net.sf.molae.pipe.hash
Class ListBackedMap

java.lang.Object
  |
  +--java.util.AbstractMap
        |
        +--net.sf.molae.pipe.genimpl.KeySetBasedMap
              |
              +--net.sf.molae.pipe.hash.ListBackedMap

All Implemented Interfaces:

Map

public final class ListBackedMap

extends KeySetBasedMap

This class implements the map interface with a list implementation. Prerequisite for this implementation is that

• A set of allowed keys must be defined.
• The hash keys within this set are unique

More formally: Be K the set of keys, then

∀ k₁, k₂ ∈ K k₁ ≠ k₂ &there4 h(k₁) ≠ h(k₂)

For a good implementation the key set should not have big gaps and the maximum key value should not be too big. Null values are allowed. Null keys are not allowed.

Inner classes inherited from class java.util.Map

Map.Entry

Constructor Summary

ListBackedMap(List universe)
Constructs a new ListBackedMap.

ListBackedMap(List universe, List values)
Constructs a new ListBackedMap.

ListBackedMap(Set universe)
Constructs a new ListBackedMap.

Method Summary

Object	get(Object key) Returns the value to which this map maps the specified key.
Set	keySet() Returns a set view of the keys contained in this map.
static Map	listAsMap(List base) Returns a map that maps integers to the list entry at the corresponding position in the base list.
Object	put(Object key, Object value)
Object	remove(Object key) Removes the mapping for this key from this map if present (optional operation).

Methods inherited from class net.sf.molae.pipe.genimpl.KeySetBasedMap

clear, containsKey, entrySet, size

Methods inherited from class java.util.AbstractMap

containsValue, equals, hashCode, isEmpty, putAll, toString, values

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

ListBackedMap

public ListBackedMap(List universe,
                     List values)

Constructs a new ListBackedMap.

Parameters:

universe - a collection containing all possible keys

values - values of the map

ListBackedMap

public ListBackedMap(List universe)

Constructs a new ListBackedMap.

Parameters:

universe - a collection containing all possible keys

Throws:

NullPointerException - if the specified object is null

ListBackedMap

public ListBackedMap(Set universe)

Constructs a new ListBackedMap.

Parameters:

universe - a collection containing all possible keys

Throws:

NullPointerException - if the specified object is null

Method Detail

listAsMap

public static Map listAsMap(List base)

Returns a map that maps integers to the list entry at the corresponding position in the base list.

Parameters:

base - the base list.

Returns:

a map that maps integers to the list entry at the corresponding position in the base list.

get

public Object get(Object key)

Description copied from class: KeySetBasedMap

Returns the value to which this map maps the specified key. Returns null if the map contains no mapping for this key.

Overrides:

get in class KeySetBasedMap

Following copied from class: net.sf.molae.pipe.genimpl.KeySetBasedMap

Parameters:

key - key whose associated value is to be returned.

Returns:

the value to which this map maps the specified key.

Throws:

ClassCastException - if the specified key is of an inappropriate type for this map.

NullPointerException - if the key is null and this map does not not permit null keys.

put

public Object put(Object key,
                  Object value)

Overrides:

put in class AbstractMap

remove

public Object remove(Object key)

Description copied from class: KeySetBasedMap

Removes the mapping for this key from this map if present (optional operation).

This implementation removes the specified key from the keySet().

Overrides:

remove in class KeySetBasedMap

Following copied from class: net.sf.molae.pipe.genimpl.KeySetBasedMap

Parameters:

key - key whose mapping is to be removed from the map.

Returns:

previous value associated with specified key, or null if there was no entry for key. (A null return can also indicate that the map previously associated null with the specified key, if the implementation supports null values.)

Throws:

UnsupportedOperationException - if the remove operation is not supported by the key set.

keySet

public Set keySet()

Description copied from class: KeySetBasedMap

Returns a set view of the keys contained in this map.

Overrides:

keySet in class KeySetBasedMap

Following copied from class: net.sf.molae.pipe.genimpl.KeySetBasedMap

Returns:

a set view of the keys contained in this map.