Interface Cache<K,V>

Type Parameters:
K - The type of the key.
V - The type of the value.
public interface Cache<K,V>
A contract that defines a semi-persistent mapping of keys and values.
Cache entries are manually added using put(K, V), and are stored in the cache until either evicted or manually removed. After storing a value, it can be accessed using get(K).

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    contains(K key)
    Returns True if the cache contains a entry with the key, or False if there is none.
    Optional<V>
    get(K key)
    Returns the value associated with key in this cache, or empty if there is no cached value for key.
    boolean
    isEmpty()
    Returns True if the cache is empty, or False if there's at least a entry stored in cache.
    void
    put(K key, V value)
    Associates value with key in this cache.
    void
    remove(K key)
    Discards any cached value for this key.
    void
    removeAll()
    Discards all entries in the cache.
    long
    size()
    Returns the number of entries in this cache.
    CacheStats
    stats()
    Returns a current snapshot of this cache's cumulative statistics, or a set of default values if the cache is not recording statistics.

  • Method Details

    • put

      void put(K key, V value)
      Associates value with key in this cache.
      If the cache previously contained a value associated with key, the old value is replaced by value.
      Parameters:
      key - The key to be used as index.
      value - The value to be stored.

    • get

      Optional<V> get(K key)
      Returns the value associated with key in this cache, or empty if there is no cached value for key.
      Parameters:
      key - The key to look for.
      Returns:
      The value stored in cache if present.

    • remove

      void remove(K key)
      Discards any cached value for this key.
      Parameters:
      key - The key to be discarded.

    • removeAll

      void removeAll()
      Discards all entries in the cache.

    • contains

      boolean contains(K key)
      Returns True if the cache contains a entry with the key, or False if there is none.
      Parameters:
      key - The key to be verified.
      Returns:
      True if the key is present.

    • size

      long size()
      Returns the number of entries in this cache.
      Returns:
      The cache size.

    • isEmpty

      boolean isEmpty()
      Returns True if the cache is empty, or False if there's at least a entry stored in cache.
      Returns:
      True if is empty.

    • stats

      CacheStats stats()
      Returns a current snapshot of this cache's cumulative statistics, or a set of default values if the cache is not recording statistics. All statistics begin at zero and never decrease over the lifetime of the cache.