public static class Reference2ReferenceFunctions.EmptyFunction<K,V> extends AbstractReference2ReferenceFunction<K,V> implements Serializable, Cloneable
This class may be useful to implement your own in case you subclass a type-specific function.
Modifier and Type | Method and Description |
---|---|
void |
clear()
Removes all associations from this function (optional operation).
|
Object |
clone() |
boolean |
containsKey(Object k)
Returns true if this function contains a mapping for the specified key.
|
V |
defaultReturnValue()
Gets the default return value.
|
void |
defaultReturnValue(V defRetValue)
Sets the default return value.
|
V |
get(Object k)
Returns the value associated by this function to the specified key.
|
int |
size()
Returns the intended number of keys in this function, or -1 if no such number exists.
|
put, remove
public V get(Object k)
Function
get
in interface Function<K,V>
k
- the key.null
if no value was present for the given key.Map.get(Object)
public boolean containsKey(Object k)
Function
Note that for some kind of functions (e.g., hashes) this method will always return true.
containsKey
in interface Function<K,V>
k
- the key.key
.Map.containsKey(Object)
public V defaultReturnValue()
Reference2ReferenceFunction
defaultReturnValue
in interface Reference2ReferenceFunction<K,V>
defaultReturnValue
in class AbstractReference2ReferenceFunction<K,V>
public void defaultReturnValue(V defRetValue)
Reference2ReferenceFunction
get()
, put()
and remove()
to
denote that the map does not contain the specified key. It must be
0/false
/null
by default.defaultReturnValue
in interface Reference2ReferenceFunction<K,V>
defaultReturnValue
in class AbstractReference2ReferenceFunction<K,V>
defRetValue
- the new default return value.Reference2ReferenceFunction.defaultReturnValue()
public int size()
Function
Most function implementations will have some knowledge of the intended number of keys in their domain. In some cases, however, this might not be possible.
public void clear()
Function
clear
in interface Function<K,V>
clear
in class AbstractReference2ReferenceFunction<K,V>
Map.clear()