Package org.openhab.core.cache

Class ExpiringCache<V>

java.lang.Object
org.openhab.core.cache.ExpiringCache<V>
Type Parameters:
V - the type of the value
@NonNullByDefault public class ExpiringCache<V> extends Object
This is a simple expiring and reloading cache implementation. There must be provided an action in order to retrieve/calculate the value. This action will be called only if the answer from the last calculation is not valid anymore, i.e. if it is expired.
Author:
Christoph Weitkamp - Initial contribution, Martin van Wingerden - Add Duration constructor

  • Constructor Details

    • ExpiringCache

      public ExpiringCache(Duration expiry, Supplier<@Nullable V> action)
      Create a new instance.
      Parameters:
      expiry - the duration for how long the value stays valid
      action - the action to retrieve/calculate the value
      Throws:
      IllegalArgumentException - For an expire value <=0.

    • ExpiringCache

      public ExpiringCache(long expiry, Supplier<@Nullable V> action)
      Create a new instance.
      Parameters:
      expiry - the duration in milliseconds for how long the value stays valid
      action - the action to retrieve/calculate the value

  • Method Details

    • getValue

      public @Nullable V getValue()
      Returns the value - possibly from the cache, if it is still valid.

    • putValue

      public final void putValue(@Nullable V value)
      Puts a new value into the cache.
      Parameters:
      value - the new value

    • invalidateValue

      public final void invalidateValue()
      Invalidates the value in the cache.

    • refreshValue

      public @Nullable V refreshValue()
      Refreshes and returns the value in the cache.
      Returns:
      the new value

    • isExpired

      public boolean isExpired()
      Checks if the value is expired.
      Returns:
      true if the value is expired