Package org.glassfish.jersey.internal.guava

Interface LoadingCache<K,​V>

  • All Superinterfaces:
    Cache<K,​V>, Function<K,​V>
    public interface LoadingCache<K,​V>
extends Cache<K,​V>, Function<K,​V>
    A semi-persistent mapping from keys to values. Values are automatically loaded by the cache, and are stored in the cache until either evicted or manually invalidated.

    Implementations of this interface are expected to be thread-safe, and can be safely accessed by multiple concurrent threads.

    When evaluated as a Function, a cache yields the same result as invoking #getUnchecked.

    Note that while this class is still annotated as Beta, the API is frozen from a consumer's standpoint. In other words existing methods are all considered non-Beta and won't be changed without going through an 18 month deprecation cycle; however new methods may be added at any time.

    Since:
    11.0
    Author:
    Charles Fry

    • Method Detail

      • get

        V get​(K key)
throws ExecutionException
        Returns the value associated with key in this cache, first loading that value if necessary. No observable state associated with this cache is modified until loading completes.

        If another call to get(K) or #getUnchecked is currently loading the value for key, simply waits for that thread to finish and returns its loaded value. Note that multiple threads can concurrently load values for distinct keys.

        Caches loaded by a CacheLoader will call CacheLoader.load(K) to load new values into the cache. Newly loaded values are added to the cache using Cache.asMap().putIfAbsent after loading has completed; if another value was associated with key while the new value was loading then a removal notification will be sent for the new value.

        If the cache loader associated with this cache is known not to throw checked exceptions, then prefer #getUnchecked over this method.

        Throws:
        ExecutionException - if a checked exception was thrown while loading the value. ( ExecutionException is thrown even if computation was interrupted by an InterruptedException.)
        UncheckedExecutionException - if an unchecked exception was thrown while loading the value
        ExecutionError - if an error was thrown while loading the value

      • apply

        @Deprecated
V apply​(K key)
        Deprecated.
        Provided to satisfy the Function interface; use get(K) or #getUnchecked instead.
        Specified by:
        apply in interface Function<K,​V>
        Throws:
        UncheckedExecutionException - if an exception was thrown while loading the value. (As described in the documentation for #getUnchecked, LoadingCache should be used as a Function only with cache loaders that throw only unchecked exceptions.)