PCJ API
Version 1.2

bak.pcj.adapter
Class MapToLongKeyMapAdapter

java.lang.Object
  extended bybak.pcj.map.AbstractLongKeyMap
      extended bybak.pcj.adapter.MapToLongKeyMapAdapter
All Implemented Interfaces:
LongKeyMap

public class MapToLongKeyMapAdapter
extends AbstractLongKeyMap
implements LongKeyMap

This class represents adaptions of Java Collections Framework maps to primitive maps from long values to objects. The adapter is implemented as a wrapper around the map. Thus, changes to the underlying map are reflected by this map and vice versa.

Adapters from JCF maps to primitive map will fail if the JCF collection contains null keys or keys of the wrong class. However, adapters are not fast failing in the case that the underlying map should contain illegal keys. To implement fast failure would require every operation to check every key of the underlying map before doing anything. Instead validation methods are provided. They can be called using the assertion facility in the client code:

      MapToLongKeyMapAdapter s;
      ...
      assert s.validate();
  
or by letting the adapter throw an exception on illegal values:
      MapToLongKeyMapAdapter s;
      ...
      s.evalidate();  // Throws an exception on illegal values
  
Either way, validation must be invoked directly by the client code.

Since:
1.0

Field Summary
protected  Map map
          The underlying map.
 
Constructor Summary
MapToLongKeyMapAdapter(Map map)
          Creates a new adaption to a map from long values to objects.
MapToLongKeyMapAdapter(Map map, boolean validate)
          Creates a new adaption to a map from long values to objects.
 
Method Summary
 void clear()
          Clears this map.
 boolean containsKey(long key)
          Indicates whether this map contains a mapping from a specified key.
 boolean containsValue(Object value)
          Indicates whether this map contains a mapping to a specified value.
 LongKeyMapIterator entries()
          Returns an iterator over the entries of this map.
 void evalidate()
          Validates the map underlying this adapter and throws an exception if it is invalid.
 Object get(long key)
          Maps a specified key to a value.
 LongSet keySet()
          Returns a set view of the keys of this map.
 Object put(long key, Object value)
          Adds a mapping from a specified key to a specified value to this map.
 Object remove(long key)
          Removes the mapping from a specified key from this map.
 int size()
          Returns the size of this map.
 boolean validate()
          Indicates whether the underlying map is valid for this adapter.
 Collection values()
          Returns a collection view of the values in this map.
 
Methods inherited from class bak.pcj.map.AbstractLongKeyMap
equals, hashCode, isEmpty, putAll, toString, trimToSize
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface bak.pcj.map.LongKeyMap
equals, hashCode, isEmpty, putAll
 

Field Detail

map

protected Map map
The underlying map.

Constructor Detail

MapToLongKeyMapAdapter

public MapToLongKeyMapAdapter(Map map)
Creates a new adaption to a map from long values to objects.

Parameters:
map - the underlying map. This map must consist of keys of class Long. Otherwise a ClassCastException will be thrown by some methods.
Throws:
NullPointerException - if map is null.

MapToLongKeyMapAdapter

public MapToLongKeyMapAdapter(Map map,
                              boolean validate)
Creates a new adaption to a map from long values to objects. The map to adapt is optionally validated.

Parameters:
map - the underlying map. This map must consist of keys of class Long. Otherwise a ClassCastException will be thrown by some methods.
validate - indicates whether map should be checked for illegal keys.
Throws:
NullPointerException - if map is null.
IllegalStateException - if validate is true and map contains a null key or a key that is not of class Long.
Method Detail

clear

public void clear()
Description copied from interface: LongKeyMap
Clears this map.

Specified by:
clear in interface LongKeyMap
Overrides:
clear in class AbstractLongKeyMap

containsKey

public boolean containsKey(long key)
Description copied from interface: LongKeyMap
Indicates whether this map contains a mapping from a specified key.

Specified by:
containsKey in interface LongKeyMap
Overrides:
containsKey in class AbstractLongKeyMap

containsValue

public boolean containsValue(Object value)
Description copied from interface: LongKeyMap
Indicates whether this map contains a mapping to a specified value.

Specified by:
containsValue in interface LongKeyMap
Overrides:
containsValue in class AbstractLongKeyMap

entries

public LongKeyMapIterator entries()
Description copied from interface: LongKeyMap
Returns an iterator over the entries of this map. It is possible to remove entries from this map using the iterator provided that the concrete map supports removal of entries.

Specified by:
entries in interface LongKeyMap
Returns:
an iterator over the entries of this map.

get

public Object get(long key)
Description copied from interface: LongKeyMap
Maps a specified key to a value.

Specified by:
get in interface LongKeyMap
Overrides:
get in class AbstractLongKeyMap

keySet

public LongSet keySet()
Description copied from interface: LongKeyMap
Returns a set view of the keys of this map. The set is not directly modifiable, but changes to the map are reflected in the set.

Specified by:
keySet in interface LongKeyMap
Returns:
a set view of the keys of this map.

put

public Object put(long key,
                  Object value)
Description copied from interface: LongKeyMap
Adds a mapping from a specified key to a specified value to this map. If a mapping already exists for the specified key it is overwritten by the new mapping.

Specified by:
put in interface LongKeyMap
Parameters:
key - the key of the mapping to add to this map.
value - the value of the mapping to add to this map.
Returns:
the old value (which can be null) if a mapping from the specified key already existed in this map; returns null otherwise.

remove

public Object remove(long key)
Description copied from interface: LongKeyMap
Removes the mapping from a specified key from this map.

Specified by:
remove in interface LongKeyMap
Overrides:
remove in class AbstractLongKeyMap

size

public int size()
Description copied from interface: LongKeyMap
Returns the size of this map. The size is defined as the number of mappings from keys to values.

Specified by:
size in interface LongKeyMap
Overrides:
size in class AbstractLongKeyMap

values

public Collection values()
Description copied from interface: LongKeyMap
Returns a collection view of the values in this map. The collection is not modifiable, but changes to the map are reflected in the collection.

Specified by:
values in interface LongKeyMap
Returns:
a collection view of the values in this map.

validate

public boolean validate()
Indicates whether the underlying map is valid for this adapter. For the underlying map to be valid, it can only contain Long keys and no null keys.

Returns:
true if the underlying map is valid; returns false otherwise.

evalidate

public void evalidate()
Validates the map underlying this adapter and throws an exception if it is invalid. For the underlying map to be valid, it can only contain Long keys and no null keys.

Throws:
IllegalStateException - if the underlying map is invalid.

PCJ API
Version 1.2

Report a bug or request a feature.
Further information on the development and latest release of PCJ can be found at the project homepage.

Primitive Collections for Java is released under the GNU Lesser General Public License.
Copyright © 2002, 2003 Søren Bak. All Rights Reserved.

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