Package org.apache.cayenne

Class BaseContext

java.lang.Object

org.apache.cayenne.BaseContext

All Implemented Interfaces:

Serializable, DataChannel, ObjectContext

Direct Known Subclasses:

DataContext

public abstract class BaseContext
extends Object
implements ObjectContext

A common base superclass for Cayenne ObjectContext implementors.

Since:

3.0

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
protected DataChannel	channel
protected EntityResolver	entityResolver
protected ObjectContextGraphAction	graphAction	Graph action that handles property changes
protected QueryCache	queryCache
protected static ThreadLocal<ObjectContext>	threadObjectContext	A holder of a ObjectContext bound to the current thread.
protected Map<String,Object>	userProperties	Stores user defined properties associated with this DataContext.
protected boolean	validatingObjectsOnCommit

Fields inherited from interface org.apache.cayenne.DataChannel

FLUSH_CASCADE_SYNC, FLUSH_NOCASCADE_SYNC, GRAPH_CHANGED_SUBJECT, GRAPH_FLUSHED_SUBJECT, GRAPH_ROLLEDBACK_SUBJECT, ROLLBACK_CASCADE_SYNC

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	BaseContext()

Method Summary

Modifier and Type	Method	Description
protected void	attachToChannel(DataChannel channel)	Attaches to a provided DataChannel.
protected void	attachToRuntime(Injector injector)	Attaches this context to the CayenneRuntime whose Injector is passed as an argument to this method.
protected boolean	attachToRuntimeIfNeeded()	Checks whether this context is attached to Cayenne runtime stack and if not, attempts to attach itself to the runtime using Injector returned from the call to CayenneRuntime.getThreadInjector().
<T> ResultBatchIterator<T>	batchIterator(Select<T> query, int size)	Creates a ResultBatchIterator based on the provided query and batch size.
static void	bindThreadObjectContext(ObjectContext context)	Binds a ObjectContext to the current thread.
abstract void	commitChanges()	Flushes all changes to objects in this context to the parent DataChannel, cascading flush operation all the way through the stack, ultimately saving data in the database.
abstract void	commitChangesToParent()	Flushes all changes to objects in this context to the parent DataChannel.
abstract Collection<?>	deletedObjects()	Returns a collection of objects that are registered with this ObjectContext and have a state PersistenceState.DELETED
void	deleteObject(Object object)	Schedules deletion of a persistent object.
void	deleteObjects(Collection<?> objects)	Schedules deletion of a collection of persistent objects.
<T> void	deleteObjects(T... objects)	Schedules deletion of one or more persistent objects.
protected void	fireDataChannelChanged(Object postedBy, GraphDiff changes)
protected void	fireDataChannelCommitted(Object postedBy, GraphDiff changes)
protected void	fireDataChannelRolledback(Object postedBy, GraphDiff changes)
DataChannel	getChannel()	Returns an DataChannel used by this context.
EntityResolver	getEntityResolver()	Returns EntityResolver that stores all mapping information accessible by this ObjectContext.
EventManager	getEventManager()	Returns EventManager associated with the ObjectStore.
abstract GraphManager	getGraphManager()	Returns GraphManager that manages object graph associated with this context.
QueryCache	getQueryCache()
static ObjectContext	getThreadObjectContext()	Returns the ObjectContext bound to the current thread.
protected Map<String,Object>	getUserProperties()	Returns a map of user-defined properties associated with this DataContext.
Object	getUserProperty(String key)	Returns a user-defined property previously set via 'setUserProperty'.
protected void	injectInitialValue(Object obj)	If ObjEntity qualifier is set, asks it to inject initial value to an object.
void	invalidateObjects(Collection<?> objects)	Invalidates a Collection of persistent objects.
<T> void	invalidateObjects(T... objects)	Invalidates one or more persistent objects.
boolean	isValidatingObjectsOnCommit()	Returns whether this ObjectContext performs object validation before commit is executed.
<T> void	iterate(Select<T> query, ResultIteratorCallback<T> callback)	Creates a ResultIterator based on the provided query and passes it to a callback for processing.
abstract <T> ResultIterator<T>	iterator(Select<T> query)	Creates a ResultIterator based on the provided query.
<T extends Persistent> T	localObject(T objectFromAnotherContext)	Returns a local copy of 'objectFromAnotherContext' object.
abstract Collection<?>	modifiedObjects()	Returns a collection of objects that are registered with this ObjectContext and have a state PersistenceState.MODIFIED
abstract <T> T	newObject(Class<T> persistentClass)	Creates a new persistent object of a given class scheduled to be inserted to the database on next commit.
abstract Collection<?>	newObjects()	Returns a collection of objects that are registered with this ObjectContext and have a state PersistenceState.NEW
protected abstract GraphDiff	onContextFlush(ObjectContext originatingContext, GraphDiff changes, boolean cascade)
GraphDiff	onSync(ObjectContext originatingContext, GraphDiff changes, int syncType)	Processes synchronization request from a child ObjectContext, returning a GraphDiff that describes changes to objects made on the receiving end as a result of synchronization.
abstract QueryResponse	performGenericQuery(Query query)	Executes any kind of query providing the result in a form of QueryResponse.
abstract List	performQuery(Query query)	Executes a selecting query, returning a list of persistent objects or data rows.
void	prepareForAccess(Persistent object, String property, boolean lazyFaulting)	A callback method that child Persistent objects are expected to call before accessing property values.
void	propertyChanged(Persistent object, String property, Object oldValue, Object newValue)	A callback method that child Persistent objects are expected to call from inside the setter after modifying a value of a persistent property, including "simple" and "arc" properties.
abstract void	registerNewObject(Object object)	Registers a transient object with the context.
abstract void	rollbackChanges()	Resets all uncommitted changes made to the objects in this ObjectContext, cascading rollback operation all the way through the stack.
abstract void	rollbackChangesLocally()	Resets all uncommitted changes made to the objects in this ObjectContext.
<T> List<T>	select(Select<T> query)	Executes a selecting query, returning a list of persistent objects or data rows.
<T> T	selectFirst(Select<T> query)	Selects a single object using provided query.
<T> T	selectOne(Select<T> query)	Executes a selecting query, returning either NULL if query matched no objects, or a single object.
void	setChannel(DataChannel channel)	Sets a new DataChannel for this context.
void	setEntityResolver(EntityResolver entityResolver)
void	setQueryCache(QueryCache queryCache)	Sets a QueryCache to be used for storing cached query results.
void	setUserProperty(String key, Object value)	Sets a user-defined property.
void	setValidatingObjectsOnCommit(boolean flag)	Sets the property defining whether this ObjectContext should perform object validation before commit is executed.
abstract Collection<?>	uncommittedObjects()	Returns a collection of MODIFIED, DELETED or NEW objects.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.cayenne.DataChannel

