PCJ API
Version 1.2

bak.pcj.adapter
Class MapToCharKeyByteMapAdapter

java.lang.Object
  extended bybak.pcj.map.AbstractCharKeyByteMap
      extended bybak.pcj.adapter.MapToCharKeyByteMapAdapter
All Implemented Interfaces:
CharKeyByteMap

public class MapToCharKeyByteMapAdapter
extends AbstractCharKeyByteMap
implements CharKeyByteMap

This class represents adaptions of Java Collections Framework maps to primitive maps from char values to byte values. 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/values or keys/values of the wrong class. However, adapters are not fast failing in the case that the underlying map should contain illegal keys or values. To implement fast failure would require every operation to check every key and value of the underlying map before doing anything. Instead validation methods are provided. They can be called using the assertion facility in the client code:

      MapToCharKeyByteMapAdapter s;
      ...
      assert s.validate();
  
or by letting the adapter throw an exception on illegal values:
      MapToCharKeyByteMapAdapter 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  Byte lastValue
          The value corresponding to the last key found by containsKey().
protected  Map map
          The underlying map.
 
Constructor Summary
MapToCharKeyByteMapAdapter(Map map)
          Creates a new adaption to a map from char values to byte values.
MapToCharKeyByteMapAdapter(Map map, boolean validate)
          Creates a new adaption to a map from char values to byte values.
 
Method Summary
 void clear()
          Clears this map.
 boolean containsKey(char key)
          Indicates whether this map contains a mapping from a specified key.
 boolean containsValue(byte value)
          Indicates whether this map contains a mapping to a specified value.
 CharKeyByteMapIterator 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.
 byte get(char key)
          Maps a specified key to a value.
 CharSet keySet()
          Returns a set view of the keys of this map.
 byte lget()
          Returns the last value corresponding to a positive result from containsKey(char).
 byte put(char key, byte value)
          Adds a mapping from a specified key to a specified value to this map.
 byte remove(char key)
          Removes the mapping from a specified key from this map.
 int size()
          Returns the size of this map.
 byte tget(char key)
          Maps a specified key to a value.
 boolean validate()
          Indicates whether the underlying map is valid for this adapter.
 ByteCollection values()
          Returns a collection view of the values in this map.
 
Methods inherited from class bak.pcj.map.AbstractCharKeyByteMap
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.CharKeyByteMap
equals, hashCode, isEmpty, putAll, trimToSize
 

Field Detail

map

protected Map map
The underlying map.


lastValue

protected Byte lastValue
The value corresponding to the last key found by containsKey().

Constructor Detail

MapToCharKeyByteMapAdapter

public MapToCharKeyByteMapAdapter(Map map)
Creates a new adaption to a map from char values to byte values.

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

MapToCharKeyByteMapAdapter

public MapToCharKeyByteMapAdapter(Map map,
                                  boolean validate)
Creates a new adaption to a map from char values to byte values. The map to adapt is optionally validated.

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

clear

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

Specified by:
clear in interface CharKeyByteMap
Overrides:
clear in class AbstractCharKeyByteMap

containsKey

public boolean containsKey(char key)
Description copied from interface: CharKeyByteMap
Indicates whether this map contains a mapping from a specified key. If the key is contained in this map, a succeeding call to lget() will return the corresponding value.

Specified by:
containsKey in interface CharKeyByteMap
Overrides:
containsKey in class AbstractCharKeyByteMap

containsValue

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

Specified by:
containsValue in interface CharKeyByteMap
Overrides:
containsValue in class AbstractCharKeyByteMap

entries

public CharKeyByteMapIterator entries()
Description copied from interface: CharKeyByteMap
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 CharKeyByteMap
Returns:
an iterator over the entries of this map.

get

public byte get(char key)
Description copied from interface: CharKeyByteMap
Maps a specified key to a value. Returns a default value as specified by the MapDefaults class if no mapping exists for the specified key.

Specified by:
get in interface CharKeyByteMap
Overrides:
get in class AbstractCharKeyByteMap

keySet

public CharSet keySet()
Description copied from interface: CharKeyByteMap
Returns a set view of the keys of this map. Removals from the returned set removes the corresponding entries in this map. Changes to the map are reflected in the set.

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

lget

public byte lget()
Description copied from interface: CharKeyByteMap
Returns the last value corresponding to a positive result from containsKey(char). This is useful for checking checking the existence of a mapping while avoiding two lookups on the same key.

Specified by:
lget in interface CharKeyByteMap
Returns:
the value corresponding to the key from the last invokation of containsKey(char).
See Also:
CharKeyByteMap.get(char), CharKeyByteMap.tget(char), CharKeyByteMap.containsKey(char)

put

public byte put(char key,
                byte value)
Description copied from interface: CharKeyByteMap
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 CharKeyByteMap
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 if a mapping from the specified key already existed in this map; otherwise returns a default value as specified by the MapDefaults class.
See Also:
MapDefaults

remove

public byte remove(char key)
Description copied from interface: CharKeyByteMap
Removes the mapping from a specified key from this map.

Specified by:
remove in interface CharKeyByteMap
Overrides:
remove in class AbstractCharKeyByteMap

size

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

Specified by:
size in interface CharKeyByteMap
Overrides:
size in class AbstractCharKeyByteMap

values

public ByteCollection values()
Description copied from interface: CharKeyByteMap
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 CharKeyByteMap
Returns:
a collection view of the values in this map.

tget

public byte tget(char key)
Description copied from interface: CharKeyByteMap
Maps a specified key to a value. This method should be used when the key is known to be in the map.

Specified by:
tget in interface CharKeyByteMap
Overrides:
tget in class AbstractCharKeyByteMap

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 Character keys, no null keys/values, and only Byte values.

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 Character keys, no null keys/values, and only Byte values.

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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