zombie.core.Collections
Class ZomboidAbstractMap<K,V>

java.lang.Object
  zombie.core.Collections.ZomboidAbstractMap<K,V>

All Implemented Interfaces:

java.util.Map<K,V>

Direct Known Subclasses:

ZomboidHashMap

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

Author:

LEMMY

Nested Class Summary

static class	ZomboidAbstractMap.SimpleEntry<K,V> An Entry maintaining a key and a value.
static class	ZomboidAbstractMap.SimpleImmutableEntry<K,V> An Entry maintaining an immutable key and value.

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

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

Method Summary

void	clear()
boolean	containsKey(java.lang.Object key)
boolean	containsValue(java.lang.Object value)
abstract java.util.Set<java.util.Map.Entry<K,V>>	entrySet()
boolean	equals(java.lang.Object o) Compares the specified object with this map for equality.
V	get(java.lang.Object key)
int	hashCode() Returns the hash code value for this map.
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.lang.String	toString() Returns a string representation of this map.
java.util.Collection<V>	values()

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Method Detail

size

public int size()

This implementation returns entrySet().size().

Specified by:

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

isEmpty

public boolean isEmpty()

This implementation returns size() == 0.

Specified by:

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

containsValue

public boolean containsValue(java.lang.Object value)

This implementation iterates over entrySet() searching for an entry with the specified value. If such an entry is found, true is returned. If the iteration terminates without finding such an entry, false is returned. Note that this implementation requires linear time in the size of the map.

Specified by:

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

Throws:

java.lang.ClassCastException

java.lang.NullPointerException

containsKey

public boolean containsKey(java.lang.Object key)

This implementation iterates over entrySet() searching for an entry with the specified key. If such an entry is found, true is returned. If the iteration terminates without finding such an entry, false is returned. Note that this implementation requires linear time in the size of the map; many implementations will override this method.

Specified by:

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

Throws:

java.lang.ClassCastException

java.lang.NullPointerException

get

public V get(java.lang.Object key)

This implementation iterates over entrySet() searching for an entry with the specified key. If such an entry is found, the entry's value is returned. If the iteration terminates without finding such an entry, null is returned. Note that this implementation requires linear time in the size of the map; many implementations will override this method.

Specified by:

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

Throws:

java.lang.ClassCastException

java.lang.NullPointerException

put

public V put(K key,
             V value)

This implementation always throws an UnsupportedOperationException.

Specified by:

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

Throws:

java.lang.UnsupportedOperationException

java.lang.ClassCastException

java.lang.NullPointerException

java.lang.IllegalArgumentException

remove

public V remove(java.lang.Object key)

This implementation iterates over entrySet() searching for an entry with the specified key. If such an entry is found, its value is obtained with its getValue operation, the entry is removed from the collection (and the backing map) with the iterator's remove operation, and the saved value is returned. If the iteration terminates without finding such an entry, null is returned. Note that this implementation requires linear time in the size of the map; many implementations will override this method.

Note that this implementation throws an UnsupportedOperationException if the entrySet iterator does not support the remove method and this map contains a mapping for the specified key.

Specified by:

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

Throws:

java.lang.UnsupportedOperationException

java.lang.ClassCastException

java.lang.NullPointerException

putAll

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

This implementation iterates over the specified map's entrySet() collection, and calls this map's put operation once for each entry returned by the iteration.

Note that this implementation throws an UnsupportedOperationException if this map does not support the put operation and the specified map is nonempty.

Specified by:

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

Throws:

java.lang.UnsupportedOperationException

java.lang.ClassCastException

java.lang.NullPointerException

java.lang.IllegalArgumentException

clear

public void clear()

This implementation calls entrySet().clear().

Note that this implementation throws an UnsupportedOperationException if the entrySet does not support the clear operation.

Specified by:

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

Throws:

java.lang.UnsupportedOperationException

keySet

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

This implementation returns a set that subclasses AbstractSet. The subclass's iterator method returns a "wrapper object" over this map's entrySet() iterator. The size method delegates to this map's size method and the contains method delegates to this map's containsKey method.

The set is created the first time this method is called, and returned in response to all subsequent calls. No synchronization is performed, so there is a slight chance that multiple calls to this method will not all return the same set.

Specified by:

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

values

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

This implementation returns a collection that subclasses AbstractCollection. The subclass's iterator method returns a "wrapper object" over this map's entrySet() iterator. The size method delegates to this map's size method and the contains method delegates to this map's containsValue method.

The collection is created the first time this method is called, and returned in response to all subsequent calls. No synchronization is performed, so there is a slight chance that multiple calls to this method will not all return the same collection.

Specified by:

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

entrySet

public abstract 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)

Compares the specified object with this map for equality. Returns true if the given object is also a map and the two maps represent the same mappings. More formally, two maps m1 and m2 represent the same mappings if m1.entrySet().equals(m2.entrySet()). This ensures that the equals method works properly across different implementations of the Map interface.

This implementation first checks if the specified object is this map; if so it returns true. Then, it checks if the specified object is a map whose size is identical to the size of this map; if not, it returns false. If so, it iterates over this map's entrySet collection, and checks that the specified map contains each mapping that this map contains. If the specified map fails to contain such a mapping, false is returned. If the iteration completes, true is returned.

Specified by:

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

Overrides:

equals in class java.lang.Object

Parameters:

o - object to be compared for equality with this map

Returns:

true if the specified object is equal to this map

hashCode

public int hashCode()

Returns the hash code value for this map. The hash code of a map is defined to be the sum of the hash codes of each entry in the map's entrySet() view. This ensures that m1.equals(m2) implies that m1.hashCode()==m2.hashCode() for any two maps m1 and m2, as required by the general contract of Object.hashCode().

This implementation iterates over entrySet(), calling hashCode() on each element (entry) in the set, and adding up the results.

Specified by:

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

Overrides:

hashCode in class java.lang.Object

Returns:

the hash code value for this map

See Also:

Map.Entry#hashCode(), Object.equals(Object), Set.equals(Object)

toString

public java.lang.String toString()

Returns a string representation of this map. The string representation consists of a list of key-value mappings in the order returned by the map's entrySet view's iterator, enclosed in braces ("{}"). Adjacent mappings are separated by the characters ", " (comma and space). Each key-value mapping is rendered as the key followed by an equals sign ("=") followed by the associated value. Keys and values are converted to strings as by String.valueOf(Object).

Overrides:

toString in class java.lang.Object

Returns:

a string representation of this map