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

java.lang.Object
  extended by org.apache.openjpa.jdbc.meta.strats.AbstractStrategy
      extended by org.apache.openjpa.jdbc.meta.strats.AbstractFieldStrategy
          extended by org.apache.openjpa.jdbc.meta.strats.ContainerFieldStrategy
              extended by 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.
(package private)  boolean requiresOrderBy()
           
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
appendIndex, appendIsEmpty, appendIsNotEmpty, appendIsNotNull, appendIsNull, appendJoinCount, appendSize, appendUnaliasedJoin, getIndependentElementMappings
 
Methods inherited from class org.apache.openjpa.jdbc.meta.strats.AbstractFieldStrategy
appendType, 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

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

requiresOrderBy

boolean requiresOrderBy()


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