onQuery

Methods inherited from interface org.apache.cayenne.ObjectContext

hasChanges

Field Detail

threadObjectContext

protected static final ThreadLocal<ObjectContext> threadObjectContext

A holder of a ObjectContext bound to the current thread.

Since:

3.0

channel

protected transient DataChannel channel

queryCache

protected transient QueryCache queryCache

entityResolver

protected transient EntityResolver entityResolver

validatingObjectsOnCommit

protected boolean validatingObjectsOnCommit

graphAction

protected ObjectContextGraphAction graphAction

Graph action that handles property changes

Since:

3.1

userProperties

protected volatile Map<String,Object> userProperties

Stores user defined properties associated with this DataContext.

Since:

3.0

Constructor Detail

BaseContext

protected BaseContext()

Method Detail

getThreadObjectContext

public static ObjectContext getThreadObjectContext()
                                            throws IllegalStateException

Returns the ObjectContext bound to the current thread.

Returns:

the ObjectContext associated with caller thread.

Throws:

IllegalStateException - if there is no ObjectContext bound to the current thread.

Since:

3.0

bindThreadObjectContext

public static void bindThreadObjectContext(ObjectContext context)

Binds a ObjectContext to the current thread. ObjectContext can later be retrieved by users in the same thread by calling getThreadObjectContext(). Using null parameter will unbind currently bound ObjectContext.

Since:

3.0

attachToRuntimeIfNeeded

protected boolean attachToRuntimeIfNeeded()

Checks whether this context is attached to Cayenne runtime stack and if not, attempts to attach itself to the runtime using Injector returned from the call to CayenneRuntime.getThreadInjector(). If thread Injector is not available and the context is not attached, throws CayenneRuntimeException.

