Berkeley DB
version 4.8.30

com.sleepycat.collections
Class StoredKeySet<K>

java.lang.Object
  extended by com.sleepycat.collections.StoredContainer
      extended by com.sleepycat.collections.StoredCollection<K>
          extended by com.sleepycat.collections.StoredKeySet<K>
All Implemented Interfaces:
Cloneable, Iterable<K>, Collection<K>, Set<K>
Direct Known Subclasses:
StoredSortedKeySet

public class StoredKeySet<K>
extends StoredCollection<K>
implements Set<K>

The Set returned by Map.keySet() and which can also be constructed directly if a Map is not needed. Since this collection is a set it only contains one element for each key, even when duplicates are allowed. Key set iterators are therefore particularly useful for enumerating the unique keys of a store or index that allows duplicates.


Field Summary
 
Fields inherited from class com.sleepycat.collections.StoredCollection
DEFAULT_ITERATOR_BLOCK_SIZE
 
Constructor Summary
StoredKeySet(Database database, EntryBinding<K> keyBinding, boolean writeAllowed)
          Creates a key set view of a Database.
 
Method Summary
 boolean add(K key)
          Adds the specified key to this set if it is not already present (optional operation).
 boolean contains(Object key)
          Returns true if this set contains the specified key.
 boolean remove(Object key)
          Removes the specified key from this set if it is present (optional operation).
 
Methods inherited from class com.sleepycat.collections.StoredCollection
addAll, containsAll, equals, getIteratorBlockSize, hashCode, iterator, iterator, join, removeAll, retainAll, setIteratorBlockSize, size, storedIterator, storedIterator, toArray, toArray, toList, toString
 
Methods inherited from class com.sleepycat.collections.StoredContainer
areDuplicatesAllowed, areDuplicatesOrdered, areKeyRangesAllowed, areKeysRenumbered, clear, getCursorConfig, isEmpty, isOrdered, isSecondary, isTransactional, isWriteAllowed
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface java.util.Set
addAll, clear, containsAll, equals, hashCode, isEmpty, iterator, removeAll, retainAll, size, toArray, toArray
 

Constructor Detail

StoredKeySet

public StoredKeySet(Database database,
                    EntryBinding<K> keyBinding,
                    boolean writeAllowed)
Creates a key set view of a Database.

Parameters:
database - is the Database underlying the new collection.
keyBinding - is the binding used to translate between key buffers and key objects.
writeAllowed - is true to create a read-write collection or false to create a read-only collection.
Throws:
IllegalArgumentException - if formats are not consistently defined or a parameter is invalid.
RuntimeExceptionWrapper - if a DatabaseException is thrown.
Method Detail

add

public boolean add(K key)
Adds the specified key to this set if it is not already present (optional operation). When a key is added the value in the underlying data store will be empty. This method conforms to the Set.add(E) interface.

Specified by:
add in interface Collection<K>
Specified by:
add in interface Set<K>
Throws:
UnsupportedOperationException - if the collection is indexed, or if the collection is read-only.
RuntimeExceptionWrapper - if a DatabaseException is thrown.

remove

public boolean remove(Object key)
Removes the specified key from this set if it is present (optional operation). If duplicates are allowed, this method removes all duplicates for the given key. This method conforms to the Set.remove(java.lang.Object) interface.

Specified by:
remove in interface Collection<K>
Specified by:
remove in interface Set<K>
Throws:
UnsupportedOperationException - if the collection is read-only.
RuntimeExceptionWrapper - if a DatabaseException is thrown.

contains

public boolean contains(Object key)
Returns true if this set contains the specified key. This method conforms to the Set.contains(java.lang.Object) interface.

Specified by:
contains in interface Collection<K>
Specified by:
contains in interface Set<K>
Throws:
RuntimeExceptionWrapper - if a DatabaseException is thrown.

Berkeley DB
version 4.8.30

Copyright (c) 1996-2009 Oracle. All rights reserved.