com.sleepycat.collections
Class StoredCollection

java.lang.Object
  |
  +--com.sleepycat.collections.StoredContainer
        |
        +--com.sleepycat.collections.StoredCollection

All Implemented Interfaces:

Cloneable, Collection

Direct Known Subclasses:

StoredEntrySet, StoredKeySet, StoredValueSet

public abstract class StoredCollection

extends StoredContainer

implements Collection

A abstract base class for all stored collections. This class, and its base class StoredContainer, provide implementations of most methods in the Collection interface. Other methods, such as Collection.add(java.lang.Object) and Collection.remove(java.lang.Object), are provided by concrete classes that extend this class.

Note that this class does not conform to the standard Java collections interface in the following ways:

• The StoredContainer.size() method always throws UnsupportedOperationException because, for performance reasons, databases do not maintain their total record count.
• All iterators must be explicitly closed using StoredIterator.close() or StoredIterator.close(java.util.Iterator) to release the underlying database cursor resources.

In addition, this class provides the following methods for stored collections only. Note that the use of these methods is not compatible with the standard Java collections interface.

• iterator(boolean)
• join(com.sleepycat.collections.StoredContainer[], java.lang.Object[], com.sleepycat.je.JoinConfig)
• toList()

Author:

Mark Hayes

Method Summary

boolean	addAll(Collection coll) Adds all of the elements in the specified collection to this collection (optional operation).
boolean	containsAll(Collection coll) Returns true if this collection contains all of the elements in the specified collection.
boolean	equals(Object other) Compares the specified object with this collection for equality.
Iterator	iterator() Returns an iterator over the elements in this collection.
StoredIterator	iterator(boolean writeAllowed) Returns a read or read-write iterator over the elements in this collection.
StoredIterator	join(StoredContainer[] indices, Object[] indexKeys, JoinConfig joinConfig) Returns an iterator representing an equality join of the indices and index key values specified.
boolean	removeAll(Collection coll) Removes all this collection's elements that are also contained in the specified collection (optional operation).
boolean	retainAll(Collection coll) Retains only the elements in this collection that are contained in the specified collection (optional operation).
Object[]	toArray() Returns an array of all the elements in this collection.
Object[]	toArray(Object[] a) Returns an array of all the elements in this collection whose runtime type is that of the specified array.
List	toList() Returns a copy of this collection as an ArrayList.
String	toString() Converts the collection to a string representation for debugging.

Methods inherited from class com.sleepycat.collections.StoredContainer

areDuplicatesAllowed, areDuplicatesOrdered, areKeysRenumbered, clear, isDirtyRead, isDirtyReadAllowed, isEmpty, isOrdered, isSecondary, isTransactional, isWriteAllowed, size

Methods inherited from class java.lang.Object

getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection

add, clear, contains, hashCode, isEmpty, remove, size

Method Detail

iterator

public Iterator iterator()

Returns an iterator over the elements in this collection. The iterator will be read-only if the collection is read-only. This method conforms to the Collection.iterator() interface.

Specified by:

iterator in interface Collection

Returns:

a StoredIterator for this collection.

Throws:

RuntimeExceptionWrapper - if a DatabaseException is thrown.

See Also:

StoredContainer.isWriteAllowed()

iterator

public StoredIterator iterator(boolean writeAllowed)

Returns a read or read-write iterator over the elements in this collection. This method does not exist in the standard Collection interface.

Parameters:

writeAllowed - is true to open a read-write iterator or false to open a read-only iterator. If the collection is read-only the iterator will always be read-only.

Returns:

a StoredIterator for this collection.

Throws:

IllegalStateException - if writeAllowed is true but the collection is read-only.

RuntimeExceptionWrapper - if a DatabaseException is thrown.

See Also:

StoredContainer.isWriteAllowed()

toArray

public Object[] toArray()

Returns an array of all the elements in this collection. This method conforms to the Collection.toArray() interface.

Specified by:

toArray in interface Collection

Throws:

RuntimeExceptionWrapper - if a DatabaseException is thrown.

toArray

public Object[] toArray(Object[] a)

Returns an array of all the elements in this collection whose runtime type is that of the specified array. This method conforms to the Collection.toArray(Object[]) interface.

Specified by:

toArray in interface Collection

Throws:

RuntimeExceptionWrapper - if a DatabaseException is thrown.

containsAll

public boolean containsAll(Collection coll)

Returns true if this collection contains all of the elements in the specified collection. This method conforms to the Collection.containsAll(java.util.Collection) interface.

Specified by:

containsAll in interface Collection

Throws:

RuntimeExceptionWrapper - if a DatabaseException is thrown.

addAll

public boolean addAll(Collection coll)

Adds all of the elements in the specified collection to this collection (optional operation). This method calls the Collection.add(Object) method of the concrete collection class, which may or may not be supported. This method conforms to the Collection.addAll(java.util.Collection) interface.

Specified by:

addAll in interface Collection

Throws:

UnsupportedOperationException - if the collection is read-only, or if the collection is indexed, or if the add method is not supported by the concrete collection.

RuntimeExceptionWrapper - if a DatabaseException is thrown.

removeAll

public boolean removeAll(Collection coll)

Removes all this collection's elements that are also contained in the specified collection (optional operation). This method conforms to the Collection.removeAll(java.util.Collection) interface.

Specified by:

removeAll in interface Collection

Throws:

UnsupportedOperationException - if the collection is read-only.

RuntimeExceptionWrapper - if a DatabaseException is thrown.

retainAll

public boolean retainAll(Collection coll)

Retains only the elements in this collection that are contained in the specified collection (optional operation). This method conforms to the Collection.removeAll(java.util.Collection) interface.

Specified by:

retainAll in interface Collection

Throws:

UnsupportedOperationException - if the collection is read-only.

RuntimeExceptionWrapper - if a DatabaseException is thrown.

equals

public boolean equals(Object other)

Compares the specified object with this collection for equality. A value comparison is performed by this method and the stored values are compared rather than calling the equals() method of each element. This method conforms to the Collection.equals(java.lang.Object) interface.

Specified by:

equals in interface Collection

Overrides:

equals in class Object

Throws:

RuntimeExceptionWrapper - if a DatabaseException is thrown.

toList

public List toList()

Returns a copy of this collection as an ArrayList. This is the same as toArray() but returns a collection instead of an array.

Returns:

an ArrayList containing a copy of all elements in this collection.

Throws:

RuntimeExceptionWrapper - if a DatabaseException is thrown.

toString

public String toString()

Converts the collection to a string representation for debugging. WARNING: All elements will be converted to strings and returned and therefore the returned string may be very large.

Overrides:

toString in class Object

Returns:

the string representation.

Throws:

RuntimeExceptionWrapper - if a DatabaseException is thrown.

join

public StoredIterator join(StoredContainer[] indices,
                           Object[] indexKeys,
                           JoinConfig joinConfig)

Returns an iterator representing an equality join of the indices and index key values specified. This method does not exist in the standard Collection interface.

The returned iterator supports only the two methods: hasNext() and next(). All other methods will throw UnsupportedOperationException.

Parameters:

indices - is an array of indices with elements corresponding to those in the indexKeys array.

indexKeys - is an array of index key values identifying the elements to be selected.

joinConfig - is the join configuration, or null to use the default configuration.

Returns:

an iterator over the elements in this collection that match all specified index key values.

Throws:

IllegalArgumentException - if this collection is indexed or if a given index does not have the same store as this collection.

RuntimeExceptionWrapper - if a DatabaseException is thrown.