This method is called internally by the context before access to transient variables to allow the context to attach to the stack lazily following deserialization.

Returns:

true if the context successfully attached to the thread runtime, false - if it was already attached.

Since:

3.1

attachToRuntime

protected void attachToRuntime(Injector injector)

Attaches this context to the CayenneRuntime whose Injector is passed as an argument to this method.

Since:

3.1

attachToChannel

protected void attachToChannel(DataChannel channel)

Attaches to a provided DataChannel.

Since:

3.1

commitChanges

public abstract void commitChanges()

Description copied from interface: ObjectContext

Flushes all changes to objects in this context to the parent DataChannel, cascading flush operation all the way through the stack, ultimately saving data in the database.

Specified by:

commitChanges in interface ObjectContext

commitChangesToParent

public abstract void commitChangesToParent()

Description copied from interface: ObjectContext

Flushes all changes to objects in this context to the parent DataChannel. Same as ObjectContext.commitChanges(), but no cascading flush occurs.

Specified by:

commitChangesToParent in interface ObjectContext

deleteObject

public void deleteObject(Object object)
                  throws DeleteDenyException

Description copied from interface: ObjectContext

Schedules deletion of a persistent object.

Specified by:

deleteObject in interface ObjectContext

Throws:

DeleteDenyException - if a DeleteRule.DENY delete rule is applicable for object deletion.

deletedObjects

public abstract Collection<?> deletedObjects()

Description copied from interface: ObjectContext

Returns a collection of objects that are registered with this ObjectContext and have a state PersistenceState.DELETED

Specified by:

deletedObjects in interface ObjectContext

getChannel

public DataChannel getChannel()

Description copied from interface: ObjectContext

Returns an DataChannel used by this context.

Specified by:

getChannel in interface ObjectContext

setChannel

public void setChannel(DataChannel channel)

Sets a new DataChannel for this context.

Since:

3.1

getEntityResolver

public EntityResolver getEntityResolver()

Description copied from interface: ObjectContext

Returns EntityResolver that stores all mapping information accessible by this ObjectContext.

Specified by:

getEntityResolver in interface DataChannel

Specified by:

getEntityResolver in interface ObjectContext

setEntityResolver

public void setEntityResolver(EntityResolver entityResolver)

Since:

3.1

isValidatingObjectsOnCommit

public boolean isValidatingObjectsOnCommit()

Returns whether this ObjectContext performs object validation before commit is executed.

Since:

1.1

setValidatingObjectsOnCommit

public void setValidatingObjectsOnCommit(boolean flag)

Sets the property defining whether this ObjectContext should perform object validation before commit is executed.

Since:

1.1

localObject

public <T extends Persistent> T localObject(T objectFromAnotherContext)

Description copied from interface: ObjectContext

Returns a local copy of 'objectFromAnotherContext' object. "Local" means that the returned object is registered in this context. If the local object hasn't been previously cached in this context, a hollow object is created and returned to the caller. No DB query is performed to resolve an object.

Note that passing an object with a non-existing id, may later result in FaultFailureException on attempt to read returned object properties.

Specified by:

localObject in interface ObjectContext

Since:

3.1

getGraphManager

public abstract GraphManager getGraphManager()

Description copied from interface: ObjectContext

Returns GraphManager that manages object graph associated with this context.

Specified by:

getGraphManager in interface ObjectContext

modifiedObjects

public abstract Collection<?> modifiedObjects()

Description copied from interface: ObjectContext

Returns a collection of objects that are registered with this ObjectContext and have a state PersistenceState.MODIFIED

Specified by:

modifiedObjects in interface ObjectContext

newObject

public abstract <T> T newObject(Class<T> persistentClass)

Description copied from interface: ObjectContext

Creates a new persistent object of a given class scheduled to be inserted to the database on next commit.

Specified by:

newObject in interface ObjectContext

registerNewObject

public abstract void registerNewObject(Object object)

Description copied from interface: ObjectContext

Registers a transient object with the context. The difference with ObjectContext.newObject(Class) is that a user creates an object herself, before attaching it to the context, instead of relying on Cayenne to do that.

