org.zkoss.util
Interface Cache<K,V>

All Known Implementing Classes:
CacheMap, FastReadCache, MultiCache, ResourceCache, ResourceCache

public interface Cache<K,V>

Represents a cache. The interface is similar to java.util.Map but simpler to implement.

Since:
3.0.0
Author:
tomyeh

Field Summary
static int DEFAULT_LIFETIME
          The default minimal lifetime, unit=milliseconds.
static int DEFAULT_MAX_SIZE
          The default maximal allowed size.
 
Method Summary
 void clear()
          Clears all objects being cached.
 boolean containsKey(java.lang.Object key)
          Returns whether the specified key is stored.
 V get(java.lang.Object key)
          Returns the object of the specified key, or null if not found.
 int getLifetime()
          Returns the minimal lifetime, unit=milliseconds.
 int getMaxSize()
          Returns the maximal allowed size.
 V put(K key, V value)
          Stores an object to the cache.
 V remove(java.lang.Object key)
          Removes an object from the cache.
 void setLifetime(int lifetime)
          Sets the minimal lifetime.
 void setMaxSize(int maxsize)
          Sets the maximal allowed size.
 

Field Detail

DEFAULT_LIFETIME

static final int DEFAULT_LIFETIME
The default minimal lifetime, unit=milliseconds. It is 30 minutes.

See Also:
Constant Field Values

DEFAULT_MAX_SIZE

static final int DEFAULT_MAX_SIZE
The default maximal allowed size. It is 512.

See Also:
Constant Field Values
Method Detail

containsKey

boolean containsKey(java.lang.Object key)
Returns whether the specified key is stored.


get

V get(java.lang.Object key)
Returns the object of the specified key, or null if not found.


put

V put(K key,
      V value)
Stores an object to the cache.

Returns:
the previous value of the same, or null if no such value

remove

V remove(java.lang.Object key)
Removes an object from the cache.

Returns:
the object if found.

clear

void clear()
Clears all objects being cached.


getLifetime

int getLifetime()
Returns the minimal lifetime, unit=milliseconds. An mapping won't be removed by GC unless the minimal lifetime or the maximal allowed size exceeds.

See Also:
getMaxSize()

setLifetime

void setLifetime(int lifetime)
Sets the minimal lifetime. Default: DEFAULT_LIFETIME.

Parameters:
lifetime - the lifetime, unit=milliseconds; if non-positive, they will be removed immediately.
See Also:
getLifetime()

getMaxSize

int getMaxSize()
Returns the maximal allowed size. Default: DEFAULT_MAX_SIZE. An mapping won't be removed by GC unless the minimal lifetime or the maximal allowed size exceeds.

See Also:
getLifetime()

setMaxSize

void setMaxSize(int maxsize)
Sets the maximal allowed size.

See Also:
getMaxSize()


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