Package com.sleepycat.collections

Class StoredKeySet<K>

java.lang.Object

com.sleepycat.collections.StoredContainer

com.sleepycat.collections.StoredCollection<K>

com.sleepycat.collections.StoredKeySet<K>

All Implemented Interfaces:

java.lang.Cloneable, java.lang.Iterable<K>, java.util.Collection<K>, java.util.Set<K>

Direct Known Subclasses:

StoredSortedKeySet

public class StoredKeySet<K>
extends StoredCollection<K>
implements java.util.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

Constructors

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

Method Summary

Modifier and Type	Method	Description
boolean	add(K key)	Adds the specified key to this set if it is not already present (optional operation).
boolean	contains(java.lang.Object key)	Returns true if this set contains the specified key.
boolean	remove(java.lang.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.Collection

parallelStream, removeIf, stream, toArray

Methods inherited from interface java.lang.Iterable

forEach

Methods inherited from interface java.util.Set

addAll, clear, containsAll, equals, hashCode, isEmpty, iterator, removeAll, retainAll, size, spliterator, 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:

java.lang.IllegalArgumentException - if formats are not consistently defined or a parameter is invalid.

RuntimeExceptionWrapper - if a checked exception is thrown, including a DatabaseException on BDB (C Edition).

Method Detail

add

public boolean add(K key)

Adds the specified key to this set if it is not already present (optional operation). This method conforms to the Set.add(E) interface.

WARNING: When a key is added the value in the underlying data store will be empty, i.e., the byte array will be zero length. Such a record cannot be accessed using the Map interface unless the value binding supports zero length byte arrays.

Specified by:

add in interface java.util.Collection<K>

Specified by:

add in interface java.util.Set<K>

Throws:

java.lang.UnsupportedOperationException - if the collection is indexed, or if the collection is read-only.

RuntimeExceptionWrapper - if a checked exception is thrown, including a DatabaseException on BDB (C Edition).

remove

public boolean remove(java.lang.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 java.util.Collection<K>

Specified by:

remove in interface java.util.Set<K>

Throws:

java.lang.UnsupportedOperationException - if the collection is read-only.

RuntimeExceptionWrapper - if a checked exception is thrown, including a DatabaseException on BDB (C Edition).

contains

public boolean contains(java.lang.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 java.util.Collection<K>

Specified by:

contains in interface java.util.Set<K>

Throws:

RuntimeExceptionWrapper - if a checked exception is thrown, including a DatabaseException on BDB (C Edition).