Package net.sf.jett.model

Class HashMapWrapper<K,V>

java.lang.Object

java.util.AbstractMap<K,V>

java.util.HashMap<K,V>

net.sf.jett.model.HashMapWrapper<K,V>

public class HashMapWrapper<K,V>
extends java.util.HashMap<K,V>

A HashMapWrapper is a HashMap that "wraps" another HashMap. All mappings in this map "override" any mappings in the wrapped map. Many HashMapWrappers can be used to wrap a single map, to avoid the need to clone a single map multiple times. This wrapper doesn't necessarily override all Map methods.

Since:

0.9.1

Author:

Randy Gettman

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class java.util.AbstractMap

java.util.AbstractMap.SimpleEntry<K extends java.lang.Object,V extends java.lang.Object>, java.util.AbstractMap.SimpleImmutableEntry<K extends java.lang.Object,V extends java.lang.Object>

Nested classes/interfaces inherited from interface java.util.Map

java.util.Map.Entry<K extends java.lang.Object,V extends java.lang.Object>

Constructor Summary

Constructors

Constructor	Description
HashMapWrapper(java.util.Map<K,V> otherMap)	Constructs a HashMapWrapper that wraps the given Map.

Method Summary

Modifier and Type	Method	Description
void	clear()	Clears all entries in this map and in the wrapped map.
boolean	containsKey(java.lang.Object key)	Looks in this map, and if not found, looks in the wrapped map.
boolean	containsValue(java.lang.Object value)	Looks in this map, and if not found, looks in the wrapped map.
java.util.Set<java.util.Map.Entry<K,V>>	entrySet()	Returns a Set of all entries in this map and the wrapped map, with this map overriding any entries in the wrapped map.
V	get(java.lang.Object key)	Returns the value from this map to which the key is mapped, or from the wrapped map if not present in this map.
boolean	isEmpty()	Returns true if this map and the wrapped map are both empty.
java.util.Set<K>	keySet()	Returns a Set of all keys in this map and the wrapped map, with this map overriding any keys in the wrapped map.
V	put(K key, V value)	Maps the given key to the given value in this map, never the wrapped map.
void	putAll(java.util.Map<? extends K,? extends V> map)	Puts all entries from the given map into this map, never the wrapped map.
V	remove(java.lang.Object key)	Removes the entry associated with this key from this map, never the wrapped map.
int	size()	Returns the number of mappings in this map unioned with the wrapped map.
java.util.Collection<V>	values()	Returns a Collection of all values in this map and the wrapped map, with this map overriding any values in the wrapped map with the same key.

Methods inherited from class java.util.AbstractMap

equals, hashCode, toString

Methods inherited from class java.util.HashMap

clone, compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAll

Methods inherited from interface java.util.Map

entry, equals, hashCode, of, of, of, of, of, of, of, of, of, of, of, ofEntries

Methods inherited from class java.lang.Object

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

Constructor Detail

HashMapWrapper

public HashMapWrapper(java.util.Map<K,V> otherMap)

Constructs a HashMapWrapper that wraps the given Map.

Parameters:

otherMap - Another Map to wrap.

Method Detail

clear

public void clear()

Clears all entries in this map and in the wrapped map.

Overrides:

clear in class java.util.HashMap<K,V>

containsKey

public boolean containsKey(java.lang.Object key)

Looks in this map, and if not found, looks in the wrapped map.

Overrides:

containsKey in class java.util.HashMap<K,V>

Parameters:

key - A key that may be present in this map or in the wrapped map.

Returns:

If this map or the wrapped map contains the key.

containsValue

public boolean containsValue(java.lang.Object value)

Looks in this map, and if not found, looks in the wrapped map.

Overrides:

containsValue in class java.util.HashMap<K,V>

Parameters:

value - A value that may be present in this map or in the wrapped map.

Returns:

If this map or the wrapped map contains the value.

entrySet

public java.util.Set<java.util.Map.Entry<K,V>> entrySet()

Returns a Set of all entries in this map and the wrapped map, with this map overriding any entries in the wrapped map. Changes to the returned Set do not write through to this map.

Overrides:

entrySet in class java.util.HashMap<K,V>

Returns:

A Set of mappings in this map and the wrapped map.

get

public V get(java.lang.Object key)

Returns the value from this map to which the key is mapped, or from the wrapped map if not present in this map.

Overrides:

get in class java.util.HashMap<K,V>

Parameters:

key - The key.

Returns:

The value, if the key is present in either this map or the wrapped map, or null if not present.

isEmpty

public boolean isEmpty()

Returns true if this map and the wrapped map are both empty.

Overrides:

isEmpty in class java.util.HashMap<K,V>

Returns:

true if this map and the wrapped map are both empty.

keySet

public java.util.Set<K> keySet()

Returns a Set of all keys in this map and the wrapped map, with this map overriding any keys in the wrapped map. Changes to the returned Set do not write through to this map.

Overrides:

keySet in class java.util.HashMap<K,V>

Returns:

A Set of keys in this map and the wrapped map.

put

public V put(K key,
             V value)

Maps the given key to the given value in this map, never the wrapped map.

Overrides:

put in class java.util.HashMap<K,V>

Parameters:

key - The key to map.

value - The value to map.

Returns:

The old value, whether it came from this map or the wrapped map.

putAll

public void putAll(java.util.Map<? extends K,? extends V> map)

Puts all entries from the given map into this map, never the wrapped map.

Overrides:

putAll in class java.util.HashMap<K,V>

Parameters:

map - Another map.

remove

public V remove(java.lang.Object key)

Removes the entry associated with this key from this map, never the wrapped map.

Overrides:

remove in class java.util.HashMap<K,V>

Parameters:

key - The key associated with the entry to remove.

Returns:

The value that was associated from this map, never the wrapped map.

size

public int size()

Returns the number of mappings in this map unioned with the wrapped map. Any keys present in both maps are counted only once.

Overrides:

size in class java.util.HashMap<K,V>

Returns:

The number of mappings.

values

public java.util.Collection<V> values()

Returns a Collection of all values in this map and the wrapped map, with this map overriding any values in the wrapped map with the same key. Changes to the returned Collection do not write through to this map.

Overrides:

values in class java.util.HashMap<K,V>

Returns:

A Collection of values in this map and the wrapped map.