org.apache.openjpa.jdbc.meta.strats
Class StoreCollectionFieldStrategy

java.lang.Object
  org.apache.openjpa.jdbc.meta.strats.AbstractStrategy
      org.apache.openjpa.jdbc.meta.strats.AbstractFieldStrategy
          org.apache.openjpa.jdbc.meta.strats.ContainerFieldStrategy
              org.apache.openjpa.jdbc.meta.strats.StoreCollectionFieldStrategy

All Implemented Interfaces:

Serializable, FieldStrategy, Strategy

Direct Known Subclasses:

HandlerCollectionTableFieldStrategy, RelationToManyInverseKeyFieldStrategy, RelationToManyTableFieldStrategy

public abstract class StoreCollectionFieldStrategy
extends ContainerFieldStrategy

Base class for strategies that are stored as a collection, even if their field value is something else. Handles data loading and basic query functionality. Subclasses must implement abstract methods and insert/update/delete behavior as well as overriding FieldStrategy.toDataStoreValue(java.lang.Object, org.apache.openjpa.jdbc.kernel.JDBCStore), FieldStrategy.join(org.apache.openjpa.jdbc.sql.Joins, boolean), and FieldStrategy.joinRelation(org.apache.openjpa.jdbc.sql.Joins, boolean, boolean) if necessary.

Author:

Abe White

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.openjpa.jdbc.meta.strats.AbstractFieldStrategy

field

Constructor Summary

StoreCollectionFieldStrategy()

Method Summary

protected void	add(JDBCStore store, Object coll, Object obj) Add an item to the data structure representing a field value.
protected ForeignKey	getJoinForeignKey()
protected abstract ForeignKey	getJoinForeignKey(ClassMapping elem) Return the foreign key used to join to the owning field for the given element mapping from ContainerFieldStrategy.getIndependentElementMappings(boolean) (or null).
boolean	isEagerSelectToMany() Whether the eager joins or selects used by this field are to-many.
protected abstract Joins	join(Joins joins, ClassMapping elem) Join to the owning field table for the given element mapping from ContainerFieldStrategy.getIndependentElementMappings(boolean) (or null).
protected abstract Joins	joinElementRelation(Joins joins, ClassMapping elem) Join this value's table to the table for the given element mapping from ContainerFieldStrategy.getIndependentElementMappings(boolean) (or null).
void	load(OpenJPAStateManager sm, JDBCStore store, JDBCFetchConfiguration fetch) Load secondary data using a connection from the store manager.
void	loadEagerJoin(OpenJPAStateManager sm, JDBCStore store, JDBCFetchConfiguration fetch, Result res) Load the joined eager result.
Object	loadEagerParallel(OpenJPAStateManager sm, JDBCStore store, JDBCFetchConfiguration fetch, Object res) Load the batched eager result.
protected abstract Object	loadElement(OpenJPAStateManager sm, JDBCStore store, JDBCFetchConfiguration fetch, Result res, Joins joins) Load an element of the collection.
Object	loadProjection(JDBCStore store, JDBCFetchConfiguration fetch, Result res, Joins joins) Load this field value using the given result.
protected abstract Proxy	newLRSProxy() Return a large result set proxy for this field.
protected Union	newUnion(OpenJPAStateManager sm, JDBCStore store, JDBCFetchConfiguration fetch, ClassMapping[] elems, Joins[] resJoins)
protected Joins	selectAll(Select sel, ClassMapping elem, OpenJPAStateManager sm, JDBCStore store, JDBCFetchConfiguration fetch, int eagerMode) Select data for loading, starting in field table.
void	selectEagerJoin(Select sel, OpenJPAStateManager sm, JDBCStore store, JDBCFetchConfiguration fetch, int eagerMode) Fill in joined select to related objects.
void	selectEagerParallel(SelectExecutor sel, OpenJPAStateManager sm, JDBCStore store, JDBCFetchConfiguration fetch, int eagerMode) Fill in parallel eager select for related objects.
protected abstract void	selectElement(Select sel, ClassMapping elem, JDBCStore store, JDBCFetchConfiguration fetch, int eagerMode, Joins joins) Implement this method to select the elements of this field for the given element mapping from ContainerFieldStrategy.getIndependentElementMappings(boolean) (or null).
int	supportsSelect(Select sel, int type, OpenJPAStateManager sm, JDBCStore store, JDBCFetchConfiguration fetch) Return whether this mapping can perform the given select type.
protected Collection	toCollection(Object val) Convert the field value to a collection.

