Package org.zkoss.util

Interface Cache<K,​V>

    • Field Summary

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

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      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()