org.odmg
Interface DBag

All Superinterfaces:

Collection, DCollection, Iterable

All Known Implementing Classes:

DBagImpl

public interface DBag
extends DCollection

This interface defines the operations associated with an ODMG bag collection. All of the operations defined by the JavaSoft Collection interface are supported by an ODMG implementation of DBag, the exception UnsupportedOperationException is not thrown when a call is made to any of the Collection methods.

Version:

ODMG 3.0

Author:

David Jordan (as Java Editor of the Object Data Management Group)

Method Summary

DBag	difference(DBag otherBag) A new DBag instance is created that contains the difference of this object and the DBag instance referenced by otherBag.
DBag	intersection(DBag otherBag) A new DBag instance is created that contains the intersection of this object and the DBag referenced by otherBag.
int	occurrences(Object obj) This method returns the number of occurrences of the object obj in the DBag collection.
DBag	union(DBag otherBag) A new DBag instance is created that is the union of this object and otherBag.

Methods inherited from interface org.odmg.DCollection

existsElement, query, select, selectElement

Methods inherited from interface java.util.Collection

add, addAll, clear, contains, containsAll, equals, hashCode, isEmpty, iterator, remove, removeAll, retainAll, size, toArray, toArray

Method Detail

union

DBag union(DBag otherBag)

A new DBag instance is created that is the union of this object and otherBag. This method is similar to the addAll method in Collection, except that this method creates a new collection and addAll modifies the object to contain the result.

Parameters:

otherBag - The other bag to use in the union operation.

Returns:

A DBag instance that contains the union of this object and otherBag.

intersection

DBag intersection(DBag otherBag)

A new DBag instance is created that contains the intersection of this object and the DBag referenced by otherBag. This method is similar to the retainAll method in Collection, except that this method creates a new collection and retainAll modifies the object to contain the result.

Parameters:

otherBag - The other bag to use in creating the intersection.

Returns:

A DBag instance that contains the intersection of this object and otherBag.

difference

DBag difference(DBag otherBag)

A new DBag instance is created that contains the difference of this object and the DBag instance referenced by otherBag. This method is similar to the removeAll method in Collection, except that this method creates a new collection and removeAll modifies the object to contain the result.

Parameters:

otherBag - The other bag to use in creating the difference.

Returns:

A DBag instance that contains the elements of this object minus the elements in otherBag.

occurrences

int occurrences(Object obj)

This method returns the number of occurrences of the object obj in the DBag collection.

Parameters:

obj - The value that may have elements in the collection.

Returns:

The number of occurrences of obj in this collection.