org.apache.openjpa.jdbc.meta
Class Discriminator

java.lang.Object
  extended by 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
static Object NULL
          Null discriminator value marker.
 
Fields inherited from interface org.apache.openjpa.meta.MetaDataModes
MODE_MAPPING, MODE_MAPPING_INIT, MODE_META, MODE_NONE, MODE_QUERY
 
Constructor Summary
Discriminator(ClassMapping mapping)
          Constructor.
 
Method Summary
 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.
 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 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 Detail

NULL

public static final Object NULL
Null discriminator value marker.

Constructor Detail

Discriminator

public Discriminator(ClassMapping mapping)
Constructor. Supply owning mapping.

Method Detail

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


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