org.apache.cayenne
Class BaseContext

java.lang.Object
  extended by org.apache.cayenne.BaseContext
All Implemented Interfaces:
Serializable, DataChannel, ObjectContext
Direct Known Subclasses:
CayenneContext, DataContext

public abstract class BaseContext
extends Object
implements ObjectContext, DataChannel

A common base superclass for Cayenne ObjectContext implementors.

Since:
3.0
See Also:
Serialized Form

Field Summary
protected  DataChannel channel
           
protected  EntityResolver entityResolver
           
protected  ObjectContextGraphAction graphAction
          Graph action that handles property changes
static String QUERY_CACHE_INJECTION_KEY
           
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.
 
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
protected BaseContext()
           
 
Method Summary
protected  void attachToChannel(DataChannel channel)
          Initializes a DataChannel for this context, setting internal state using information from the
protected  void attachToRuntime(Injector injector)
          Attaches this context to the Cayenne runtime 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().
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 an object for deletion on the next commit of this context.
 void deleteObjects(Collection<?> objects)
          Deletes a collection of objects by repeatedly calling deleteObject safely (avoiding a concurrent modification exception).
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 an EntityResolver instance that contains runtime mapping information.
 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.
abstract  Persistent localObject(ObjectId id, Object prototype)
          Returns an object local to this ObjectContext and matching the ObjectId.
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 syncronization.
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.
 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.
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.ObjectContext
createChildContext, hasChanges
 
Methods inherited from interface org.apache.cayenne.DataChannel
onQuery
 

Field Detail

QUERY_CACHE_INJECTION_KEY

public static final String QUERY_CACHE_INJECTION_KEY
See Also:
Constant Field Values

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

graphAction

protected ObjectContextGraphAction graphAction
Graph action that handles property changes

Since:
3.1

userProperties

protected 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 Cayenne runtime whose Injector is passed as an argument to this method.

Since:
3.1

attachToChannel

protected void attachToChannel(DataChannel channel)
Initializes a DataChannel for this context, setting internal state using information from the

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

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: DataChannel
Returns an EntityResolver instance that contains runtime mapping information.

Specified by:
getEntityResolver in interface DataChannel
Specified by:
getEntityResolver in interface ObjectContext

setEntityResolver

public void setEntityResolver(EntityResolver entityResolver)
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

localObject

public abstract Persistent localObject(ObjectId id,
                                       Object prototype)
Description copied from interface: ObjectContext
Returns an object local to this ObjectContext and matching the ObjectId. If prototype is not null, local object is refreshed with the prototype values.

This method can do both "mapping" (i.e. finding an object with the same id in this context) and "synchronization" (i.e. updating the state of the found object with the state of the prototype object).

Specified by:
localObject 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

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 syncronization.

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
See Also:
RefreshQuery

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


deleteObject

public void deleteObject(Object object)
Schedules an object for deletion on the next commit of this context. Object's persistence state is changed to PersistenceState.DELETED; objects related to this object are processed according to delete rules, i.e. relationships can be unset ("nullify" rule), deletion operation is cascaded (cascade rule).

Specified by:
deleteObject in interface ObjectContext
Parameters:
object - a persistent object that we want to delete.
Throws:
DeleteDenyException - if a DENY delete rule is applicable for object deletion.
NullPointerException - if object is null.

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).

Specified by:
deleteObjects in interface ObjectContext
Throws:
DeleteDenyException


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