javax.jdo.Extent - JDO interface
javax.jdo
Interface Extent<E>
- Superinterfaces:
-
Iterable<E>
Instances of the
Extent class represent the entire collection of instances in the data store of the candidate class or interface possibly including its subclasses or subinterfaces.
The Extent instance has two possible uses:
- to iterate all instances of a particular class or interface
- to execute a
Queryin the data store over all instances of a particular class or interface
- Since:
- JDO 1.0
void
close(Iterator<E> it)
Close an
Iterator associated with this
Extent instance.
Iterators closed by this method will return
false to
hasNext() and will throw
NoSuchElementException on
next(). The
Extent instance can still be used as a parameter of
Query.setExtent, and to get an
Iterator.
- Parameters:
-
it- anIteratorobtained by the methoditerator()on thisExtentinstance.
- Since:
- JDO 1.0
void
closeAll()
Close all
Iterators associated with this
Extent instance.
Iterators closed by this method will return
false to
hasNext() and will throw
NoSuchElementException on
next(). The
Extent instance can still be used as a parameter of
Query.setExtent, and to get an
Iterator.
- Since:
- JDO 1.0
Class<E>
getCandidateClass()
An
Extent contains all instances of a particular class or interface in the data store; this method returns the
Class of the instances represented by this Extent.
- Returns:
-
the
Classof instances of thisExtent.
- Since:
- JDO 1.0
Get the fetch plan associated with this Extent.
- Returns:
- the fetch plan
- Since:
- JDO 2.0
An
Extent is managed by a
PersistenceManager; this method gives access to the owning
PersistenceManager.
- Returns:
-
the owning
PersistenceManager
- Since:
- JDO 1.0
boolean
hasSubclasses()
Returns whether this
Extent was defined to contain subclasses.
- Returns:
-
true if this
Extentwas defined to contain instances that are of a subclass type.
- Since:
- JDO 1.0
Iterator<T>
iterator()
Iterator<E>
iterator()
Returns an iterator over all the instances in the
Extent. The behavior of the returned iterator might depend on the setting of the
ignoreCache flag in the owning
PersistenceManager.
- Returns:
-
an iterator over all instances in the
Extent
- Since:
- JDO 1.0
