Package org.apache.openjpa.jdbc.meta

Class Discriminator

java.lang.Object

org.apache.openjpa.jdbc.meta.Discriminator

All Implemented Interfaces:

Serializable, DiscriminatorStrategy, Strategy, MetaDataContext, MetaDataModes

public class Discriminator
extends Object
implements DiscriminatorStrategy, MetaDataContext, MetaDataModes

Handles determining the object class of database records.

Author:

Abe White

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static final Object	NULL	Null discriminator value marker.

Fields inherited from interface org.apache.openjpa.meta.MetaDataModes

MODE_ALL, MODE_ANN_MAPPING, MODE_MAPPING, MODE_MAPPING_INIT, MODE_META, MODE_NONE, MODE_QUERY

Constructor Summary

Constructors

Constructor	Description
Discriminator(ClassMapping mapping)	Constructor.

Method Summary

Modifier and Type	Method	Description
boolean	addClassConditions(Select sel, boolean subs, Joins joins)	Add WHERE conditions to the given select limiting the returned results to our mapping type, possibly including subclasses.
void	clearMapping()	Clear mapping information, including strategy.
void	customDelete(OpenJPAStateManager sm, JDBCStore store)	Override this method to customize flushing this mapping.
void	customInsert(OpenJPAStateManager sm, JDBCStore store)	Override this method to customize flushing this mapping.
void	customUpdate(OpenJPAStateManager sm, JDBCStore store)	Override this method to customize flushing this mapping.
void	delete(OpenJPAStateManager sm, JDBCStore store, RowManager rm)	Set the where values appropriately to delete the proper instance, and set all relations on non-secondary tables as updates.
String	getAlias()	Return the alias of this strategy.
Class<?>	getClass(JDBCStore store, ClassMapping base, Result result)	Return the class for the current result row.
SQLBuffer	getClassConditions(Select sel, Joins joins, ClassMapping base, boolean subs)	Return SQL to limit the classes selected as much as possible to the given base class, and optionally its subclasses.
ClassMapping	getClassMapping()	Return the owning mapping.
ColumnIO	getColumnIO()	I/O information on the discriminator columns.
Column[]	getColumns()	Columns used by this Discriminator.
Index	getIndex()	Index on the Discriminator columns, or null if none.
int	getJavaType()
DiscriminatorMappingInfo	getMappingInfo()	Raw mapping data.
MappingRepository	getMappingRepository()
MetaDataRepository	getRepository()	Access metadata repository.
int	getResolve()	Resolve mode.
DiscriminatorStrategy	getStrategy()	The strategy used for class discrimination.
boolean	getSubclassesLoaded()	Whether this Discriminator has loaded subclasses yet.
Object	getValue()	The discriminator value.
boolean	hasClassConditions(ClassMapping base, boolean subs)	Whether any class conditions are necessary.
void	initialize()	Perform caching and other initialization operations.
void	insert(OpenJPAStateManager sm, JDBCStore store, RowManager rm)	Set values for the mapping into the proper rows.
Boolean	isCustomDelete(OpenJPAStateManager sm, JDBCStore store)	Return Boolean.FALSE if this mapping does not customize the delete process, Boolean.TRUE if it does, or null if it does customize the delete, but also relies on the standard delete method being called.
Boolean	isCustomInsert(OpenJPAStateManager sm, JDBCStore store)	Return Boolean.FALSE if this mapping does not customize the insert process, Boolean.TRUE if it does, or null if it does customize the insert, but also relies on the standard insert method being called.
Boolean	isCustomUpdate(OpenJPAStateManager sm, JDBCStore store)	Return Boolean.FALSE if this mapping does not customize the update process, Boolean.TRUE if it does, or null if it does customize the update, but also relies on the standard update method being called.
void	loadSubclasses(JDBCStore store)	Load all subclasses of the owning class mapping into the JVM.
void	map(boolean adapt)	Map the owning mapping using this strategy.
void	refSchemaComponents()	Increment the reference count of used schema components.
boolean	resolve(int mode)	Resolve mapping information.
boolean	select(Select sel, ClassMapping mapping)	Select the data for this Discriminator.
void	setColumnIO(ColumnIO io)	I/O information on the discriminator columns.
void	setColumns(Column[] cols)	Columns used by this Discriminator.
void	setDiscriminator(Discriminator owner)	Set the Discriminator that uses this strategy.
void	setIndex(Index idx)	Index on the Discriminator columns, or null if none.
void	setJavaType(int javaType)
void	setResolve(int mode)	Resolve mode.
void	setResolve(int mode, boolean on)	Resolve mode.
void	setStrategy(DiscriminatorStrategy strategy, Boolean adapt)	The strategy used for class discrimination.
void	setSubclassesLoaded(boolean loaded)	Whether this Discriminator has loaded subclasses yet.
void	setValue(Object value)	The discriminator value.
void	syncMappingInfo()	Update MappingInfo with our current mapping information.
String	toString()
void	update(OpenJPAStateManager sm, JDBCStore store, RowManager rm)	Set values for the mapping into the proper rows.