Methods inherited from class org.apache.openjpa.jdbc.meta.strats.ContainerFieldStrategy

appendIsEmpty, appendIsNotEmpty, appendIsNotNull, appendIsNull, appendJoinCount, appendSize, appendUnaliasedJoin, getIndependentElementMappings

Methods inherited from class org.apache.openjpa.jdbc.meta.strats.AbstractFieldStrategy

assertNotMappedBy, isVersionable, join, joinKey, joinKeyRelation, joinRelation, load, loadKeyProjection, select, setFieldMapping, toDataStoreValue, toKeyDataStoreValue, where

Methods inherited from class org.apache.openjpa.jdbc.meta.strats.AbstractStrategy

customDelete, customInsert, customUpdate, delete, getAlias, initialize, insert, isCustomDelete, isCustomInsert, isCustomUpdate, map, update

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.openjpa.jdbc.meta.Strategy

customDelete, customInsert, customUpdate, delete, getAlias, initialize, insert, isCustomDelete, isCustomInsert, isCustomUpdate, map, update

Constructor Detail

StoreCollectionFieldStrategy

public StoreCollectionFieldStrategy()

Method Detail

getJoinForeignKey

protected abstract ForeignKey getJoinForeignKey(ClassMapping elem)

Return the foreign key used to join to the owning field for the given element mapping from ContainerFieldStrategy.getIndependentElementMappings(boolean) (or null).

selectElement

protected abstract void selectElement(Select sel,
                                      ClassMapping elem,
                                      JDBCStore store,
                                      JDBCFetchConfiguration fetch,
                                      int eagerMode,
                                      Joins joins)

Implement this method to select the elements of this field for the given element mapping from ContainerFieldStrategy.getIndependentElementMappings(boolean) (or null). Elements of the result will be loaded with loadElement(org.apache.openjpa.kernel.OpenJPAStateManager, org.apache.openjpa.jdbc.kernel.JDBCStore, org.apache.openjpa.jdbc.kernel.JDBCFetchConfiguration, org.apache.openjpa.jdbc.sql.Result, org.apache.openjpa.jdbc.sql.Joins).

loadElement

protected abstract Object loadElement(OpenJPAStateManager sm,
                                      JDBCStore store,
                                      JDBCFetchConfiguration fetch,
                                      Result res,
                                      Joins joins)
                               throws SQLException

Load an element of the collection. The given state manager might be null if the load is for a projection or for processing eager parallel results.

Throws:

SQLException

joinElementRelation

protected abstract Joins joinElementRelation(Joins joins,
                                             ClassMapping elem)

Join this value's table to the table for the given element mapping from ContainerFieldStrategy.getIndependentElementMappings(boolean) (or null).

See Also:

FieldMapping.joinRelation(org.apache.openjpa.jdbc.sql.Joins, boolean, boolean)

join

protected abstract Joins join(Joins joins,
                              ClassMapping elem)

Join to the owning field table for the given element mapping from ContainerFieldStrategy.getIndependentElementMappings(boolean) (or null).

newLRSProxy

protected abstract Proxy newLRSProxy()

Return a large result set proxy for this field.

toCollection

protected Collection toCollection(Object val)

Convert the field value to a collection. Handles collections and arrays by default.

add

protected void add(JDBCStore store,
                   Object coll,
                   Object obj)

Add an item to the data structure representing a field value. By default, assumes the structure is a collection.

supportsSelect

public int supportsSelect(Select sel,
                          int type,
                          OpenJPAStateManager sm,
                          JDBCStore store,
                          JDBCFetchConfiguration fetch)

Description copied from interface: FieldStrategy

Return whether this mapping can perform the given select type. Return 0 if the given type is not supported. If the given type is an eager parallel type, return the number of UNIONed selects necessary to fetch the data. Otherwise, return any positive number if the type is supported. The given state manager may be null if selecting multiple instances.

