Interface COM.odi.odmg.Collection

public interface Collection
extends IPersistent, Cloneable

The Collection interface is the super interface of all collection interfaces. This interface encapsulates the operations on a collection.

Unlike java.lang.Vector, a search for an object in a collection uses == for comparison, rather than Object.equals(). For example, Collection.remove(Object o) removes the object o itself, and not any other object that equals o.

All methods throw the following exceptions:

COM.odi.odmg.TransactionNotInProgressException If there is no transaction in progress.

COM.odi.ObjectStoreException If the current thread is not associated with a transaction or if the instance in question is not associated with the current thread.

Methods that modify persistent objects throw this exception:

COM.odi.odmg.DatabaseIsReadOnlyException If there is a readonly transaction in progress or if the database is open for readonly.

See Also:: Set, List, Bag, VArray

add(Object): Equivalent to the ODMG method insert_element().
contains(Object): Equivalent to the ODMG method boolean contains_element().
elements(): Equivalent to the ODMG method Iterator create_Iterator().
existsElement(String): This is an ODMG OQL method that is not supported.
isEmpty(): Equivalent to the ODMG method boolean is_Empty().
query(String): This is an ODMG OQL method that is not supported.
remove(Object): Equivalent to the ODMG method void remove_element().
select(String): This is an ODMG OQL method that is not supported.
selectElement(String): This is an ODMG OQL method that is not supported.
size(): Equivalent to the ODMG method long cardinality().

size

  public abstract int size()

Equivalent to the ODMG method long cardinality().

Returns:: Returns the size of this collection.

isEmpty

  public abstract boolean isEmpty()

Equivalent to the ODMG method boolean is_Empty().

Returns:: Returns true if this collection is empty, and false otherwise.

add

  public abstract void add(Object obj)

Equivalent to the ODMG method insert_element().

Parameters:: obj - The object to be added.
Throws: ObjectNotExportedException: If the collection and the object being added are in different segments and the object is not exported.
Throws: ObjectNotPersistenceCapableException: If the object is not persistence-capable.

remove

  public abstract Object remove(Object obj)

Equivalent to the ODMG method void remove_element().

Parameters:: obj - The object to be removed.
Returns:: Returns the object that was removed from the collection. If no object is removed, returns null.

contains

  public abstract boolean contains(Object obj)

Equivalent to the ODMG method boolean contains_element().

Parameters:: obj - The object to find in the collection.
Returns:: Returns true if the object is contained in this collection, and false otherwise.

elements

  public abstract Enumeration elements()

Equivalent to the ODMG method Iterator create_Iterator().

Returns:: Returns an enumeration of the elements in the collection.

selectElement

  public abstract Object selectElement(String predicate)

This is an ODMG OQL method that is not supported.

Throws: ODMGException: Always.

select

  public abstract Enumeration select(String predicate)

This is an ODMG OQL method that is not supported.

Throws: ODMGException: Always.

query

  public abstract Collection query(String predicate)

This is an ODMG OQL method that is not supported.

Throws: ODMGException: Always.

existsElement

  public abstract boolean existsElement(String predicate)

This is an ODMG OQL method that is not supported.

Throws: ODMGException: Always.