org.apache.cayenne
Class CayenneContext

java.lang.Object
  org.apache.cayenne.BaseContext
      org.apache.cayenne.CayenneContext

All Implemented Interfaces:

Serializable, DataChannel, ObjectContext

public class CayenneContext
extends BaseContext

A default generic implementation of ObjectContext suitable for accessing Cayenne from either an ORM or a client tiers. Communicates with Cayenne via a DataChannel.

Since:

1.2

See Also:

Serialized Form

Field Summary

protected EntityResolver

entityResolver

Fields inherited from class org.apache.cayenne.BaseContext

channel, queryCache, threadObjectContext, userProperties

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

CayenneContext()
Creates a new CayenneContext with no channel and disabled graph events.

CayenneContext(DataChannel channel)
Creates a new CayenneContext, initializing it with a channel instance.

CayenneContext(DataChannel channel, boolean changeEventsEnabled, boolean syncEventsEnabled)
Creates a new CayenneContext, initializing it with a channel.

Method Summary

void	commitChanges() Commits changes to uncommitted objects.
void	commitChangesToParent() Flushes all changes to objects in this context to the parent DataChannel.
ObjectContext	createChildContext() Creates and returns a new child ObjectContext.
Collection<?>	deletedObjects() Returns a collection of objects that are registered with this ObjectContext and have a state PersistenceState.DELETED
void	deleteObject(Object object) Deletes an object locally, scheduling it for future deletion from the external data store.
void	deleteObjects(Collection<?> objects) Deletes a collection of objects by repeatedly calling deleteObject safely (avoiding a concurrent modification exception).
EntityResolver	getEntityResolver() Returns an EntityResolver that provides mapping information needed for CayenneContext operation.
GraphManager	getGraphManager() Returns GraphManager that manages object graph associated with this context.
boolean	hasChanges() Returns true if there are any modified, deleted or new objects registered with this CayenneContext, false otherwise.
boolean	isChangeEventsEnabled() Returns true if this context posts individual object modification events.
boolean	isLifecycleEventsEnabled() Returns true if this context posts lifecycle events.
Persistent	localObject(ObjectId id, Object prototype) Converts a list of Persistent objects registered in some other ObjectContext to a list of objects local to this ObjectContext.
Collection<?>	modifiedObjects() Returns a collection of objects that are registered with this ObjectContext and have a state PersistenceState.MODIFIED
<T> T	newObject(Class<T> persistentClass) Creates and registers a new Persistent object instance.
Collection<?>	newObjects() Returns a collection of objects that are registered with this ObjectContext and have a state PersistenceState.NEW
protected GraphDiff	onContextFlush(ObjectContext originatingContext, GraphDiff changes, boolean cascade)
QueryResponse	onQuery(ObjectContext context, Query query) Executes a query, using provided context to register persistent objects if query returns any objects.
QueryResponse	performGenericQuery(Query query) Executes any kind of query providing the result in a form of QueryResponse.
List	performQuery(Query query) Runs a query, returning result as list.
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.
void	registerNewObject(Object object) Registers a transient object with the context.
void	rollbackChanges() Resets all uncommitted changes made to the objects in this ObjectContext, cascading rollback operation all the way through the stack.
void	rollbackChangesLocally() Resets all uncommitted changes made to the objects in this ObjectContext.
void	setChannel(DataChannel channel) Sets the context channel, setting up a listener for channel events.
void	setEntityResolver(EntityResolver entityResolver)
Collection<?>	uncommittedObjects() Returns a collection of MODIFIED, DELETED or NEW objects.

Methods inherited from class org.apache.cayenne.BaseContext

bindThreadObjectContext, fireDataChannelChanged, fireDataChannelCommitted, fireDataChannelRolledback, getChannel, getEventManager, getQueryCache, getThreadObjectContext, getUserProperties, getUserProperty, injectInitialValue, invalidateObjects, onSync, prepareForAccess, prepareForAccess, setQueryCache, setUserProperty

Methods inherited from class java.lang.Object

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

Field Detail

entityResolver

protected EntityResolver entityResolver

Constructor Detail

CayenneContext

public CayenneContext()

Creates a new CayenneContext with no channel and disabled graph events.

CayenneContext

public CayenneContext(DataChannel channel)

Creates a new CayenneContext, initializing it with a channel instance. CayenneContext created using this constructor WILL NOT broadcast graph change events.

CayenneContext

public CayenneContext(DataChannel channel,
                      boolean changeEventsEnabled,
                      boolean syncEventsEnabled)

Creates a new CayenneContext, initializing it with a channel. If graphEventsEnabled is true, this context will broadcast GraphEvents using ObjectContext.GRAPH_CHANGE_SUBJECT.