Specified by:

registerNewObject in interface ObjectContext

Parameters:

object - new object that needs to be made persistent.

newObjects

public abstract Collection<?> newObjects()

Description copied from interface: ObjectContext

Returns a collection of objects that are registered with this ObjectContext and have a state PersistenceState.NEW

Specified by:

newObjects in interface ObjectContext

performGenericQuery

public abstract QueryResponse performGenericQuery(Query query)

Description copied from interface: ObjectContext

Executes any kind of query providing the result in a form of QueryResponse.

Specified by:

performGenericQuery in interface ObjectContext

performQuery

public abstract List performQuery(Query query)

Description copied from interface: ObjectContext

Executes a selecting query, returning a list of persistent objects or data rows.

Specified by:

performQuery in interface ObjectContext

select

public <T> List<T> select(Select<T> query)

Description copied from interface: ObjectContext

Executes a selecting query, returning a list of persistent objects or data rows.

Specified by:

select in interface ObjectContext

Since:

4.0

selectOne

public <T> T selectOne(Select<T> query)

Description copied from interface: ObjectContext

Executes a selecting query, returning either NULL if query matched no objects, or a single object. If query matches more than one object, CayenneRuntimeException is thrown.

Specified by:

selectOne in interface ObjectContext

Since:

4.0

selectFirst

public <T> T selectFirst(Select<T> query)

Description copied from interface: ObjectContext

Selects a single object using provided query. The query itself can match any number of objects, but will return only the first one. It returns null if no objects were matched.

If it matched more than one object, the first object from the list is returned. This makes 'selectFirst' different from ObjectContext.selectOne(Select), which would throw in this situation. 'selectFirst' is useful e.g. when the query is ordered and we only want to see the first object (e.g. "most recent news article"), etc.

Selecting the first object via "Select.selectFirst(ObjectContext)" is more comprehensible than selecting via "ObjectContext.selectFirst(Select)", because implementations of "Select" set fetch size limit to one.

Specified by:

selectFirst in interface ObjectContext

Since:

4.0

iterate

public <T> void iterate(Select<T> query,
                        ResultIteratorCallback<T> callback)

Description copied from interface: ObjectContext

Creates a ResultIterator based on the provided query and passes it to a callback for processing. The caller does not need to worry about closing the iterator. This method takes care of it.

Specified by:

iterate in interface ObjectContext

Since:

4.0

iterator

public abstract <T> ResultIterator<T> iterator(Select<T> query)

Description copied from interface: ObjectContext

Creates a ResultIterator based on the provided query. It is usually backed by an open result set and is useful for processing of large data sets, preserving a constant memory footprint. The caller must wrap iteration in try/finally (or try-with-resources for Java 1.7 and higher) and close the ResultIterator explicitly. Or use ObjectContext.iterate(Select, ResultIteratorCallback) as an alternative.

Specified by:

iterator in interface ObjectContext

batchIterator

public <T> ResultBatchIterator<T> batchIterator(Select<T> query,
                                                int size)

Description copied from interface: ObjectContext

Creates a ResultBatchIterator based on the provided query and batch size. It is usually backed by an open result set and is useful for processing of large data sets, preserving a constant memory footprint. The caller must wrap iteration in try/finally (or try-with-resources for Java 1.7 and higher) and close the ResultBatchIterator explicitly.

Specified by:

batchIterator in interface ObjectContext

prepareForAccess

public void prepareForAccess(Persistent object,
                             String property,
                             boolean lazyFaulting)

Description copied from interface: ObjectContext

A callback method that child Persistent objects are expected to call before accessing property values. This callback allows ObjectContext to "inflate" unresolved objects on demand and also resolve properties that rely on lazy faulting.

Specified by:

prepareForAccess in interface ObjectContext

propertyChanged

public void propertyChanged(Persistent object,
                            String property,
                            Object oldValue,
                            Object newValue)

Description copied from interface: ObjectContext

A callback method that child Persistent objects are expected to call from inside the setter after modifying a value of a persistent property, including "simple" and "arc" properties.

Specified by:

propertyChanged in interface ObjectContext

rollbackChanges

public abstract void rollbackChanges()

Description copied from interface: ObjectContext

Resets all uncommitted changes made to the objects in this ObjectContext, cascading rollback operation all the way through the stack.

Specified by:

rollbackChanges in interface ObjectContext

rollbackChangesLocally

public abstract void rollbackChangesLocally()

Description copied from interface: ObjectContext

Resets all uncommitted changes made to the objects in this ObjectContext. Same as ObjectContext.rollbackChanges(), but rollback is local to this context and no cascading changes undoing occurs.

