Package com.sleepycat.collections

Class StoredSortedKeySet<K>

java.lang.Object

com.sleepycat.collections.StoredContainer

com.sleepycat.collections.StoredCollection<K>

com.sleepycat.collections.StoredKeySet<K>

com.sleepycat.collections.StoredSortedKeySet<K>

All Implemented Interfaces:

Cloneable, Iterable<K>, Collection<K>, SequencedCollection<K>, SequencedSet<K>, Set<K>, SortedSet<K>

public class StoredSortedKeySet<K>
extends StoredKeySet<K>
implements SortedSet<K>

The SortedSet 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.

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

• headSet(Object, boolean)
• tailSet(Object, boolean)
• subSet(Object, boolean, Object, boolean)

Field Summary

Fields inherited from class com.sleepycat.collections.StoredCollection

DEFAULT_ITERATOR_BLOCK_SIZE

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method	Description
Comparator<? super K>	comparator()	Returns null since comparators are not supported.
K	first()	Returns the first (lowest) element currently in this sorted set.
SortedSet<K>	headSet(K toKey)	Returns a view of the portion of this sorted set whose elements are strictly less than toKey.
SortedSet<K>	headSet(K toKey, boolean toInclusive)	Returns a view of the portion of this sorted set whose elements are strictly less than toKey, optionally including toKey.
K	last()	Returns the last (highest) element currently in this sorted set.
SortedSet<K>	subSet(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive)	Returns a view of the portion of this sorted set whose elements are strictly greater than fromKey and strictly less than toKey, optionally including fromKey and toKey.
SortedSet<K>	subSet(K fromKey, K toKey)	Returns a view of the portion of this sorted set whose elements range from fromKey, inclusive, to toKey, exclusive.
SortedSet<K>	tailSet(K fromKey)	Returns a view of the portion of this sorted set whose elements are greater than or equal to fromKey.
SortedSet<K>	tailSet(K fromKey, boolean fromInclusive)	Returns a view of the portion of this sorted set whose elements are strictly greater than fromKey, optionally including fromKey.

Methods inherited from class com.sleepycat.collections.StoredKeySet

add, contains, remove

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

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

Methods inherited from interface java.util.SortedSet

addFirst, addLast, getFirst, getLast, removeFirst, removeLast, reversed, spliterator

Constructor Details

StoredSortedKeySet

public StoredSortedKeySet(Database database,
 EntryBinding<K> keyBinding,
 boolean writeAllowed)

Creates a sorted 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 checked exception is thrown, including a DatabaseException on BDB (C edition).

Method Details

comparator

public Comparator<? super K> comparator()

Returns null since comparators are not supported. The natural ordering of a stored collection is data byte order, whether the data classes implement the Comparable interface or not. This method does not conform to the SortedSet.comparator() interface.

Specified by:

comparator in interface SortedSet<K>

Returns:

null.

first

public K first()

Returns the first (lowest) element currently in this sorted set. This method conforms to the SortedSet.first() interface.

Specified by:

first in interface SortedSet<K>

Returns:

the first element.

Throws:

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

last

public K last()

Returns the last (highest) element currently in this sorted set. This method conforms to the SortedSet.last() interface.

Specified by:

last in interface SortedSet<K>

Returns:

the last element.

Throws:

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

headSet

public SortedSet<K> headSet(K toKey)

Returns a view of the portion of this sorted set whose elements are strictly less than toKey. This method conforms to the SortedSet.headSet(E) interface.

Note that the return value is a StoredCollection and must be treated as such; for example, its iterators must be explicitly closed.

Specified by:

headSet in interface SortedSet<K>

Parameters:

toKey - is the upper bound.

Returns:

the subset.

Throws:

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

headSet

public SortedSet<K> headSet(K toKey,
 boolean toInclusive)

Returns a view of the portion of this sorted set whose elements are strictly less than toKey, optionally including toKey. This method does not exist in the standard SortedSet interface.

Note that the return value is a StoredCollection and must be treated as such; for example, its iterators must be explicitly closed.

Parameters:

toKey - is the upper bound.

toInclusive - is true to include toKey.

Returns:

the subset.

Throws:

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

tailSet

public SortedSet<K> tailSet(K fromKey)

Returns a view of the portion of this sorted set whose elements are greater than or equal to fromKey. This method conforms to the SortedSet.tailSet(E) interface.

Note that the return value is a StoredCollection and must be treated as such; for example, its iterators must be explicitly closed.

Specified by:

tailSet in interface SortedSet<K>

Parameters:

fromKey - is the lower bound.

Returns:

the subset.

Throws:

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

tailSet

public SortedSet<K> tailSet(K fromKey,
 boolean fromInclusive)

Returns a view of the portion of this sorted set whose elements are strictly greater than fromKey, optionally including fromKey. This method does not exist in the standard SortedSet interface.

Note that the return value is a StoredCollection and must be treated as such; for example, its iterators must be explicitly closed.

Parameters:

fromKey - is the lower bound.

fromInclusive - is true to include fromKey.

Returns:

the subset.

Throws:

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

subSet

public SortedSet<K> subSet(K fromKey,
 K toKey)

Returns a view of the portion of this sorted set whose elements range from fromKey, inclusive, to toKey, exclusive. This method conforms to the SortedSet.subSet(E, E) interface.

Note that the return value is a StoredCollection and must be treated as such; for example, its iterators must be explicitly closed.

Specified by:

subSet in interface SortedSet<K>

Parameters:

fromKey - is the lower bound.

toKey - is the upper bound.

Returns:

the subset.

Throws:

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

subSet

public SortedSet<K> subSet(K fromKey,
 boolean fromInclusive,
 K toKey,
 boolean toInclusive)

Returns a view of the portion of this sorted set whose elements are strictly greater than fromKey and strictly less than toKey, optionally including fromKey and toKey. This method does not exist in the standard SortedSet interface.

Note that the return value is a StoredCollection and must be treated as such; for example, its iterators must be explicitly closed.

Parameters:

fromKey - is the lower bound.

fromInclusive - is true to include fromKey.

toKey - is the upper bound.

toInclusive - is true to include toKey.

Returns:

the subset.

Throws:

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