Method Detail

setChannel

public void setChannel(DataChannel channel)

Sets the context channel, setting up a listener for channel events.

isChangeEventsEnabled

public boolean isChangeEventsEnabled()

Returns true if this context posts individual object modification events. Subject used for these events is ObjectContext.GRAPH_CHANGED_SUBJECT.

isLifecycleEventsEnabled

public boolean isLifecycleEventsEnabled()

Returns true if this context posts lifecycle events. Subjects used for these events are ObjectContext.GRAPH_COMMIT_STARTED_SUBJECT, ObjectContext.GRAPH_COMMITTED_SUBJECT, ObjectContext.GRAPH_COMMIT_ABORTED_SUBJECT, ObjectContext.GRAPH_ROLLEDBACK_SUBJECT. .

getEntityResolver

public EntityResolver getEntityResolver()

Returns an EntityResolver that provides mapping information needed for CayenneContext operation. If EntityResolver is not set, this method would obtain and cache one from the underlying DataChannel.

Specified by:

getEntityResolver in interface DataChannel

Specified by:

getEntityResolver in interface ObjectContext

Specified by:

getEntityResolver in class BaseContext

setEntityResolver

public void setEntityResolver(EntityResolver entityResolver)

getGraphManager

public GraphManager getGraphManager()

Description copied from interface: ObjectContext

Returns GraphManager that manages object graph associated with this context.

Specified by:

getGraphManager in interface ObjectContext

Specified by:

getGraphManager in class BaseContext

commitChanges

public void commitChanges()

Commits changes to uncommitted objects. First checks if there are changes in this context and if any changes are detected, sends a commit message to remote Cayenne service via an internal instance of CayenneConnector.

Specified by:

commitChanges in interface ObjectContext

Specified by:

commitChanges in class BaseContext

commitChangesToParent

public 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

Specified by:

commitChangesToParent in class BaseContext

rollbackChanges

public 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

Specified by:

rollbackChanges in class BaseContext

rollbackChangesLocally

public 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

Specified by:

rollbackChangesLocally in class BaseContext

deleteObject

public void deleteObject(Object object)

Deletes an object locally, scheduling it for future deletion from the external data store.

Specified by:

deleteObject in interface ObjectContext

Specified by:

deleteObject in class BaseContext

deleteObjects

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

Description copied from interface: ObjectContext

Deletes a collection of objects by repeatedly calling deleteObject safely (avoiding a concurrent modification exception).

Throws:

DeleteDenyException

newObject

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

Creates and registers a new Persistent object instance.

Specified by:

newObject in interface ObjectContext

Specified by:

newObject in class BaseContext

registerNewObject

public 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

Specified by:

registerNewObject in class BaseContext

Parameters:

object - new object that needs to be made persistent.

Since:

3.0

performQuery

public List performQuery(Query query)

Runs a query, returning result as list.

Specified by:

performQuery in interface ObjectContext

Specified by:

performQuery in class BaseContext

performGenericQuery

public 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

Specified by:

performGenericQuery in class BaseContext

onQuery

public QueryResponse onQuery(ObjectContext context,
                             Query query)

Description copied from interface: DataChannel

Executes a query, using provided context to register persistent objects if query returns any objects.

Parameters:

context - an ObjectContext that originated the query, used to register result objects.

Returns:

a generic response object that encapsulates result of the execution.

localObject

public Persistent localObject(ObjectId id,
                              Object prototype)

Converts a list of Persistent objects registered in some other ObjectContext to a list of objects local to this ObjectContext.

Current limitation: all objects in the source list must be either in COMMITTED or in HOLLOW state.

Specified by:

localObject in interface ObjectContext

Specified by:

localObject in class BaseContext

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

Specified by:

propertyChanged in class BaseContext

uncommittedObjects

public Collection<?> uncommittedObjects()

Description copied from interface: ObjectContext

Returns a collection of MODIFIED, DELETED or NEW objects.

Specified by:

uncommittedObjects in interface ObjectContext

Specified by:

uncommittedObjects in class BaseContext

deletedObjects

public 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

Specified by:

deletedObjects in class BaseContext

modifiedObjects

public 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

Specified by:

modifiedObjects in class BaseContext

newObjects

public 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

Specified by:

newObjects in class BaseContext

createChildContext

public ObjectContext createChildContext()

Creates and returns a new child ObjectContext.

Since:

3.0

onContextFlush

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

Specified by:

onContextFlush in class BaseContext

hasChanges

public boolean hasChanges()

Returns true if there are any modified, deleted or new objects registered with this CayenneContext, false otherwise.