rescuecore2.misc.collections

Class LazyMap<K,V>

java.lang.Object

rescuecore2.misc.collections.LazyMap<K,V>

Type Parameters:

K - The key type.

V - The value type.

All Implemented Interfaces:

java.util.Map<K,V>

public abstract class LazyMap<K,V>
extends java.lang.Object
implements java.util.Map<K,V>

A LazyMap is a Map that generates default values for keys that do not yet have a value. This class delegates to a real Map implementation for all methods with the exception of get(Object). If the downstream get returns a value then that value is returned to the caller. If the downstream get returns null then the createValue() method will be called and the result of that is added to the downstream map and returned.

Nested Class Summary

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

java.util.Map.Entry<K,V>

Constructor Summary

Constructors

Constructor and Description
LazyMap() Construct a LazyMap that delegates to a new HashMap.
LazyMap(java.util.Map<K,V> downstream) Construct a LazyMap that delegates to a given map.

Method Summary

Modifier and Type	Method and Description
void	clear()
boolean	containsKey(java.lang.Object key)
boolean	containsValue(java.lang.Object value)
abstract V	createValue() Construct a new value object for a key that does not yet have a value.
java.util.Set<java.util.Map.Entry<K,V>>	entrySet()
boolean	equals(java.lang.Object o)
V	get(java.lang.Object key)
int	hashCode()
boolean	isEmpty()
java.util.Set<K>	keySet()
V	put(K key, V value)
void	putAll(java.util.Map<? extends K,? extends V> m)
V	remove(java.lang.Object key)
int	size()
java.util.Collection<V>	values()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Map

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

Constructor Detail

LazyMap

public LazyMap()

Construct a LazyMap that delegates to a new HashMap.

LazyMap

public LazyMap(java.util.Map<K,V> downstream)

Construct a LazyMap that delegates to a given map.

Parameters:

downstream - The delegate map.

Method Detail

createValue

public abstract V createValue()

Construct a new value object for a key that does not yet have a value.

Returns:

A new value object.

clear

public void clear()

Specified by:

clear in interface java.util.Map<K,V>

containsKey

public boolean containsKey(java.lang.Object key)

Specified by:

containsKey in interface java.util.Map<K,V>

containsValue

public boolean containsValue(java.lang.Object value)

Specified by:

containsValue in interface java.util.Map<K,V>

entrySet

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

Specified by:

entrySet in interface java.util.Map<K,V>

equals

public boolean equals(java.lang.Object o)

Specified by:

equals in interface java.util.Map<K,V>

Overrides:

equals in class java.lang.Object

get

public V get(java.lang.Object key)

Specified by:

get in interface java.util.Map<K,V>

hashCode

public int hashCode()

Specified by:

hashCode in interface java.util.Map<K,V>

Overrides:

hashCode in class java.lang.Object

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface java.util.Map<K,V>

keySet

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

Specified by:

keySet in interface java.util.Map<K,V>

put

public V put(K key,
             V value)

Specified by:

put in interface java.util.Map<K,V>

putAll

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

Specified by:

putAll in interface java.util.Map<K,V>

remove

public V remove(java.lang.Object key)

Specified by:

remove in interface java.util.Map<K,V>

size

public int size()

Specified by:

size in interface java.util.Map<K,V>

values

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

Specified by:

values in interface java.util.Map<K,V>