org.ozoneDB.collections
Class AbstractOzoneSet

java.lang.Object
  extended byorg.ozoneDB.OzoneObject
      extended byorg.ozoneDB.collections.AbstractOzoneCollection
          extended byorg.ozoneDB.collections.AbstractOzoneSet
All Implemented Interfaces:
java.util.Collection, OzoneCollection, org.ozoneDB.OzoneCompatible, org.ozoneDB.OzoneCompatibleOrProxy, org.ozoneDB.OzoneRemote, OzoneSet, java.io.Serializable, java.util.Set
Direct Known Subclasses:
_AbstractOzoneMap_values, _BaseTreeMap_entrySet, _BaseTreeMap_keySet, _BaseTreeMap_SubMap_entrySet, _BaseTreeMap_SubMap_keySet, BaseTreeSetImpl

public abstract class AbstractOzoneSet
extends AbstractOzoneCollection
implements OzoneSet

An abstract implementation of Set to make it easier to create your own implementations. In order to create a Set, subclass AbstractOzoneSet and implement the same methods that are required for AbstractOzoneCollection (although these methods must of course meet the requirements that Set puts on them - specifically, no element may be in the set more than once). This class simply provides implementations of equals() and hashCode() to fulfil the requirements placed on them by the Set interface.

Author:
Original author unknown, Eric Blake , Leo Mekenkamp (mind the anti-sp@m) (adaptation for ozone)
See Also:
AbstractSet, Serialized Form

Constructor Summary
protected AbstractOzoneSet()
           
 
Method Summary
 boolean equals(java.lang.Object o)
          Tests whether the given object is equal to this Set.
 java.util.Set getClientSet()
          Returns a non-ozone Set that contains the same entries as this persistent one; it is (by nature of the client-server enviromnent) always a 'deep' copy of this OzoneSet.
 int hashCode()
          Returns a hash code for this Set.
 boolean removeAll(java.util.Collection c)
          Removes from this set all elements in the given collection (optional operation).
 
Methods inherited from class org.ozoneDB.collections.AbstractOzoneCollection
add, addAll, clear, contains, containsAll, getClientCollection, isEmpty, iterator, remove, retainAll, size, toArray, toArray, toString
 
Methods inherited from class org.ozoneDB.OzoneObject
container, database, deleteRecursive, getHandle, getObjectID, handle, onActivate, onCreate, onDelete, onPassivate, requireWriteLocking, self, setContainer, toXML
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface org.ozoneDB.collections.OzoneCollection
_org_ozoneDB_internalIterator, add, addAll, clear, getClientCollection, remove, retainAll
 
Methods inherited from interface java.util.Collection
contains, containsAll, isEmpty, iterator, size, toArray, toArray
 
Methods inherited from interface org.ozoneDB.OzoneCompatibleOrProxy
getObjectID
 
Methods inherited from interface java.util.Set
add, addAll, clear, contains, containsAll, isEmpty, iterator, remove, retainAll, size, toArray, toArray
 

Constructor Detail

AbstractOzoneSet

protected AbstractOzoneSet()
Method Detail

equals

public boolean equals(java.lang.Object o)
Tests whether the given object is equal to this Set. This implementation first checks whether this set is the given object, and returns true if so. Otherwise, if o is a Set and is the same size as this one, it returns the result of calling containsAll on the given Set. Otherwise, it returns false.

Specified by:
equals in interface java.util.Collection
Parameters:
o - the Object to be tested for equality with this Set
Returns:
true if the given object is equal to this Set

hashCode

public int hashCode()
Returns a hash code for this Set. The hash code of a Set is the sum of the hash codes of all its elements, except that the hash code of null is defined to be zero. This implementation obtains an Iterator over the Set, and sums the results.

Specified by:
hashCode in interface java.util.Collection
Returns:
a hash code for this Set

removeAll

public boolean removeAll(java.util.Collection c)
Removes from this set all elements in the given collection (optional operation). This implementation uses size() to determine the smaller collection. Then, if this set is smaller, it iterates over the set, calling Iterator.remove if the collection contains the element. If this set is larger, it iterates over the collection, calling Set.remove for all elements in the collection. Note that this operation will fail if a remove methods is not supported.

Specified by:
removeAll in interface OzoneCollection
Overrides:
removeAll in class AbstractOzoneCollection
Parameters:
c - the collection of elements to remove
Returns:
true if the set was modified as a result
Throws:
java.lang.UnsupportedOperationException - if remove is not supported
java.lang.NullPointerException - if the collection is null
See Also:
AbstractCollection.remove(Object), Collection.contains(Object), Iterator.remove()

getClientSet

public java.util.Set getClientSet()

Returns a non-ozone Set that contains the same entries as this persistent one; it is (by nature of the client-server enviromnent) always a 'deep' copy of this OzoneSet. I.e. the contents of this OzoneSet instance are always copied to the client by use of serialization.

This means that if this instance holds non-ozone objects, these objects are send to the calling client by means of serialization. If this instance holds ozone objects, it actually holds proxies to these objects. These proxies are copied and send to the client, resulting in different proxies to the same ozone objects.

Specified by:
getClientSet in interface OzoneSet


Copyright © 2004 The Ozone Database Project - www.ozone-db.org. All Rights Reserved.