org.jaffa.cache
Interface ICache

All Known Implementing Classes:
SimpleCache, WeakCache

public interface ICache

This is the interface for the various cache implementations.

Author:
GautamJ

Method Summary
 void clear()
          Removes all mappings from this cache.
 boolean containsKey(Object key)
          Returns true if this cache contains a mapping for the specified key.
 Object get(Object key)
          Returns the value to which cache maps the specified key.
 boolean isEmpty()
          Returns true if this cache contains no key-value mappings.
 Set keySet()
          Returns a set view of the keys contained in this cache.
 void put(Object key, Object value)
          Associates the specified value with the specified key in this cache.
 void remove(Object key)
          Removes the mapping for this key from this cache if it is present.
 int size()
          Returns the number of key-value mappings in this cache.
 

Method Detail

get

public Object get(Object key)
Returns the value to which cache maps the specified key. Returns null if the cache contains no mapping for this key. A return value of null does not necessarily indicate that the cache contains no mapping for the key; it's also possible that the cache explicitly maps the key to null. The containsKey operation may be used to distinguish these two cases.

Parameters:
key - key whose associated value is to be returned.
Returns:
the value to which this cache maps the specified key, or null if the cache contains no mapping for this key.

put

public void put(Object key,
                Object value)
Associates the specified value with the specified key in this cache. If the cache previously contained a mapping for this key, the old value is replaced by the specified value.

Parameters:
key - key with which the specified value is to be associated.
value - value to be associated with the specified key.

clear

public void clear()
Removes all mappings from this cache.


containsKey

public boolean containsKey(Object key)
Returns true if this cache contains a mapping for the specified key.

Parameters:
key - key whose presence in this cache is to be tested.
Returns:
true if this cache contains a mapping for the specified key.

isEmpty

public boolean isEmpty()
Returns true if this cache contains no key-value mappings.

Returns:
true if this cache contains no key-value mappings.

keySet

public Set keySet()
Returns a set view of the keys contained in this cache. The set is backed by the cache, so changes to the cache are reflected in the set, and vice-versa. If the cache is modified while an iteration over the set is in progress, the results of the iteration are undefined.

Returns:
a set view of the keys contained in this cache.

remove

public void remove(Object key)
Removes the mapping for this key from this cache if it is present.

Parameters:
key - key whose mapping is to be removed from the cache.

size

public int size()
Returns the number of key-value mappings in this cache.

Returns:
the number of key-value mappings in this cache.


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