Methods inherited from class java.lang.Object

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

Field Details

NULL

public static final Object NULL

Null discriminator value marker.

Constructor Details

Discriminator

public Discriminator(ClassMapping mapping)

Constructor. Supply owning mapping.

Method Details

getRepository

public MetaDataRepository getRepository()

Description copied from interface: MetaDataContext

Access metadata repository.

Specified by:

getRepository in interface MetaDataContext

getMappingRepository

public MappingRepository getMappingRepository()

getClassMapping

public ClassMapping getClassMapping()

Return the owning mapping.

getStrategy

public DiscriminatorStrategy getStrategy()

The strategy used for class discrimination.

setStrategy

public void setStrategy(DiscriminatorStrategy strategy,
 Boolean adapt)

The strategy used for class discrimination. The adapt parameter determines whether to adapt when mapping the strategy; use null if the strategy should not be mapped.

getValue

public Object getValue()

The discriminator value.

setValue

public void setValue(Object value)

The discriminator value.

getMappingInfo

public DiscriminatorMappingInfo getMappingInfo()

Raw mapping data.

getColumns

public Column[] getColumns()

Columns used by this Discriminator.

setColumns

public void setColumns(Column[] cols)

Columns used by this Discriminator.

getColumnIO

public ColumnIO getColumnIO()

I/O information on the discriminator columns.

setColumnIO

public void setColumnIO(ColumnIO io)

I/O information on the discriminator columns.

getIndex

public Index getIndex()

Index on the Discriminator columns, or null if none.

setIndex

public void setIndex(Index idx)

Index on the Discriminator columns, or null if none.

refSchemaComponents

public void refSchemaComponents()

Increment the reference count of used schema components.

clearMapping

public void clearMapping()

Clear mapping information, including strategy.

syncMappingInfo

public void syncMappingInfo()

Update MappingInfo with our current mapping information.

getResolve

public int getResolve()

Resolve mode.

setResolve

public void setResolve(int mode)

Resolve mode.

setResolve

public void setResolve(int mode,
 boolean on)

Resolve mode.

resolve

public boolean resolve(int mode)

Resolve mapping information.

getSubclassesLoaded

public boolean getSubclassesLoaded()

Whether this Discriminator has loaded subclasses yet.

setSubclassesLoaded

public void setSubclassesLoaded(boolean loaded)

Whether this Discriminator has loaded subclasses yet.

addClassConditions

public boolean addClassConditions(Select sel,
 boolean subs,
 Joins joins)

Add WHERE conditions to the given select limiting the returned results to our mapping type, possibly including subclasses.

getAlias

public String getAlias()

Description copied from interface: Strategy

Return the alias of this strategy. For custom strategies, return the full class name.

Specified by:

getAlias in interface Strategy

map

public void map(boolean adapt)

Description copied from interface: Strategy

Map the owning mapping using this strategy.

Specified by:

map in interface Strategy

Parameters:

adapt - if true, use the owning mapping's raw mapping info to set its ORM data; if false, ORM data will already be set

initialize

public void initialize()

Description copied from interface: Strategy

Perform caching and other initialization operations. This method is called after Strategy.map(boolean), and after all related components have been mapped as well.

Specified by:

initialize in interface Strategy

insert

public void insert(OpenJPAStateManager sm,
 JDBCStore store,
 RowManager rm)
            throws SQLException

Description copied from interface: Strategy

Set values for the mapping into the proper rows. For class mappings, this method will be called only after the corresponding method has been called for all fields of this mapping.

Specified by:

insert in interface Strategy

Throws:

SQLException

update

public void update(OpenJPAStateManager sm,
 JDBCStore store,
 RowManager rm)
            throws SQLException

Description copied from interface: Strategy

Set values for the mapping into the proper rows.

Specified by:

update in interface Strategy

Throws:

SQLException

See Also:

• Strategy.insert(org.apache.openjpa.kernel.OpenJPAStateManager, org.apache.openjpa.jdbc.kernel.JDBCStore, org.apache.openjpa.jdbc.sql.RowManager)

delete

public void delete(OpenJPAStateManager sm,
 JDBCStore store,
 RowManager rm)
            throws SQLException

Description copied from interface: Strategy

Set the where values appropriately to delete the proper instance, and set all relations on non-secondary tables as updates. This allows foreign key analysis.

