ReferenceMapping()

Method Summary

protected void	createColumns(DatastoreContainerObject datastoreContainer, AbstractMemberMetaData fmd, ClassLoaderResolver clr) Convenience method to create a column for each implementation type of this reference.
java.lang.Class	getJavaType() Accessor for the java type being mapped.
java.lang.Object	getSampleValue(ClassLoaderResolver clr) Return a sample value of the mapping type to be used for internal evaluation of type and conversion.
void	initialize(DatastoreAdapter dba, AbstractMemberMetaData fmd, DatastoreContainerObject container, ClassLoaderResolver clr) Initialize this JavaTypeMapping with the given DatastoreAdapter for the given FieldMetaData.
ScalarExpression	newLiteral(QueryExpression qs, java.lang.Object value) Creates a literal from an value.
ScalarExpression	newScalarExpression(QueryExpression qs, LogicSetExpression te) Creates a expression from a field name/table.
void	postFetch(StateManager sm) Method executed just after a fetch of the owning object, allowing any necessary action to this field and the object stored in it.
void	postInsert(StateManager sm) Method executed just after the insert of the owning object, allowing any necessary action to this field and the object stored in it.
void	postUpdate(StateManager sm) Method executed just afer any update of the owning object, allowing any necessary action to this field and the object stored in it.
void	preDelete(StateManager sm) Method executed just before the owning object is deleted, allowing tidying up of any relation information.

Methods inherited from class org.jpox.store.mapped.mapping.MultiMapping

addJavaTypeMapping, getDataStoreMapping, getJavaTypeMapping, getNumberOfDatastoreFields, getObject, setObject, setObject

Methods inherited from class org.jpox.store.mapped.mapping.JavaTypeMapping

addDataStoreMapping, failureMessage, getBoolean, getByte, getChar, getDatastoreContainer, getDataStoreMappings, getDouble, getFieldMetaData, getFloat, getInt, getJavaTypeForDatastoreMapping, getLong, getObject, getReferenceMapping, getRoleForField, getShort, getString, getType, includeInFetchStatement, includeInInsertStatement, includeInUpdateStatement, initialize, isNullable, isSerialised, setBoolean, setByte, setChar, setDefault, setDouble, setFieldInformation, setFloat, setInt, setLong, setReferenceMapping, setRoleForField, setShort, setString

Methods inherited from class java.lang.Object

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

Constructor Detail

ReferenceMapping

public ReferenceMapping()

Method Detail

initialize

public void initialize(DatastoreAdapter dba,
                       AbstractMemberMetaData fmd,
                       DatastoreContainerObject container,
                       ClassLoaderResolver clr)

Initialize this JavaTypeMapping with the given DatastoreAdapter for the given FieldMetaData.

Overrides:

initialize in class JavaTypeMapping

Parameters:

dba - The Datastore Adapter that this Mapping should use.

fmd - FieldMetaData for the field to be mapped (if any)

container - The datastore container storing this mapping (if any)

clr - the ClassLoaderResolver

createColumns

protected void createColumns(DatastoreContainerObject datastoreContainer,
                             AbstractMemberMetaData fmd,
                             ClassLoaderResolver clr)

Convenience method to create a column for each implementation type of this reference.

Parameters:

datastoreContainer - Table to use

fmd - MetaData for the field

clr - The ClassLoaderResolver

getJavaType

public java.lang.Class getJavaType()

Description copied from class: JavaTypeMapping

Accessor for the java type being mapped. This is the java type that the mapping represents. Some examples :

• if the field is of type "MyClass" then the mapping will be OIDMapping (or subclass) the javaType will be OID, and the type will be MyClass.
• if the field is of type "int" then the mapping will be IntegerMapping, the javaType will be Integer, and the type will be int.

The "java type" is the java-type name used in the plugin.xml mapping file

Specified by:

getJavaType in class JavaTypeMapping

Returns:

The java type

getSampleValue

public java.lang.Object getSampleValue(ClassLoaderResolver clr)

Description copied from class: JavaTypeMapping

Return a sample value of the mapping type to be used for internal evaluation of type and conversion.

Specified by:

getSampleValue in class JavaTypeMapping

Parameters:

clr - TODO

Returns:

The sample value.

newLiteral

public ScalarExpression newLiteral(QueryExpression qs,
                                   java.lang.Object value)

Description copied from class: JavaTypeMapping

Creates a literal from an value. A string literal is enclosed in single quotes. for example: "literal". A string literal that includes a single quote is represented by two single quotes. for example: "literal''s". An exact numeric literal is a numeric value without a decimal point, such as 57, -957, +62. An approximate numeric literal is a numeric value in scientific notation, such as 7E3, -57.9E2, or a numeric value with a decimal, such as 7., -95.7, +6.2.

Specified by:

newLiteral in class JavaTypeMapping

Parameters:

qs - The Query statement

value - The object

Returns:

A Scalar Expression

newScalarExpression

public ScalarExpression newScalarExpression(QueryExpression qs,
                                            LogicSetExpression te)

Description copied from class: JavaTypeMapping

Creates a expression from a field name/table. e.g. tablename.fieldname; tablealias.fieldalias

Specified by:

newScalarExpression in class JavaTypeMapping

Parameters:

qs - The Query statement

te - the alias for the table

Returns:

A Scalar Expression

postFetch

public void postFetch(StateManager sm)

Method executed just after a fetch of the owning object, allowing any necessary action to this field and the object stored in it.

Specified by:

postFetch in interface MappingCallbacks

Parameters:

sm - StateManager for the owner.

postInsert

public void postInsert(StateManager sm)

Method executed just after the insert of the owning object, allowing any necessary action to this field and the object stored in it.

Specified by:

postInsert in interface MappingCallbacks

Parameters:

sm - StateManager for the owner

postUpdate

public void postUpdate(StateManager sm)

Method executed just afer any update of the owning object, allowing any necessary action to this field and the object stored in it.

Specified by:

postUpdate in interface MappingCallbacks

Parameters:

sm - StateManager for the owner

preDelete

public void preDelete(StateManager sm)

Method executed just before the owning object is deleted, allowing tidying up of any relation information.

Specified by:

preDelete in interface MappingCallbacks

Parameters:

sm - StateManager for the owner