com.atlassian.jira.util.collect

Class CompositeMap<K,V>

java.lang.Object

java.util.AbstractMap<K,V>

com.atlassian.jira.util.collect.CompositeMap<K,V>

All Implemented Interfaces:

Map<K,V>

@NotThreadSafe
public class CompositeMap<K,V>
extends AbstractMap<K,V>

Provides a union view of two maps.

Restrictions:

• The supplied maps become the property of the new map. They should not be accessed directly in any way after the composite map is created. The result of such access is left undefined.
• The mutability of this map depends on that of the first map. For efficiency reasons, this class uses the first map to hold updated state. If the first map is immutable, then this map will be, too. The second map in never modified by this class.
• CompositeMap is not synchronized and is not thread-safe. If you wish to use this map from multiple threads concurrently, you must use appropriate synchronization. The simplest approach is to wrap this map using Collections.synchronizedMap(Map). This class will behave in an undefined manner if accessed by concurrent threads without synchronization.

Nested Class Summary

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

AbstractMap.SimpleEntry<K,V>, AbstractMap.SimpleImmutableEntry<K,V>

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

Map.Entry<K,V>

Method Summary

Modifier and Type	Method and Description
void	clear()
boolean	containsKey(Object key)
Set<Map.Entry<K,V>>	entrySet()
V	get(Object key)
boolean	isEmpty()
Set<K>	keySet()
static <K,V> Map<K,V>	of(Map<K,V> one, Map<K,V> two) Create a new CompositeMap with two composited Map instances.
V	put(K key, V value)
void	putAll(Map<? extends K,? extends V> m)
V	remove(Object key)
int	size()

Methods inherited from class java.util.AbstractMap

clone, containsValue, equals, hashCode, toString, values

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Map

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

Method Detail

of

public static <K,V> Map<K,V> of(Map<K,V> one,
                                Map<K,V> two)

Create a new CompositeMap with two composited Map instances.

Parameters:

one - the first Map to be composited, values here override values in the second.

two - the second Map to be composited

Returns:

the CompositeMap, or one itself if two is empty

Throws:

IllegalArgumentException - if either map is null

keySet

public Set<K> keySet()

Specified by:

keySet in interface Map<K,V>

Overrides:

keySet in class AbstractMap<K,V>

entrySet

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

Specified by:

entrySet in interface Map<K,V>

Specified by:

entrySet in class AbstractMap<K,V>

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Map<K,V>

Overrides:

isEmpty in class AbstractMap<K,V>

size

public int size()

Specified by:

size in interface Map<K,V>

Overrides:

size in class AbstractMap<K,V>

containsKey

public boolean containsKey(Object key)

Specified by:

containsKey in interface Map<K,V>

Overrides:

containsKey in class AbstractMap<K,V>

get

public V get(Object key)

Specified by:

get in interface Map<K,V>

Overrides:

get in class AbstractMap<K,V>

put

public V put(K key,
             V value)

Specified by:

put in interface Map<K,V>

Overrides:

put in class AbstractMap<K,V>

putAll

public void putAll(Map<? extends K,? extends V> m)

Specified by:

putAll in interface Map<K,V>

Overrides:

putAll in class AbstractMap<K,V>

remove

public V remove(Object key)

Specified by:

remove in interface Map<K,V>

Overrides:

remove in class AbstractMap<K,V>

clear

public void clear()

Specified by:

clear in interface Map<K,V>

Overrides:

clear in class AbstractMap<K,V>