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java.lang.Objectcom.sleepycat.collections.StoredContainer
com.sleepycat.collections.StoredCollection
com.sleepycat.collections.StoredKeySet
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.
Note that this class does not conform to the standard Java collections interface in the following ways:
StoredContainer.size()
method always throws UnsupportedOperationException
because, for performance reasons, databases do not maintain their total
record count.StoredIterator.close()
or StoredIterator.close(java.util.Iterator)
to release the underlying database cursor resources.
Constructor Summary | |
StoredKeySet(Database database, EntryBinding keyBinding,
boolean writeAllowed) Creates a key set view of a Database . |
Method Summary | |
boolean |
add(Object 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,
hashCode,
iterator,
iterator,
join,
removeAll,
retainAll,
toArray,
toArray,
toList,
toString |
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, 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 |
public StoredKeySet(Database database, EntryBinding keyBinding, boolean writeAllowed)
Database
.
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.
IllegalArgumentException
-
if formats are not consistently defined or a parameter is invalid.
RuntimeExceptionWrapper
- if a DatabaseException
is thrown.
Method Detail |
public boolean add(Object key)
Set.add(java.lang.Object)
interface.
add
in interface Set
UnsupportedOperationException
- if the collection is indexed, or if the collection is read-only.
RuntimeExceptionWrapper
- if a DatabaseException
is thrown.
public boolean remove(Object key)
Set.remove(java.lang.Object)
interface.
remove
in interface Set
UnsupportedOperationException
- if the collection is read-only.
RuntimeExceptionWrapper
- if a DatabaseException
is thrown.
public boolean contains(Object key)
Set.contains(java.lang.Object)
interface.
contains
in interface Set
RuntimeExceptionWrapper
- if a DatabaseException
is thrown.
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