Specified by:

supportsSelect in interface FieldStrategy

Overrides:

supportsSelect in class AbstractFieldStrategy

See Also:

Select

selectEagerParallel

public void selectEagerParallel(SelectExecutor sel,
                                OpenJPAStateManager sm,
                                JDBCStore store,
                                JDBCFetchConfiguration fetch,
                                int eagerMode)

Description copied from interface: FieldStrategy

Fill in parallel eager select for related objects.

Specified by:

selectEagerParallel in interface FieldStrategy

Overrides:

selectEagerParallel in class AbstractFieldStrategy

See Also:

FieldStrategy.select(org.apache.openjpa.jdbc.sql.Select, org.apache.openjpa.kernel.OpenJPAStateManager, org.apache.openjpa.jdbc.kernel.JDBCStore, org.apache.openjpa.jdbc.kernel.JDBCFetchConfiguration, int)

selectEagerJoin

public void selectEagerJoin(Select sel,
                            OpenJPAStateManager sm,
                            JDBCStore store,
                            JDBCFetchConfiguration fetch,
                            int eagerMode)

Description copied from interface: FieldStrategy

Fill in joined select to related objects.

Specified by:

selectEagerJoin in interface FieldStrategy

Overrides:

selectEagerJoin in class AbstractFieldStrategy

See Also:

FieldStrategy.select(org.apache.openjpa.jdbc.sql.Select, org.apache.openjpa.kernel.OpenJPAStateManager, org.apache.openjpa.jdbc.kernel.JDBCStore, org.apache.openjpa.jdbc.kernel.JDBCFetchConfiguration, int)

isEagerSelectToMany

public boolean isEagerSelectToMany()

Description copied from interface: FieldStrategy

Whether the eager joins or selects used by this field are to-many.

Specified by:

isEagerSelectToMany in interface FieldStrategy

Overrides:

isEagerSelectToMany in class AbstractFieldStrategy

loadEagerParallel

public Object loadEagerParallel(OpenJPAStateManager sm,
                                JDBCStore store,
                                JDBCFetchConfiguration fetch,
                                Object res)
                         throws SQLException

Description copied from interface: FieldStrategy

Load the batched eager result.

Specified by:

loadEagerParallel in interface FieldStrategy

Overrides:

loadEagerParallel in class AbstractFieldStrategy

res - originally the Result to load from, but this method may return a processed result form that will be passed to subsequent calls

Throws:

SQLException

loadEagerJoin

public void loadEagerJoin(OpenJPAStateManager sm,
                          JDBCStore store,
                          JDBCFetchConfiguration fetch,
                          Result res)
                   throws SQLException

Description copied from interface: FieldStrategy

Load the joined eager result.

Specified by:

loadEagerJoin in interface FieldStrategy

Overrides:

loadEagerJoin in class AbstractFieldStrategy

Throws:

SQLException

load

public void load(OpenJPAStateManager sm,
                 JDBCStore store,
                 JDBCFetchConfiguration fetch)
          throws SQLException

Description copied from interface: FieldStrategy

Load secondary data using a connection from the store manager.

Specified by:

load in interface FieldStrategy

Overrides:

load in class AbstractFieldStrategy

Throws:

SQLException

newUnion

protected Union newUnion(OpenJPAStateManager sm,
                         JDBCStore store,
                         JDBCFetchConfiguration fetch,
                         ClassMapping[] elems,
                         Joins[] resJoins)

selectAll

protected Joins selectAll(Select sel,
                          ClassMapping elem,
                          OpenJPAStateManager sm,
                          JDBCStore store,
                          JDBCFetchConfiguration fetch,
                          int eagerMode)

Select data for loading, starting in field table.

loadProjection

public Object loadProjection(JDBCStore store,
                             JDBCFetchConfiguration fetch,
                             Result res,
                             Joins joins)
                      throws SQLException

Description copied from interface: FieldStrategy

Load this field value using the given result. The result will contain the columns from ValueMapping.getColumns().

Specified by:

loadProjection in interface FieldStrategy

Overrides:

loadProjection in class AbstractFieldStrategy

Throws:

SQLException

getJoinForeignKey

protected ForeignKey getJoinForeignKey()

Specified by:

getJoinForeignKey in class ContainerFieldStrategy