Specified by:

delete in interface Strategy

Throws:

SQLException

See Also:

• Strategy.insert(org.apache.openjpa.kernel.OpenJPAStateManager, org.apache.openjpa.jdbc.kernel.JDBCStore, org.apache.openjpa.jdbc.sql.RowManager)

isCustomInsert

public Boolean isCustomInsert(OpenJPAStateManager sm,
 JDBCStore store)

Description copied from interface: Strategy

Return Boolean.FALSE if this mapping does not customize the insert process, Boolean.TRUE if it does, or null if it does customize the insert, but also relies on the standard insert method being called. Implement the Strategy.customInsert(org.apache.openjpa.kernel.OpenJPAStateManager, org.apache.openjpa.jdbc.kernel.JDBCStore) method to implement the custom insertion behavior.

Specified by:

isCustomInsert in interface Strategy

isCustomUpdate

public Boolean isCustomUpdate(OpenJPAStateManager sm,
 JDBCStore store)

Description copied from interface: Strategy

Return Boolean.FALSE if this mapping does not customize the update process, Boolean.TRUE if it does, or null if it does customize the update, but also relies on the standard update method being called. Implement the Strategy.customUpdate(org.apache.openjpa.kernel.OpenJPAStateManager, org.apache.openjpa.jdbc.kernel.JDBCStore) method to override the default update behavior.

Specified by:

isCustomUpdate in interface Strategy

isCustomDelete

public Boolean isCustomDelete(OpenJPAStateManager sm,
 JDBCStore store)

Description copied from interface: Strategy

Return Boolean.FALSE if this mapping does not customize the delete process, Boolean.TRUE if it does, or null if it does customize the delete, but also relies on the standard delete method being called. Implement the Strategy.customDelete(org.apache.openjpa.kernel.OpenJPAStateManager, org.apache.openjpa.jdbc.kernel.JDBCStore) method to override the default deletion behavior.

Specified by:

isCustomDelete in interface Strategy

customInsert

public void customInsert(OpenJPAStateManager sm,
 JDBCStore store)
                  throws SQLException

Description copied from interface: Strategy

Override this method to customize flushing this mapping. For classes, this method must also flush all fields. For fields, this method is called after the owning object is inserted, so if this field is in a row with other fields, that row will already exist.

Specified by:

customInsert in interface Strategy

Throws:

SQLException

customUpdate

public void customUpdate(OpenJPAStateManager sm,
 JDBCStore store)
                  throws SQLException

Description copied from interface: Strategy

Override this method to customize flushing this mapping. For classes, this method must also flush all fields.

Specified by:

customUpdate in interface Strategy

Throws:

SQLException

customDelete

public void customDelete(OpenJPAStateManager sm,
 JDBCStore store)
                  throws SQLException

Description copied from interface: Strategy

Override this method to customize flushing this mapping. For classes, this method must also flush all fields. For fields, this method will be called after the owning object is deleted.

Specified by:

customDelete in interface Strategy

Throws:

SQLException

setDiscriminator

public void setDiscriminator(Discriminator owner)

Description copied from interface: DiscriminatorStrategy

Set the Discriminator that uses this strategy. This will be called before use.

Specified by:

setDiscriminator in interface DiscriminatorStrategy

select

public boolean select(Select sel,
 ClassMapping mapping)

Description copied from interface: DiscriminatorStrategy

Select the data for this Discriminator.

Specified by:

select in interface DiscriminatorStrategy

mapping - the known base class being selected; this may not be the base class in the inheritance hierarchy

Returns:

true if anything was selected; false otherwise

loadSubclasses

public void loadSubclasses(JDBCStore store)
                    throws SQLException,
ClassNotFoundException

Description copied from interface: DiscriminatorStrategy

Load all subclasses of the owning class mapping into the JVM.

Specified by:

loadSubclasses in interface DiscriminatorStrategy

Throws:

SQLException

ClassNotFoundException

getClass

public Class<?> getClass(JDBCStore store,
 ClassMapping base,
 Result result)
                  throws SQLException,
ClassNotFoundException

Description copied from interface: DiscriminatorStrategy

Return the class for the current result row.

Specified by:

getClass in interface DiscriminatorStrategy

Throws:

SQLException

ClassNotFoundException

hasClassConditions

public boolean hasClassConditions(ClassMapping base,
 boolean subs)

Description copied from interface: DiscriminatorStrategy

Whether any class conditions are necessary.

Specified by:

hasClassConditions in interface DiscriminatorStrategy

See Also:

• DiscriminatorStrategy.getClassConditions(org.apache.openjpa.jdbc.sql.Select, org.apache.openjpa.jdbc.sql.Joins, org.apache.openjpa.jdbc.meta.ClassMapping, boolean)

getClassConditions

public SQLBuffer getClassConditions(Select sel,
 Joins joins,
 ClassMapping base,
 boolean subs)

Description copied from interface: DiscriminatorStrategy

Return SQL to limit the classes selected as much as possible to the given base class, and optionally its subclasses. The select and joins instances are supplied in order to get column aliases.

Specified by:

getClassConditions in interface DiscriminatorStrategy

toString

public String toString()

Overrides:

toString in class Object

setJavaType

public void setJavaType(int javaType)

getJavaType

public int getJavaType()