Specified by:

rollbackChangesLocally in interface ObjectContext

uncommittedObjects

public abstract Collection<?> uncommittedObjects()

Description copied from interface: ObjectContext

Returns a collection of MODIFIED, DELETED or NEW objects.

Specified by:

uncommittedObjects in interface ObjectContext

getQueryCache

public QueryCache getQueryCache()

setQueryCache

public void setQueryCache(QueryCache queryCache)

Sets a QueryCache to be used for storing cached query results.

getEventManager

public EventManager getEventManager()

Returns EventManager associated with the ObjectStore.

Specified by:

getEventManager in interface DataChannel

Since:

1.2

onSync

public GraphDiff onSync(ObjectContext originatingContext,
                        GraphDiff changes,
                        int syncType)

Description copied from interface: DataChannel

Processes synchronization request from a child ObjectContext, returning a GraphDiff that describes changes to objects made on the receiving end as a result of synchronization.

Specified by:

onSync in interface DataChannel

Parameters:

originatingContext - an ObjectContext that initiated the sync. Can be null.

changes - diff from the context that initiated the sync.

syncType - One of DataChannel.FLUSH_NOCASCADE_SYNC, DataChannel.FLUSH_CASCADE_SYNC, DataChannel.ROLLBACK_CASCADE_SYNC.

onContextFlush

protected abstract GraphDiff onContextFlush(ObjectContext originatingContext,
                                            GraphDiff changes,
                                            boolean cascade)

fireDataChannelCommitted

protected void fireDataChannelCommitted(Object postedBy,
                                        GraphDiff changes)

Since:

1.2

fireDataChannelRolledback

protected void fireDataChannelRolledback(Object postedBy,
                                         GraphDiff changes)

Since:

1.2

fireDataChannelChanged

protected void fireDataChannelChanged(Object postedBy,
                                      GraphDiff changes)

Since:

1.2

invalidateObjects

public void invalidateObjects(Collection<?> objects)

Description copied from interface: ObjectContext

Invalidates a Collection of persistent objects. This operation only applies to the objects already committed to the database and does nothing to the NEW objects. It would remove each object's snapshot from caches and change object's state to HOLLOW. On the next access to this object, the object will be refetched.

Specified by:

invalidateObjects in interface ObjectContext

invalidateObjects

public <T> void invalidateObjects(T... objects)

Description copied from interface: ObjectContext

Invalidates one or more persistent objects. Same as ObjectContext.invalidateObjects(Collection) only with a vararg argument list for easier invalidation of individual objects. If no arguments are passed to this method, it does nothing.

Specified by:

invalidateObjects in interface ObjectContext

Since:

3.1

getUserProperties

protected Map<String,Object> getUserProperties()

Returns a map of user-defined properties associated with this DataContext.

Since:

3.0

getUserProperty

public Object getUserProperty(String key)

Returns a user-defined property previously set via 'setUserProperty'. Note that it is a caller responsibility to synchronize access to properties.

Specified by:

getUserProperty in interface ObjectContext

Since:

3.0

setUserProperty

public void setUserProperty(String key,
                            Object value)

Sets a user-defined property. Note that it is a caller responsibility to synchronize access to properties.

Specified by:

setUserProperty in interface ObjectContext

Since:

3.0

injectInitialValue

protected void injectInitialValue(Object obj)

If ObjEntity qualifier is set, asks it to inject initial value to an object. Also performs all Persistent initialization operations

deleteObjects

public <T> void deleteObjects(T... objects)
                       throws DeleteDenyException

Description copied from interface: ObjectContext

Schedules deletion of one or more persistent objects. Same as ObjectContext.deleteObjects(Collection) only with a vararg argument list for easier deletion of individual objects.

Specified by:

deleteObjects in interface ObjectContext

Throws:

DeleteDenyException - if a DeleteRule.DENY delete rule is applicable for object deletion.

Since:

3.1

deleteObjects

public void deleteObjects(Collection<?> objects)
                   throws DeleteDenyException

Description copied from interface: ObjectContext

Schedules deletion of a collection of persistent objects.

Specified by:

deleteObjects in interface ObjectContext

Throws:

DeleteDenyException - if a DeleteRule.DENY delete rule is applicable for object deletion.