Package org.zkoss.util

Interface Cache<K,V>

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

    Fields
    Modifier and Type
    Field
    Description
    static final int
    DEFAULT_LIFETIME
    The default minimal lifetime, unit=milliseconds.
    static final int
    DEFAULT_MAX_SIZE
    The default maximal allowed size.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    clear()
    Clears all objects being cached.
    boolean
    containsKey(Object key)
    Returns whether the specified key is stored.
    V
    get(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(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 Details

    • DEFAULT_LIFETIME

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

    • DEFAULT_MAX_SIZE

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

  • Method Details

    • containsKey

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

    • get

      V get(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(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:

    • 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:

    • 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:

    • setMaxSize

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