java.util
Interface Map<K,V>

All Known Implementing Classes:

HashMap

public interface Map<K,V>

An object that maps keys to values. A map cannot contain duplicate keys; each key can map to at most one value.

Author:

Michael Mirwaldt

Nested Class Summary

static interface

Map.Entry<K,V> A map entry (key-value pair).

Method Summary

void	clear() Removes all mappings from this map (optional operation).
boolean	containsKey(Object key) Returns true if this map contains a mapping for the specified key.
boolean	containsValue(Object value) Returns true if this map maps one or more keys to the specified value.
Set<Map.Entry<K,V>>	entrySet() Returns a set view of the mappings contained in this map.
boolean	equals(Object o) Compares the specified object with this map for equality.
V	get(Object key) Returns the value to which this map maps the specified key.
int	hashCode() Returns the hash code value for this map.
boolean	isEmpty() Returns true if this map contains no key-value mappings.
Set<K>	keySet() Returns a set view of the keys contained in this map.
V	put(K key, V value) Associates the specified value with the specified key in this map (optional operation).
void	putAll(Map<? extends K,? extends V> t) Copies all of the mappings from the specified map to this map (optional operation).
V	remove(Object key) Removes the mapping for this key from this map if it is present (optional operation).
int	size() Returns the number of key-value mappings in this map.
Collection<V>	values() Returns a collection view of the values contained in this map.

Method Detail

clear

void clear()

Removes all mappings from this map (optional operation).

containsKey

boolean containsKey(Object key)

Returns true if this map contains a mapping for the specified key.

containsValue

boolean containsValue(Object value)

Returns true if this map maps one or more keys to the specified value.

entrySet

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

Returns a set view of the mappings contained in this map.

equals

boolean equals(Object o)

Compares the specified object with this map for equality.

Overrides:

equals in class Object

get

V get(Object key)

Returns the value to which this map maps the specified key.

hashCode

int hashCode()

Returns the hash code value for this map.

Overrides:

hashCode in class Object

isEmpty

boolean isEmpty()

Returns true if this map contains no key-value mappings.

keySet

Set<K> keySet()

Returns a set view of the keys contained in this map.

put

V put(K key,
      V value)

Associates the specified value with the specified key in this map (optional operation).

putAll

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

Copies all of the mappings from the specified map to this map (optional operation).

remove

V remove(Object key)

Removes the mapping for this key from this map if it is present (optional operation).

size

int size()

Returns the number of key-value mappings in this map.

values

Collection<V> values()

Returns a collection view of the values contained in this map.