com.sleepycat.collections
Class StoredEntrySet

java.lang.Object
  |
  +--com.sleepycat.collections.StoredContainer
        |
        +--com.sleepycat.collections.StoredCollection
              |
              +--com.sleepycat.collections.StoredEntrySet

All Implemented Interfaces:

Cloneable, Collection, Set

Direct Known Subclasses:

StoredSortedEntrySet

public class StoredEntrySet

extends StoredCollection

implements Set

The Set returned by Map.entrySet(). This class may not be instantiated directly. Contrary to what is stated by Map.entrySet() this class does support the add(java.lang.Object) and StoredCollection.addAll(java.util.Collection) methods.

The Map.Entry.setValue(java.lang.Object) method of the Map.Entry objects that are returned by this class and its iterators behaves just as the StoredIterator.set(java.lang.Object) method does.

Note that this class does not conform to the standard Java collections interface in the following ways:

• The StoredContainer.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

Method Summary

boolean	add(Object mapEntry) Adds the specified element to this set if it is not already present (optional operation).
boolean	contains(Object mapEntry) Returns true if this set contains the specified element.
boolean	remove(Object mapEntry) Removes the specified element from this set if it is present (optional operation).
String	toString() Converts the collection to a string representation for debugging.

Methods inherited from class com.sleepycat.collections.StoredCollection

addAll, containsAll, equals, iterator, iterator, join, removeAll, retainAll, toArray, toArray, toList

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, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Set

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

Method Detail

add

public boolean add(Object mapEntry)

Adds the specified element to this set if it is not already present (optional operation). This method conforms to the Set.add(java.lang.Object) interface.

Specified by:

add in interface Set

Parameters:

mapEntry - must be a Map.Entry instance.

Returns:

true if the key-value pair was added to the set (and was not previously present).

Throws:

UnsupportedOperationException - if the collection is read-only.

ClassCastException - if the mapEntry is not a Map.Entry instance.

RuntimeExceptionWrapper - if a DatabaseException is thrown.

remove

public boolean remove(Object mapEntry)

Removes the specified element from this set if it is present (optional operation). This method conforms to the Set.remove(java.lang.Object) interface.

Specified by:

remove in interface Set

Parameters:

mapEntry - is a Map.Entry instance to be removed.

Returns:

true if the key-value pair was removed from the set, or false if the mapEntry is not a Map.Entry instance or is not present in the set.

Throws:

UnsupportedOperationException - if the collection is read-only.

RuntimeExceptionWrapper - if a DatabaseException is thrown.

contains

public boolean contains(Object mapEntry)

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

Specified by:

contains in interface Set

Parameters:

mapEntry - is a Map.Entry instance to be checked.

Returns:

true if the key-value pair is present in the set, or false if the mapEntry is not a Map.Entry instance or is not present in the set.

Throws:

RuntimeExceptionWrapper - if a DatabaseException is thrown.

toString

public String toString()

Description copied from class: StoredCollection

Converts the collection to a string representation for debugging. WARNING: All elements will be converted to strings and returned and therefore the returned string may be very large.

Overrides:

toString in class StoredCollection

Returns:

the string representation.