What's the difference between SoftR...
What's the difference between SoftR...
In Java, SoftReference
and WeakReference
are both classes that provide a way to reference objects without preventing them from being garbage collected, but they do so with different levels of strength and are used for different purposes.
A WeakReference
in Java is a reference that does not prevent its referent from being made eligible for garbage collection. An object that is only weakly referenced (meaning the strongest references to it are WeakReferences
) will be discarded at the next garbage collection cycle if no strong references exist. This makes WeakReference
suitable for storing metadata or as keys in a WeakHashMap
, where the entry in the map is removed automatically once the key is no longer in ordinary use elsewhere[1][2][3][5][7].
On the other hand, a SoftReference
is similar to a WeakReference
but with a softer constraint. It is less eagerly collected by the garbage collector, meaning that objects that are softly referenced will generally remain in memory longer, as long as there is sufficient memory available. The garbage collector is more likely to clear a SoftReference
only when it needs memory urgently. This behavior makes SoftReference
suitable for implementing caches, where you want the object to stay in memory as long as possible to avoid expensive recomputation or reloading, but still allow it to be collected if memory is needed[1][2][3][4][5].
In summary, the key differences are:
WeakReference
objects are cleared by the gar...expert
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