com::sleepycat::collections::StoredKeySet Class Reference

Inheritance diagram for com::sleepycat::collections::StoredKeySet:

Public Member Functions
	StoredKeySet (Database database, EntryBinding keyBinding, boolean writeAllowed)
boolean	add (Object key)
boolean	remove (Object key)
boolean	contains (Object key)

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Detailed Description

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:

• The 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.

Author:

Mark Hayes

Definition at line 40 of file StoredKeySet.java.

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Constructor & Destructor Documentation

com::sleepycat::collections::StoredKeySet::StoredKeySet (  Database  database, EntryBinding  keyBinding, boolean  writeAllowed )  [inline]

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. Exceptions: IllegalArgumentException  if formats are not consistently defined or a parameter is invalid. RuntimeExceptionWrapper  if a DatabaseException is thrown. Definition at line 59 of file StoredKeySet.java.

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Member Function Documentation

boolean com::sleepycat::collections::StoredKeySet::add (  Object  key  )  [inline]

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 interface. Exceptions: UnsupportedOperationException  if the collection is indexed, or if the collection is read-only. RuntimeExceptionWrapper  if a DatabaseException is thrown. Definition at line 84 of file StoredKeySet.java. References com::sleepycat::collections::DataCursor::putNoOverwrite().

boolean com::sleepycat::collections::StoredKeySet::contains (  Object  key  )  [inline]

Returns true if this set contains the specified key. This method conforms to the Set#contains interface. Exceptions: RuntimeExceptionWrapper  if a DatabaseException is thrown. Definition at line 124 of file StoredKeySet.java.

boolean com::sleepycat::collections::StoredKeySet::remove (  Object  key  )  [inline]

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 interface. Exceptions: UnsupportedOperationException  if the collection is read-only. RuntimeExceptionWrapper  if a DatabaseException is thrown. Definition at line 112 of file StoredKeySet.java.

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The documentation for this class was generated from the following file:

• /home/huihoo/src/db/db-4.4.16/java/src/com/sleepycat/collections/StoredKeySet.java

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