Interface CachePolicy

  • All Known Implementing Classes:
    LRUCachePolicy, SynchronizedCachePolicy, TimedCachePolicy

    public interface CachePolicy
    Interface that specifies a policy for caches.

    Implementation classes can implement a LRU policy, a random one, a MRU one, or any other suitable policy.

    Version:
    $Revision$
    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      void create()  
      void destroy()  
      void flush()
      Flushes the cached objects from the cache.
      java.lang.Object get​(java.lang.Object key)
      Returns the object paired with the specified key if it's present in the cache, otherwise must return null.
      void insert​(java.lang.Object key, java.lang.Object object)
      Inserts the specified object into the cache following the implemented policy.
      java.lang.Object peek​(java.lang.Object key)
      Returns the object paired with the specified key if it's present in the cache, otherwise must return null.
      void remove​(java.lang.Object key)
      Remove the cached object paired with the specified key.
      int size()  
      void start()  
      void stop()  
    • Method Detail

      • get

        java.lang.Object get​(java.lang.Object key)
        Returns the object paired with the specified key if it's present in the cache, otherwise must return null.
        Implementations of this method must have complexity of order O(1). Differently from peek(java.lang.Object) this method not only return whether the object is present in the cache or not, but also applies the implemented policy that will "refresh" the cached object in the cache, because this cached object was really requested.
        Parameters:
        key - the key paired with the object
        Returns:
        the object
        See Also:
        peek(java.lang.Object)
      • peek

        java.lang.Object peek​(java.lang.Object key)
        Returns the object paired with the specified key if it's present in the cache, otherwise must return null.
        Implementations of this method must have complexity of order O(1). This method should not apply the implemented caching policy to the object paired with the given key, so that a client can query if an object is cached without "refresh" its cache status. Real requests for the object must be done using get(java.lang.Object).
        Parameters:
        key - the key paired with the object
        Returns:
        the object
        See Also:
        get(java.lang.Object)
      • insert

        void insert​(java.lang.Object key,
                    java.lang.Object object)
        Inserts the specified object into the cache following the implemented policy.
        Implementations of this method must have complexity of order O(1).
        Parameters:
        key - the key paired with the object
        object - the object to cache
        See Also:
        remove(java.lang.Object)
      • remove

        void remove​(java.lang.Object key)
        Remove the cached object paired with the specified key.
        Implementations of this method must have complexity of order O(1).
        Parameters:
        key - the key paired with the object
        See Also:
        insert(java.lang.Object, java.lang.Object)
      • flush

        void flush()
        Flushes the cached objects from the cache.
      • size

        int size()
        Returns:
        the size of the cache
      • create

        void create()
             throws java.lang.Exception
        Throws:
        java.lang.Exception
      • start

        void start()
            throws java.lang.Exception
        Throws:
        java.lang.Exception
      • stop

        void stop()
      • destroy

        void destroy()